Postnatal Fish Oil Supplementation in High-Risk Infants to Prevent Allergy: Randomized Controlled Trial Effect of prolonged and exclusive breast feeding on risk of allergy and asthma: cluster randomised trial Influence of host and environmental factors on wheezing severity in infants: findings from the PARIS birth cohort Supplementation with vitamin A early in life and subsequent risk of asthma Home Dampness and Molds, Parental Atopy, and Asthma in Childhood: A Six-Year Population-Based Cohort Study Maternal smoking in pregnancy and asthma in preschool children: a pooled analysis of eight birth cohorts. Prenatal Exposure to Bisphenol A and Child Wheeze from Birth to 3 Years of Age Prenatal and postnatal bisphenol A exposure and asthma development among inner-city children. Duration and exclusiveness of breastfeeding and childhood asthma-related symptoms The impact of early nutrition on incidence of allergic manifestations and common respiratory illnesses in children. Maternal B vitamin intake during pregnancy and wheeze and eczema in Japanese infants aged 16-24 months: the Osaka Maternal and Child Health Study. Early-life air pollution and asthma risk in minority children. The GALA II and SAGE II studies. Association of consumption of products containing milk fat with reduced asthma risk in pre-school children: the PIAMA birth cohort study Cat ownership is a risk factor for the development of anti-cat IgE but not current wheeze at age 5 years in an inner-city cohort. Early daycare is associated with an increase in airway symptoms in early childhood but is no protection against asthma or atopy at 8 years. Increased asthma and respiratory symptoms in children exposed to petrochemical pollution. Folic acid supplementation in early pregnancy and asthma in children aged 6 years. A Randomized Prospective Double Blind Controlled Trial on Effects of Long-Term Consumption of Fermented Milk Containing Lactobacillus casei in Pre-School Children With Allergic Asthma and/or Rhinitis The introduction of allergenic foods and the development of reported wheezing and eczema in childhood: the Generation R study. The causal direction in the association between respiratory syncytial virus hospitalization and asthma. Allergen exposure in infancy and the development of sensitization, wheeze, and asthma at 4 years. Early introduction of oats associated with decreased risk of persistent asthma and early introduction of fish with decreased risk of allergic rhinitis. Consumption of organic foods and risk of atopic disease during the first 2 years of life in the Netherlands. Prevention of asthma in genetically susceptible children: a multifaceted intervention trial focussed on feasibility in general practice. A non-hydrolyzed, fermented milk formula reduces digestive and respiratory events in infants at high risk of allergy Early-life allergen exposure and atopy, asthma, and wheeze up to 6 years of age. Partial Protein-Hydrolyzed Infant Formula Decreased Food Sensitization but Not Allergic Diseases in a Prospective Birth Cohort Study Maternal smoking during pregnancy, prematurity and recurrent wheezing in early childhood. Early life environmental control: effect on symptoms, sensitization, and lung function at age 3 years. Maternal Smoking and Environmental Tobacco Smoke Exposure and the Risk of Allergic Diseases in Japanese Infants: The Osaka Maternal and Child Health Study Prevention of allergic disease during childhood by allergen avoidance: the Isle of Wight prevention study. Prevention of asthma during the first 5 years of life: a randomized controlled trial. Maternal exposure to magnetic fields during pregnancy in relation to the risk of asthma in offspring. Infant sleeping environment and asthma at 7 years: a prospective cohort study. Health risks of early swimming pool attendance. Effects of pets on asthma development up to 8 years of age: the PIAMA study Serum micronutrient concentrations and childhood asthma: the PIAMA birth cohort study. Breast feeding and allergic diseases in infants—a prospective birth cohort study Fish oil supplementation in pregnancy modifies neonatal allergen-specific immune responses and clinical outcomes in infants at high risk of atopy: a randomized, controlled trial. The Canadian Childhood Asthma Primary Prevention Study: outcomes at 7 years of age. Exposure to cat allergen, maternal history of asthma, and wheezing in first 5 years of life Breastfeeding protects against current asthma up to 6 years of age. Early exposure to house-dust mite and cat allergens and development of childhood asthma: a cohort study Airway inflammation in probiotic-treated children at 5 years.
BACKGROUND AND OBJECTIVE : Relative deficiency of dietary omega 3 polyunsaturated fatty acids ( n-3 PUFA ) has been implicated in the rising allergy prevalence in Westernized countries . Fish oil supplementation may provide an intervention strategy for primary allergy prevention . The objective of this study was to assess the effect of fish oil n-3 PUFA supplementation from birth to 6 months of age on infant allergic disease . METHODS : In a double-blind r and omized controlled trial , 420 infants at high atopic risk received a daily supplement of fish oil containing 280 mg docosahexaenoic acid and 110 mg eicosapentaenoic acid or a control ( olive oil ) , from birth to age 6 months . PUFA levels were measured in 6-month-old infants ’ erythrocytes and plasma and their mothers ’ breast milk . Eczema , food allergy , asthma and sensitization were assessed in 323 infants for whom clinical follow-up was completed at 12 months of age . RESULTS : At 6 months of age , infant docosahexaenoic acid and eicosapentaenoic acid levels were significantly higher ( both P < .05 ) and erythrocyte arachidonic acid levels were lower ( P = .003 ) in the fish oil group . Although n-3 PUFA levels at 6 months were associated with lower risk of eczema ( P = .033 ) and recurrent wheeze ( P = .027 ) , the association with eczema was not significant after multiple comparisons and there was no effect of the intervention per se on the primary study outcomes . Specifically , between-group comparisons revealed no differences in the occurrence of allergic outcomes including sensitization , eczema , asthma , or food allergy . CONCLUSIONS : Postnatal fish oil supplementation improved infant n-3 status but did not prevent childhood allergic disease Objective To assess whether exclusive and prolonged breast feeding reduces the risk of childhood asthma and allergy by age 6.5 years . Design Cluster r and omised trial . Setting 31 Belarussian maternity hospitals and their affiliated polyclinics . Participants A total of 17 046 mother-infant pairs were enrolled , of whom 13 889 ( 81.5 % ) were followed up at age 6.5 years . Intervention Breastfeeding promotion intervention modelled on the WHO/UNICEF baby friendly hospital initiative . Main outcome measures International study of asthma and allergies in childhood ( ISAAC ) question naire and skin prick tests of five inhalant antigens . Results The experimental intervention led to a large increase in exclusive breast feeding at 3 months ( 44.3 % v 6.4 % ; P<0.001 ) and a significantly higher prevalence of any breast feeding at all ages up to and including 12 months . The experimental group had no reduction in risks of allergic symptoms and diagnoses or positive skin prick tests . In fact , after exclusion of six sites ( three experimental and three control ) with suspiciously high rates of positive skin prick tests , risks were significantly increased in the experimental group for four of the five antigens . Conclusions These results do not support a protective effect of prolonged and exclusive breast feeding on asthma or allergy . Trial registration Current Controlled Trials IS RCT N37687716 Determinants of wheezing severity are poorly documented in infants . Animal models suggest that vitamin A deficiency affects lung development adversely and promotes airway hyperresponsiveness , and may predispose to an increased risk of asthma .  We examined the long-term effects of vitamin A supplementation early in life on later  asthma risk . In 2006–2008 , we revisited participants from two cohorts in rural Nepal who were enrolled in r and omised trials of vitamin A supplementation . The first cohort received  vitamin A or placebo  for < 16 months during their pre-school years ( 1989–1991 ) . The second cohort was born to mothers who received vitamin A , & bgr;-carotene or placebo before , during and after pregnancy ( 1994–1997 ) . At follow-up , we asked about asthma symptoms and performed spirometry .  Out of 6,421 subjects eligible to participate , 5,430 ( 85 % ) responded to our respiratory survey . Wheezing prevalence during the previous year was 4.8 % in participants aged 9–13 yrs and 6.6 % in participants aged 14–23 yrs . We found no differences between the vitamin A supplemented and placebo groups from either trial in the prevalence of lifetime or current asthma and wheeze or in spirometric indices of obstruction ( p≥0.12 for all comparisons ) . Vitamin A supplementation early in life was not associated with a decreased risk of asthma  in an area with chronic vitamin A deficiency Previous studies of how parental  atopy and exposure to dampness and molds contribute to the risk of asthma  have been mainly cross-sectional or prevalent case – control studies , where selection and information bias and temporality constitute problems . We assessed longitudinally the independent and joint effects of  parental atopy and exposure to molds in dwellings on the development of asthma in childhood . We conducted a population -based , 6-year prospect i ve cohort study of 1,984 children 1–7 years of age at the baseline in 1991 ( follow-up rate , 77 % ) . The study population included 1,916 children without asthma at baseline and complete outcome information . The data collection included a baseline and follow-up survey . The outcome of interest was development of asthma during the study period . The studied determinants were parental allergic diseases and four indicators of exposure at baseline : histories of water damage , presence of moisture and visible molds , and perceived mold odor in the home . A total of 138 ( 7.2 % ) children developed asthma during the study period , result ing in an incidence rate of 125 cases per 10,000 person-years [ 95 % confidence interval ( CI ) , 104–146 ] . In Poisson regression adjusting for confounding , parental atopy [ adjusted incidence rate ratio ( IRR ) 1.52 ; 95 % CI , 1.08–2.13 ] and the presence of mold odor in the home reported at baseline ( adjusted IRR 2.44 ; 95 % CI , 1.07–5.60 ) were independent determinants of asthma incidence , but no apparent interaction was observed . The results of this cohort study with assessment of exposure before the onset of asthma strengthen the evidence on the independent effects of parental atopy and exposure to molds on the development of asthma RATIONALE Although epidemiological studies suggest that exposure to maternal smoking during fetal and early life increases the risk of  childhood wheezing and asthma  , previous studies were not able to differentiate the effects of prenatal from postnatal exposure . OBJECTIVES To assess the effect of exposure to maternal smoking only during pregnancy on  wheeze and asthma among preschool-age children . METHODS A pooled analysis was performed based on individual participant data from eight European birth cohorts . Cohort-specific effects of maternal smoking during pregnancy , but not during the first year , on wheeze and asthma at 4 to 6 years of age were estimated using logistic regression and then combined using a r and om effects model . Adjustments were made for sex , parental education , parental asthma , birth weight , and siblings . MEASUREMENTS AND MAIN RESULTS Among the 21,600 children included in the analysis , 735 children ( 3.4 % ) were exposed to maternal smoking exclusively during pregnancy but not in the first year after birth . In the pooled analysis , maternal smoking only during pregnancy was associated with wheeze and asthma at 4 to 6 years of age , with adjusted odds ratios of 1.39 ( 95 % confidence interval , 1.08 - 1.77 ) and 1.65 ( 95 % confidence interval , 1.18 - 2.31 ) , respectively . The likelihood to develop wheeze and asthma increased statistically significantly in a linear dose-dependent manner in relation to maternal daily cigarette consumption during the first trimester of pregnancy . CONCLUSIONS Maternal smoking during pregnancy appears to increase the risk of wheeze and asthma among children who are not exposed to maternal smoking after birth Background : Bisphenol A ( BPA ) , an endocrine-disrupting chemical that is routinely detected in > 90 % of Americans , promotes experimental asthma in mice . The association of prenatal BPA exposure and wheeze has not been evaluated in humans . Objective : We examined the relationship between prenatal BPA exposure and wheeze in early childhood . Methods : We measured BPA concentrations in serial maternal urine sample s from a prospect i ve birth cohort of 398 mother – infant pairs and assessed parent-reported child wheeze every 6 months for 3 years . We used generalized estimating equations with a logit link to evaluate the association of prenatal urinary BPA concentration with the dichotomous outcome wheeze ( wheeze over the previous 6 months ) . Results : Data were available for 365 children ; BPA was detected in 99 % of maternal urine sample s during pregnancy . In multivariable analysis , a one-unit increase in log-transformed creatinine-st and ardized mean prenatal urinary BPA concentration was not significantly associated with child wheeze from birth to 3 years of age , but there was an interaction of BPA concentration with time ( p = 0.003 ) . Mean prenatal BPA above versus below the median was positively associated with wheeze at 6 months of age [ adjusted odds ratio ( AOR ) = 2.3 ; 95 % confidence interval ( CI ) : 1.3 , 4.1 ] but not at 3 years ( AOR = 0.6 ; 95 % CI : 0.3 , 1.1 ) . In secondary analyses evaluating associations of each prenatal BPA concentration separately , urinary BPA concentrations measured at 16 weeks gestation were associated with wheeze ( AOR = 1.2 ; 95 % CI : 1.0 , 1.5 ) , but BPA concentrations at 26 weeks of gestation or at birth were not . Conclusions : Mean prenatal BPA was associated with increased odds of wheeze in early life , and the effect diminished over time . Evaluating exposure at each prenatal time point demonstrated an association between wheeze from 6 months to 3 years and log-transformed BPA concentration at 16 weeks gestation only BACKGROUND Bisphenol A ( BPA ) is used widely to manufacture food container linings . Mouse models suggest exposure to BPA might increase allergic inflammation . OBJECTIVES We hypothesized that BPA exposure , as assessed based on urinary BPA concentrations , would be associated with increased odds of wheeze and asthma  and increased fraction of exhaled nitric oxide ( Feno ) values in children . METHODS The Columbia Center for Children 's Environmental Health recruited pregnant women for a prospect i ve birth cohort study ( n = 568 ) . Mothers during the third trimester and children at ages 3 , 5 , and 7 years provided spot urine sample s. Total urinary BPA concentrations were measured by using online solid-phase extraction , high-performance liquid chromatography , isotope-dilution t and em mass spectrometry . Wheeze in the last 12 months was measured by using question naires at ages 5 , 6 , and 7 years . Asthma was determined by a physician once between ages 5 and 12 years . Feno values were measured at ages 7 to 11 years . RESULTS Prenatal urinary BPA concentrations were associated inversely with wheeze at age 5 years ( odds ratio [ OR ] , 0.7 ; 95 % CI , 0.5 - 0.9 ; P = .02 ) . Urinary BPA concentrations at age 3 years were associated positively with wheeze at ages 5 years ( OR , 1.4 ; 95 % CI , 1.1 - 1.8 ; P = .02 ) and 6 years ( OR , 1.4 ; 95 % CI , 1.0 - 1.9 ; P = .03 ) . BPA concentrations at age 7 years were associated with wheeze at age 7 years ( OR , 1.4 ; 95 % CI , 1.0 - 1.9 ; P = .04 ) and Feno values ( β = 0.1 ; 95 % CI , 0.02 - 0.2 ; P = .02 ) . BPA concentrations at ages 3 , 5 , and 7 years were associated with asthma ( OR , 1.5 [ 95 % CI , 1.1 - 2.0 ] , P = .005 ; OR , 1.4 [ 95 % CI , 1.0 - 1.9 ] , P = .03 ; and OR , 1.5 [ 95 % CI , 1.0 - 2.1 ] , P = .04 , respectively ) . CONCLUSIONS This is the first report of an association between postnatal urinary BPA concentrations and asthma in children The aim of our study was to examine the associations of breastfeeding duration and exclusiveness with the risks of asthma-related symptoms in preschool children , and to explore whether these associations are explained by atopic or infectious mechanisms . This study was embedded in a population -based prospect i ve cohort study of 5,368 children . Information on breastfeeding duration , exclusiveness and asthma-related symptoms , including wheezing , shortness of breath , dry cough and persistent phlegm , was obtained by question naires . Compared with children who were breastfed for 6 months , those who were never breastfed had overall increased risks of wheezing , shortness of breath , dry cough and persistent phlegm during the first 4 yrs ( OR 1.44 ( 95 % CI 1.24–1.66 ) , 1.26 ( 1.07–1.48 ) , 1.25 ( 1.08–1.44 ) and 1.57 ( 1.29–1.91 ) , respectively ) . Similar associations were observed for exclusive breastfeeding . The strongest associations per symptom per year were observed for wheezing at 1 and 2 yrs . Additionally adjusted analyses showed that the associations of breastfeeding with asthma-related symptoms were not explained by eczema but partly by lower respiratory tract infections . Shorter duration and nonexclusivity of breastfeeding were associated with increased risks of asthma-related symptoms in preschool children . These associations seemed , at least partly , to be explained by infectious , but not by atopic , mechanisms OBJECTIVE To investigate the incidence of  allergic and respiratory diseases  through age 3 years in children fed docosahexaenoic acid (DHA)- and arachidonic acid (ARA)-supplemented formula during infancy . STUDY DESIGN Children who completed r and omized , double-blind studies of DHA/ARA-supplemented  ( 0.32%-0.36%/0.64%-0.72 % of total fatty acids , respectively ) versus nonsupplemented ( control ) formulas , fed during the first year of life , were eligible . Blinded study nurses review ed medical charts for upper respiratory infection ( URI ) , wheezing , asthma , bronchiolitis , bronchitis , allergic rhinitis , allergic conjunctivitis , otitis media , sinusitis , atopic dermatitis ( AD ) , and urticaria . RESULTS From the 2 original cohorts , 89/179 children participated ; 38/89 were fed DHA/ARA formula . The DHA/ARA group had significantly lower odds for developing URI ( odds ratio [ OR ] , 0.22 ; 95 % confidence interval [ CI ] , 0.08 - 0.58 ) , wheezing/asthma ( OR , 0.32 ; 95 % CI , 0.11 - 0.97 ) , wheezing/asthma/AD ( OR , 0.25 ; 95 % CI , 0.09 - 0.67 ) , or any allergy ( OR , 0.28 ; 95 % CI , 0.10 - 0.72 ) . The control group had significantly shorter time to first diagnosis of URI ( P = .006 ) , wheezing/asthma ( P = .03 ) , or any allergy ( P = .006 ) . CONCLUSIONS DHA/ARA supplementation was associated with delayed onset and reduced incidence of URIs and common allergic diseases up to 3 years of age It is uncertain whether B group vitamins are risk or preventive factors for allergic disorders . We prospect ively investigated the association between maternal intake of folate and vitamins B(12 ) , B(6 ) , and B(2 ) during pregnancy and the risk of wheeze and eczema in the infants aged 16 - 24 months . Subjects were 763 Japanese mother-child pairs . Data on maternal intake during pregnancy were assessed with a  diet history question naire ( DHQ ) . Symptoms of wheeze and eczema were based on criteria of the International Study of Asthma and Allergies in Childhood . Among 763 infants , 169 ( 22.1 % ) and 142 ( 18.6 % ) had symptoms of wheeze and eczema  , respectively . There were no evident relationships between maternal consumption  of folate , vitamin B(12 ) , vitamin B(6 ) , and vitamin B(2 ) during pregnancy and the risk of wheeze or eczema in the offspring after adjustment for maternal age , gestation at baseline , residential municipality at baseline , family income , maternal and paternal education , maternal and paternal history of asthma , atopic eczema , and allergic rhinitis , changes in maternal diet in the previous 1 month , season when data at baseline were collected , maternal smoking during pregnancy , baby 's older siblings , baby 's sex , baby 's birth weight , household smoking in the same room as the infant , breastfeeding duration , age at which solid foods were introduced , age of infant at the third survey , and maternal intake of docosahexaenoic acid , n-6 polyunsaturated fatty acids , vitamin D , calcium , vitamin E , and β-carotene during pregnancy . Further investigation is warranted to draw conclusions as to the question of whether maternal B vitamin intake during pregnancy is related to the risk of childhood allergic disorders RATIONALE Air pollution is a known asthma trigger and has been associated with short-term asthma symptoms , airway inflammation , decreased lung function , and reduced response to asthma rescue medications . OBJECTIVES To assess a causal relationship between air pollution and childhood asthma using data that address temporality by estimating air pollution exposures before the development of asthma and to establish the generalizability of the association by study ing diverse racial/ethnic population s in different geographic regions . METHODS This study included Latino ( n = 3,343 ) and African American ( n = 977 ) participants with and without asthma from five urban regions in the mainl and United States and Puerto Rico .  Residential history and data from local ambient air monitoring stations were used to estimate average annual exposure to five air pollutants : ozone , nitrogen dioxide ( NO₂ ) , sulfur dioxide , particulate matter not greater than 10 μm in diameter , and particulate matter not greater than 2.5 μm in diameter . Within each region , we performed logistic regression to determine the relationship between early-life exposure to air pollutants and subsequent asthma diagnosis . A r and om-effects model was used to combine the region-specific effects and generate summary odds ratios for each pollutant . MEASUREMENTS AND MAIN RESULTS After adjustment for confounders , a 5-ppb increase in average NO₂ during the first year of life was associated with an odds ratio of 1.17 for physician-diagnosed asthma ( 95 % confidence interval , 1.04 - 1.31 ) . CONCLUSIONS Early-life NO₂ exposure is associated with childhood asthma in Latinos and African Americans . These results add to a growing body of evidence that traffic-related pollutants may be causally related to childhood asthma Background : Environment and lifestyle contribute to the development of asthma in children . Underst and ing the relevant factors in this relationship may provide methods of prevention . The role of diet in the development of asthma in pre-school children was investigated . Methods : Data from 2978 children participating in a prospect i ve birth cohort study were used . Food frequency data were collected at the age of 2 years and related to asthma symptoms reported at the age of 3 years . Results : The prevalence of recent asthma at age 3 was lower in children who consumed ( at age 2 ) full cream milk daily ( 3.4 % ) than in those who did not ( 5.6 % ) and in those who consumed butter daily ( 1.5 % ) than in those who did not ( 5.1 % ) . The prevalence of recent wheeze was lower in children who consumed milk products daily ( 13.7 % ) than in those who did not ( 18.4 % ) and in children who consumed butter daily ( 7.7 % ) than in those who did not ( 15.4 % ) . These effects remained in a logistic regression model including different foods and confounders ( adjusted odds ratio ( CI ) for recent asthma : full cream milk daily v rarely 0.59 ( 0.40 to 0.88 ) , butter daily v rarely 0.28 ( 0.09 to 0.88 ) ) . Daily consumption of brown bread was also associated with lower rates of asthma and wheeze , whereas no associations were observed with the consumption of fruits , vegetables , margarine , and fish . Conclusions : In pre-school children , frequent consumption of products containing milk fat is associated with a reduced risk of asthma symptoms BACKGROUND Cat ownership is inversely associated with  atopy and asthma in some areas of the world , but the relevance of cat ownership to allergic disease in the inner city is less known . OBJECTIVE We sought to evaluate the relationship between cat ownership and the development of early sensitization and wheeze .  METHODS By using a prospect i ve birth cohort study , Dominican and African American mothers living in New York City underwent repeated question naires about their child from birth to age 5 years . Sera collected from children at ages 2 ( n = 323 ) , 3 ( n = 336 ) , and 5 ( n = 242 ) years were assayed for anti-cat IgE and anti-Fel d 1 IgG antibodies . RESULTS Cat ownership was a significant risk factor for the development of anti-cat IgE by age 2 years ( risk ratio [ RR ] , 6.4 ; 95 % CI , 1.9 - 22 ) but not for anti-cat IgE development between the ages of 2 and 5 years ( RR , 0.88 ; 95 % CI , 0.24 - 2.3 ) . Current wheeze was significantly more common among those children with anti-cat IgE at ages 3 ( RR , 3.5 ; 95 % CI , 2.1 - 6.0 ) and 5 ( RR , 3.4 ; 95 % CI , 2.3 - 4.9 ) years . Cat ownership was inversely associated with current wheeze at age 5 years among children without anti-cat IgE ( RR , 0.26 ; 95 % CI , 0.083 - 0.81 ) . Among children with anti-cat IgE , a similar trend was observed ( RR , 0.57 ; P = .044 , Fisher exact test ) , although one with borderline statistical significance . CONCLUSIONS Despite a positive association with sensitization , cat ownership in this inner-city cohort was inversely associated with wheeze , potentially suggesting an IgE-independent protective mechanism in this community RATIONALE Daycare exposes young children to more infections early in life and may thereby prevent the development of  asthma and allergy . OBJECTIVES To prospect ively study the effect of daycare on the development of  asthma and allergic sensitization during the first 8 years of life . METHODS In the Prevention and Incidence of Asthma and Mite Allergy birth cohort 3,963 newborn children were followed prospect ively for 8 years . Daycare use and respiratory health were assessed yearly by question naires . At 8 years , sensitization to airborne allergens and airway responsiveness were measured . Daycare was defined as early ( aged 0 - 2 yr ) , late ( aged 2 - 4 yr ) , or none ( no daycare before age 4 yr ) . Associations of daycare and /or older siblings with asthma symptoms ( wheezing , shortness of breath , and inhaled steroids taken in the last year ) , airway responsiveness , and allergic sensitization were assessed in a longitudinal repeated-event analysis . MEASUREMENTS AND MAIN RESULTS Children with early daycare  had more wheezing in the first years of life , but less wheezing and steroid use between 4 and 8 years of age . At the age of 8 years , early daycare was not protective for asthma symptoms ( adjusted odds ratio [ aOR ] , 0.99 ; 95 % confidence interval [ CI ] , 0.74 - 1.32 ) , allergic sensitization ( aOR 0.86 ; 95 % CI , 0.63 - 1.18 ) , or airway hyperresponsiveness ( aOR , 0.80 ; 95 % CI , 0.57 - 1.14 ) . The transient reduction in airway symptoms between age 4 and 8 years was only observed in children without older siblings . CONCLUSION Early daycare is associated with an increase in airway symptoms until the age of 4 years , and fewer symptoms between the ages of 4 and 8 years . We found no protection against asthma symptoms , hyperresponsiveness , or allergic sensitization at the age of 8 years BACKGROUND Epidemiologic studies show statistical associations between levels of air pollutants and respiratory outcomes . OBJECTIVE We sought to determine the effects of exposure to petrochemical pollution on the  respiratory health of children . METHODS Children aged 6 to 12 years living close to the petrochemical plants in La Plata , Argentina ( n = 282 ) , were compared with those living in a region with exposure to heavy traffic ( n = 270 ) or in 2 relatively nonpolluted areas ( n = 639 ) . Parents answered a vali date d question naire providing health and demographic data . A r and om sample ( n = 181 ) had lung function measured . Particulate matter and outdoor and indoor volatile organic compound levels were measured during 4-week study periods and reported as overall means for each study area . RESULTS Children living near the petrochemical plant had more asthma ( 24.8 % vs 10.1 % to 11.5 % ) , more asthma exacerbations ( 6.7 vs 2.9 - 3.6 per year ) , more respiratory symptoms ( current wheeze , dyspnea , nocturnal cough , and rhinitis ) , and lower lung function ( > 13 % decrease in FEV(1 ) percent predicted ) than those living in other regions . Length of residence in the area was a significant risk factor , but age , sex , body mass index , proximity to busy roads and other nonpetrochemical industries , length of breast-feeding , and socioeconomic and demographic characteristics of children or their families were not . CONCLUSION Exposure to particulate matter and volatile organic compounds arising from petrochemical plants but not from high traffic density was associated ith worse respiratory health in children OBJECTIVE The objective of the study was to assess whether folic acid intake during the first trimester of pregnancy is related to  asthma in the offspring by the age of 6 years . STUDY DESIGN This was a prospect i ve cohort study of 1499 women who were followed up from the first trimester of pregnancy . Their children were followed up until they were 6 years old . RESULTS Fifty-one percent of the women used folic acid in the month before conception and 88 % in the third month of pregnancy . The adjusted odds ratio for asthma per 100 μm increase in the average daily intake of folic acid was 0.98 ( 95 % confidence interval , 0.93 - 1.04 ) . For categories of daily folate intake , there was no evidence of associations with childhood asthma or evidence of any dose response relation for any time period ( all P(trend ) > .05 ) . CONCLUSION Our results do not support any association of folic acid supplementation in pregnancy and asthma risk in offspring by age 6 years To examine whether long-term consumption of fermented milk containing a specific Lactobacillus casei may improve the health status of preschool children suffering from allergic asthma and /or rhinitis a r and omized , prospect i ve , double blind , controlled trial was conducted in 187 children 2–5 y of age . The children received for 12 mo either fermented milk ( 100 mL ) containing Lactobacillus casei ( 108 cfu/mL ) or placebo . The time free from and the number of episodes of asthma/rhinitis after starting intervention were the outcome measures . The number of fever or diarrhea episodes and the change in serum immunoglobulin were further assessed . No statistical difference between intervention and control group occurred in asthmatic children . In children with rhinitis , the annual number of rhinitis episodes was lower in the intervention group , mean difference ( 95 % CI ) , −1.6 ( −3.15 to −0.05 ) ; the mean duration of an episode of diarrhea was lower in the intervention group , mean difference −0.81 ( −1.52 to −0.10 ) days . While long-term consumption of fermented milk containing Lactobacillus casei may improve the health status of children with allergic rhinitis no effect was found in asthmatic children OBJECTIVE To examine whether the timing of introduction of the allergenic foods cow 's milk , hen 's egg , peanuts , tree nuts , soy , and gluten is associated with  eczema and wheezing in children 4 years of age or younger . DESIGN Population -based prospect i ve cohort study from fetal life until young adulthood . SETTING Rotterdam , the Netherl and s , from April 2002 through January 2006 . PARTICIPANTS A total of 6905 preschool children participating in the Generation R study . MAIN EXPOSURE Timing of introduction of cow 's milk , hen 's egg , peanuts , tree nuts , soy , and gluten collected by question naires at 6 and 12 months of age . MAIN OUTCOME MEASURES Information on the outcomes eczema and wheezing were obtained by questions from the age-adapted version of the " International Study of Asthma and Allergies in Childhood " core question naire and question naire data on parentally reported physician diagnosis for eczema . RESULTS Of 6905 children ,  wheezing was reported in 31 % at age 2 years and in 14 % at ages 3 and 4 years . Eczema was reported in 38 % , 20 % , and 18 % of children at the ages of 2 , 3 , and 4 years , respectively . The introduction of cow 's milk , hen 's egg , peanuts , tree nuts , soy , and gluten before the age of 6 months was not significantly associated with eczema or wheezing at any age after adjustment for potential confounders ( P > .10 for all comparisons ) . The results did not alter after stratification according to the child 's history of cow 's milk allergy and parental history of atopy . CONCLUSION This study does not support the recommendation for delayed introduction of allergenic foods after age 6 months for the prevention of eczema and wheezing BACKGROUND Earlier studies have reported an increased risk of asthma  after respiratory syncytial virus ( RSV ) hospitalization . Other studies found that asthmatic disposition and propensity to wheeze increase the risk of RSV hospitalization . OBJECTIVE The current study examined the causal direction of the associations between RSV hospitalization and asthma in a population -based cohort of twins . METHODS We conducted a prospect i ve cohort study examining the associations between RSV hospitalization and asthma by using registry information on RSV hospitalization and asthma among 18,614 Danish twins born 1994 to 2003 . The associations between RSV and asthma were examined in both directions : we examined the risk of asthma after RSV hospitalization , and the risk of  RSV hospitalization  in children with asthma in the same population -based cohort . RESULTS Asthma hospitalization after RSV hospitalization was increased as much as 6-fold to 8-fold during the first 2 months after RSV hospitalization but was no longer increased 1 year later . Asthma increased the risk of RSV hospitalization by 3-fold , and the risk was not time-dependent . Analyzing these associations on the basis of asthma defined from use of inhaled corticosteroid did not material ly change the risk estimates . CONCLUSION There is a bidirectional association between severe RSV infection and asthma . Severe RSV infection is associated with a short-term increase in the risk of subsequent asthma , suggesting that RSV induce bronchial hyperresponsiveness ; and asthma is associated with a long-term increased susceptibility for severe RSV disease , suggesting a host factor being responsible for the severe response to RSV infection . This suggests that severe RSV infection and asthma may share a common genetic predisposition and /or environmental exposure BACKGROUND The relationship between mite and pet allergen exposure in infancy and the subsequent development of sensitization and asthma is complex . OBJECTIVE We prospect ively investigated the effect of allergen exposure at 3 months of age on the development of sensitization , wheeze , and physician-diagnosed asthma in the first 4 years of life in a birth cohort of children with and without an atopic mother . METHODS Children participated in the Prevention and Incidence of Asthma and Mite Allergy study .  Allergen exposure at 3 months of age was determined from mattress dust sample s. Specific IgE to inhalant allergens was measured at 4 years of age , and information about wheeze and physician-diagnosed asthma was collected with yearly question naires . RESULTS Mite and cat allergen exposure in infancy were associated with an increased risk of specific sensitization to house dust mite and cat , respectively , at 4 years of age . There were borderline significant associations between cat allergen exposure and persistent wheeze in the total study population and between dog allergen exposure and persistent wheeze in children with a nonatopic mother . In children with an atopic mother , there was some indication of a positive association between mite allergen exposure and physician-diagnosed asthma . CONCLUSION Early house dust mite and cat allergen exposure might lead to sensitization and , in case of cat allergen exposure , to persistent wheeze . Early mite and dog allergen exposure might lead to asthma and persistent wheeze , respectively , but only in subgroups defined by maternal atopy The evidence of the effect of the age at introduction of new foods during infancy on the development of  asthma and allergic rhinitis  is inconsistent and scarce . We set out to study these associations . A prospect i ve birth cohort of infants with increased HLA-DQB1-conferred risk for type 1 diabetes was recruited in 1996 - 2000 . The families completed at home a record on the age at introduction of new foods .  Persistent asthma and allergic rhinitis were assessed at the age of 5 years with an International Study of Asthma and Allergies in Childhood-type question naire . The Cox proportional hazards regression analyses were adjusted for parental asthma and allergic diseases , and several perinatal and sociodemographical factors . Out of the 1293 children , 77 ( 6.0 % ) developed  persistent asthma ; and out of the 1288 children , 185 ( 14.4 % ) developed allergic rhinitis by the age of 5 years . Early age at introduction of oats was associated with a reduced risk of persistent asthma ( hazard ratio ( HR ; 95 % CI ) for the first and mid-tertiles compared with the latest tertile was 0.36 ( 0.15 , 0.85 ) and 0.37 ( 0.22 , 0.62 ) , respectively , P < 0.001 ) . Early age at introduction of fish was dose dependently associated with a decreased risk of allergic rhinitis ( HR ( 95 % CI ) for the first and mid-tertiles compared with the latest tertile was 0.34 ( 0.22 , 0.54 ) and 0.45 ( 0.28 , 0.70 ) , respectively , P < 0.001 ) . The present finding that age at introduction of oats is inversely and independently associated with development of persistent asthma is novel . We confirmed the earlier observation that the age at introduction of fish is inversely related to the risk of allergic rhinitis . Clinical implication s remain to be determined We prospect ively investigated whether organic food consumption by infants was associated with developing atopic manifestations in the first 2 years of life . The KOALA Birth Cohort Study in the Netherl and s ( n 2764 ) measured organic food consumption ,  eczema and wheeze in infants until age 2 years using repeated question naires . Diet was defined as conventional ( 90 % organic ) . Venous blood sample s taken from 815 infants at 2 years of age were analysed for total and specific IgE. Multivariate logistic regression models were fitted to control for potential confounding factors . Eczema was present in 32 % of infants , recurrent wheeze in 11 % and prolonged wheezing in 5 % . At 2 years of age , 27 % of children were sensitised against at least one allergen . Of all the children , 10 % had consumed a moderately organic diet and 6 % a strictly organic diet . Consumption of organic dairy products was associated with lower eczema risk ( OR 0.64 ( 95 % CI 0.44 , 0.93 ) ) , but there was no association of organic meat , fruit , vegetables or eggs , or the proportion of organic products within the total diet with the development of eczema , wheeze or atopic sensitisation . Further studies to substantiate these results are warranted BACKGROUND Although the effectiveness of the multifaceted allergen-reducing interventions for the prevention of asthma in susceptible children was showed to be proven , the feasibility was not clear . METHODS The research question of the PREVention of asthma in susceptible children ( PREVASC ) trial was focused on the assessment of the effectiveness and feasibility of a multifaceted intervention on the prevention of allergic asthma in general practice . The effectiveness and feasibility of an intervention aim ed at the simultaneous reduction in the environmental exposures to inhalant- and food allergens in susceptible children was investigated . A total of 476 children susceptible for developing asthma were initially included during pregnancy and were r and omly divided over an intervention group of n = 222 children whose parents were offered a multifaceted environmental exposure-reducing intervention . Controls ( n = 221 ) received usual care . The main outcome was ' diagnosis of allergic asthma at age 6 ' . RESULTS A significant reduction in inhalant allergen exposure levels of house dust mite [ ( Der p1 ) , p = 0.043 ] , cat [ ( Fel d1 ) , p = 0.037 ] , and dog [ ( Can f1 ) , p = 0.012 ] was reached . Significantly more intervention group children started using cow 's milk and solids after the age of 6 months ( p ≤ 0.001 ) . No statistical difference , however , was reached between groups on the duration of breast-feeding ( p = 0.635 ) and the reduction in smoke exposure ( p = 0829 ) . At age 6 , the intervention had no influence on the development of main outcome allergic asthma ( OR = 1.010 ( CI 0.580 - 1.758 ) . CONCLUSION Other primary preventive asthma-reducing interventions were shown to be effective in reducing the occurrence of asthma for at least the first 7 - 8 yr of life . The multifaceted PREVASC allergic asthma primary preventive intervention was effective in reducing the exposure to inhalant and food allergens , but was not feasible for the parents . A lack of sufficient room for improvement focus on stimulating adherence seemed to be involved . It is suggested that a multifaceted environmental exposure-reducing intervention may have to be adapted to the personal circumstances of patients at baseline Background / Objectives : To determine the impact of a not hydrolyzed fermented infant formula containing heat-killed Bifidobacterium breve C50 and Streptococcus thermophilus 065 ( HKBBST ) on the incidence of allergy-like events during the first 2 years of life in children at high risk of atopy . Subjects/ Methods : This multicenter , r and omized , double-blind , controlled study included infants at high risk of atopy . Infants used HKBBST or a st and ard infant formula ( SIF ) since birth until 1 year of age , and were followed at 4 , 12 and 24 months after birth .  Skin prick tests ( SPTs ) for six foods and six aeroallergens were systematic ally performed and adverse events ( AEs ) were recorded . In case of potentially allergic AE ( PAAE ) , allergy could be further tested by SPT , patch tests and quantification of specific IgEs . If cow 's milk allergy ( CMA ) was suspected , an oral challenge could also be performed . Results : The study included 129 children , 63 were r and omized to SIF , 66 to HKBBST . The use of HKBBST milk did not alter the proportion of CMA but decreased the proportion of positive SPT to cow 's milk ( 1.7 vs 12.5 % , P=0.03 ) , and the incidence of digestive ( 39 vs 63 % , P=0.01 ) and respiratory potentially allergic AEs ( 7 vs 21 % , P=0.03 ) at 12 months , and that of respiratory PAAEs at 24 months ( 13 vs 35 % , P=0.01 ) . Conclusions : HKBBST decreased the incidence of PAAEs in children with family history of atopy , during the first months of life and after the formula was stopped . Oral tolerance to cow 's milk in infants at high risk of atopy may therefore be improved using not hydrolyzed fermented formulae RATIONALE Although it is widely assumed that the incidence of childhood respiratory allergies to common aeroallergens is directly related to allergen exposure in early life , few longitudinal studies have investigated this issue , and available data are scarce and mainly limited to high-risk groups . OBJECTIVES To assess , in a prospect i ve manner and in a general population , the role of early life exposures to Der p1 and Fel d1 on the inception of sensitization and asthma . METHODS Pregnant women and their children were recruited for the Asthma Multicentre Infant Cohort Study . Overall , 1,611 newborns were initially enrolled in three cohorts in the United Kingdom and Spain .  Der p1 and Fel d1 allergens were measured in household dust sample s at 3 months of age for 1,474 ( 91.5 % ) participants , and skin prick tests were performed at 6 years of age on 1,182 ( 80.2 % ) participants . Wheeze and diagnosed asthma were reported in yearly question naires . MEASUREMENTS AND MAIN RESULTS Exposure to Der p1 early in life was not related to a positive specific prick test or to asthma or persistent wheeze at 6 years of age . Fel d1 showed an association with all these outcomes ( third vs. first tertile ; odds ratio , 4.43 for positive specific prick test and 2.6 for diagnosed asthma ) . CONCLUSIONS Dose-response relationships between allergen exposure and sensitization or asthma may be allergen specific and nonlinear ; a minimum threshold level is needed to induce sensitization , but no dose-response relationship exists above this level . The effect of a particular allergen seems to be similar on atopy and asthma inception Background : Exposure to cow ’s milk protein in early infancy could lead to increased rates of allergic diseases later in life . We investigated whether feeding a protein-hydrolyzed formula ( HF ) in the first 6 months of life decreased allergic diseases up to 36 months later . Methods : Newborns who had at least 1 first-degree family member with a history of atopy and could not breast-feed were enrolled . They were fed with HF or cow ’s milk infant formula ( CM ) for at least 6 months via an open-label protocol and were monitored prospect ively at 6 , 18 and 36 months of age to assess allergy sensitization and allergic diseases . Results : A total of 1,002 infants were enrolled and 679 infants were consistently fed the same formula for the first 6 months of life ( 345 HF and 334 CM ) . The percentage of food sensitization ( especially to milk protein ) was significantly lower in the HF group than in the CM group at 36 months ( 12.7 vs. 23.4 % , p = 0.048 ) . There was no significant difference in the prevalence of aeroallergen sensitization between the groups . Occurrence of allergic diseases during the first 3 years of life was significantly correlated with aeroallergen sensitization , but not to food allergen sensitization , parental atopy or feeding types . Conclusions : Infants fed with HF during the first 6 months of life had a significantly lower percentage of sensitization to milk protein allergens , but not allergic diseases during the first 3 years of life . Avoidance of cow ’s milk protein alone in infancy is not enough to decrease rates of allergic diseases BACKGROUND Prenatal maternal smoking and prematurity independently affect  wheezing and asthma in childhood . OBJECTIVE We sought to evaluate the interactive effects of maternal smoking and prematurity upon the development of  early childhood wheezing . METHODS We evaluated 1,448 children with smoke exposure data from a prospect i ve urban birth cohort in Boston .  Maternal antenatal and postnatal exposure was determined from st and ardized question naires . Gestational age was assessed by the first day of the last menstrual period and early prenatal ultrasound ( preterm < 37 weeks gestation ) . Wheezing episodes were determined from medical record extraction of well and ill/unscheduled visits . The primary outcome was recurrent wheezing , defined as ≥ 4 episodes of physician documented wheezing . Logistic regression models and zero inflated negative binomial regression ( for number of episodes of wheeze ) assessed the independent and joint association of prematurity and maternal antenatal smoking on recurrent wheeze , controlling for relevant covariates . RESULTS In the cohort , 90 ( 6 % ) children had recurrent wheezing , 147 ( 10 % ) were exposed to in utero maternal smoke and 419 ( 29 % ) were premature . Prematurity ( odds ratio [ OR ] 2.0 ; 95 % confidence interval [ CI ] , 1.3 - 3.1 ) was associated with an increased risk of recurrent wheezing , but in utero maternal smoking was not ( OR 1.1 , 95 % CI 0.5 - 2.4 ) . Jointly , maternal smoke exposure and prematurity caused an increased risk of recurrent wheezing ( OR 3.8 , 95 % CI 1.8 - 8.0 ) . There was an interaction between prematurity and maternal smoking upon episodes of wheezing ( P = 0.049 ) . CONCLUSIONS We demonstrated an interaction between maternal smoking during pregnancy and prematurity on childhood wheezing  in this urban , multiethnic birth cohort We investigated whether environmental control during pregnancy and early life affects sensitization and lung function at the age of 3 years . High-risk children ( n = 251 ) were prenatally r and omized to stringent environmental control ( active ) or no intervention ( control ) . Question naires , skin testing , IgE , and specific airway resistance ( sRaw ) measurement were completed at the age of 3 years . Children in the active group were significantly more frequently sensitized compared with control subjects ( at least one allergen by skin tests : risk ratio , 1.61 ; 95 % confidence interval [ CI ] , 1.02 - 2.55 ; p = 0.04 ; mite by IgE : risk ratio , 2.85 ; 95 % CI , 1.02 - 7.97 ; p = 0.05 ) . However , sRaw was significantly better in the active group ( kiloPascal/second , geometric mean [ 95 % CI ] : 1.05 [ 1.01 - 1.10 ] vs. 1.19 [ 1.13 - 1.25 ] , p < 0.0001 , active vs. control ) . Maximal flow at functional residual capacity was measured using rapid thoracic compression at the age of 4 weeks in a subgroup . Prospect i ve lung function data ( at infancy and 3 years ) were obtained in 32 children ( 14 active and 18 control ) . There was no difference in infant lung function between the groups , but at 3 years , sRaw was significantly lower in the active compared with control children ( p = 0.003 ) . Stringent environmental control was associated with increased risk of mite sensitization but better results for some measurements of lung function in high-risk children at the age of 3 years Purpose . It remains controversial whether environmental tobacco smoke increases the risk of allergic diseases . The present prospect i ve cohort study examined whether in utero exposure to maternal smoking and postnatal exposure to environmental tobacco smoke were associated with the development of  wheeze , asthma , and atopic eczema in Japanese infants . Methods . Study subjects included 763 infants . Data were obtained through the use of question naires completed by the mother during pregnancy and at 2 to 9 and 16 to 24 months postdelivery . Information regarding maternal smoking during pregnancy and postnatal exposure to environmental tobacco smoke was collected at 2 to 9 months postdelivery , and information on allergic symptoms was collected when the infant was between 16 to 24 months of age . Cases were defined according to criteria of the International Study of Asthma and Allergies in Childhood for wheeze and atopic eczema . Additionally , doctor-diagnosed asthma and atopic eczema were identified . Adjustment was made for maternal age , family income , maternal and paternal education , parental history of asthma , atopic eczema , allergic rhinitis , indoor domestic pets , baby 's older siblings , baby 's sex , birth weight , and time of surveys . Results . The cumulative incidence of wheeze , atopic eczema , doctor-diagnosed asthma , and doctor-diagnosed atopic eczema was 22.1 % , 18.6 % , 4.3 % , and 9.0 % , respectively . Maternal smoking during pregnancy was not related to the risk of wheeze , whereas postnatal maternal smoking in the same room as the child increased the risk of wheeze . No significant association was observed between perinatal tobacco smoke exposure and the development of asthma and atopic eczema . Conclusions . Our findings suggest that postnatal maternal smoking might be associated with an increased risk of wheeze in Japanese infants BACKGROUND Early life allergen exposure may increase the risk of childhood allergy , but the protective effect of reduction in allergen exposure remains uncertain . OBJECTIVE To evaluate the effect of reduction in food and house dust mite ( HDM ) allergen exposure in infancy in preventing asthma and allergy . METHODS Infants , at higher risk because of family predisposition , were recruited prenatally and r and omized to prophylactic ( n = 58 ) and control ( n = 62 ) groups . Prophylactic group infants were either breast-fed with mother on a low allergen diet or given an extensively hydrolyzed formula . Exposure to HDM was reduced by the use of an acaricide and mattress covers . The control group followed st and ard advice .  Development of allergic diseases and sensitization to common allergens ( atopy ) was assessed blindly at ages 1 , 2 , 4 , and 8 years in all 120 children . RESULTS Repeated measurement analysis , adjusted for all relevant confounding variables , confirmed a preventive effect on asthma : adjusted odds ratio ( OR ) , 0.24 ; 95 % CI , 0.09 - 0.66 ; P = .005 ; atopic dermatitis , OR , 0.23 ; CI , 0.08 - 0.64 ; P = .005 ; rhinitis , OR , 0.42 ; CI , 0.19 - 0.92 ; P = .03 ; and atopy , OR , 0.13 ; CI , 0.05 - 0.32 ; P < .001 . The protective effect was primarily observed in the subgroup of children with persistent disease ( symptoms at all visits ) and in those with evidence of allergic sensitization . CONCLUSION Allergic diseases can be reduced , for at least the first 8 years of life , by combined food and HDM allergen avoidance in infancy . CLINICAL IMPLICATION S Strict food and HDM allergen avoidance should be considered for prevention of allergy in high-risk infants BACKGROUND Early life exposures may be important in the development of asthma and allergic disease . OBJECTIVE To test house dust mite ( HDM ) avoidance and dietary fatty acid modification , implemented throughout the first 5 years of life , as interventions to prevent asthma and allergic disease . METHODS We recruited newborns with a family history of asthma antenatally and r and omized them , separately , to HDM avoidance or control and to dietary modification or control . At age 5 years , they were assessed for asthma and eczema and had skin prick tests for atopy . RESULTS Of 616 children r and omized , 516 ( 84 % ) were evaluated at age 5 years . The HDM avoidance intervention result ed in a 61 % reduction in HDM allergen concentrations ( microg/g dust ) in the child 's bed but no difference in the prevalence of asthma , wheeze , or atopy ( P > .1 ) . The prevalence of eczema was higher in the active HDM avoidance group ( 26 % vs 19 % ; P = .06 ) . The ratio of omega-6 to omega-3 fatty acids in plasma was lower in the active diet group ( 5.8 vs 7.4 ; P < .0001 ) . However , the prevalence of asthma , wheezing , eczema , or atopy did not differ between the diet groups ( P > .1 ) . CONCLUSION Further research is required to establish whether other interventions can be recommended for the prevention of asthma and allergic disease . CLINICAL IMPLICATION S House dust mite avoidance measures and dietary fatty acid modification , as implemented in this trial during infancy and early childhood , did not prevent the onset of asthma , eczema , or atopy in high-risk children OBJECTIVE To determine whether maternal exposure to high levels of magnetic fields ( MFs ) during pregnancy is associated with the  risk of asthma in offspring . DESIGN A prospect i ve cohort study . SETTING Kaiser Permanente Northern California . PARTICIPANTS Pregnant Kaiser Permanente Northern California members in the San Francisco area . MAIN OUTCOME MEASURES Asthma was clinical ly diagnosed among 626 children who were followed up for as long as 13 years . All participants carried a meter to measure their MF levels during pregnancy . RESULTS After adjustment for potential confounders , a statistically significant linear dose-response relationship was observed between increasing maternal median daily MF exposure level in pregnancy and an increased risk of asthma in offspring : every 1-mG increase of maternal MF level during pregnancy was associated with a 15 % increased rate of asthma in offspring ( adjusted hazard ratio [ aHR ] , 1.15 ; 95 % confidence interval [ CI ] , 1.04 - 1.27 ) . Using the categorical MF level , the results showed a similar dose-response relationship : compared with the children whose mothers had a low MF level ( median 24-hour MF level , ≤0.3 mG ) during pregnancy , children whose mothers had a high MF level ( > 2.0 mG ) had more than a 3.5-fold increased rate of asthma ( aHR , 3.52 ; 95 % CI , 1.68 - 7.35 ) , while children whose mothers had a medium MF level ( > 0.3 - 2.0 mG ) had a 74 % increased rate of asthma ( aHR , 1.74 ; 95 % CI , 0.93 - 3.25 ) . A statistically significant synergistic interaction was observed between the MF effect and a maternal history of asthma and birth order ( firstborn ) . CONCLUSION Our findings provide new epidemiological evidence that high maternal MF levels in pregnancy may increase the risk of asthma in offspring OBJECTIVES We investigated the role of  infant bedding items , as part of a composite bedding environment , in the development of  childhood wheezing .  METHODS This prospect i ve cohort investigation involved 863 children who participated in an infant survey in 1988 and an asthma study in Tasmania , Australia , in 1995 . The derived 3 composite infant bedding categories corresponded to increasing numbers of house dust mite (HDM)-rich bedding items used . Outcomes measured included recent and frequent wheezing . RESULTS Composite infant bedding used was associated with recent wheezing . Effects increased at increasing levels of HDM-rich bedding items used . Effects were further enhanced by home environmental factors of bedroom heating , recent bedroom painting , and absence of bedroom carpeting . When any 2 or more of these environmental factors were present , a strong dose-response relationship was evident . CONCLUSIONS Our results show that bedding exposures in infancy are prospect ively associated with  childhood wheezing  and that home environmental conditions may modify this association Swimming pool attendance and exposure to chlorination by-products showed adverse health effects on children . We assessed whether early swimming pool attendance , especially baby swimming , is related to higher rates of early infections and to the development of allergic diseases .  In 2003 - 2005 , 2192 children were analysed for the 6-year follow-up of a prospect i ve birth cohort study . Data on early swimming pool attendance , other lifestyle factors and medical history were collected by parental-administered question naire . Bivariate and multivariate logistic regression analyses were used to evaluate associations . Babies who did not participate in baby swimming had lower rates of infection in the 1st year of life ( i ) diarrhoea : OR 0.68 CI 95 % 0.54 - 0.85 ; ( ii ) otitis media : OR 0.81 CI 95 % 0.62 - 1.05 ; ( iii ) airway infections : OR 0.85 CI 95 % 0.67 - 1.09 . No clear association could be found between late or non-swimmers and atopic dermatitis or hay fever until the age of 6 years , while higher rates of asthma were found ( OR 2.15 95 % CI 1.16 - 3.99 ) , however , potentially due to reverse causation . The study indicates that , in terms of infections , baby swimming might not be as harmless as commonly thought . Further evidence is needed to make conclusions if the current regulations on chlorine in Germany might not protect swimming pool attendees from an increased risk of gastrointestinal infections . In terms of developing atopic diseases there is no verifiable detrimental effect of early swimming Background : Recall bias may provide discrepant relationships of pet exposure with  sensitization and asthma development . We studied prospect ively effects of  pets at home on development of sensitization , asthma and respiratory symptoms from birth up to age 8 years BACKGROUND Research suggests an influence of micronutrients on  childhood asthma .  So far , evidence mainly originates from cross-sectional studies using nutrient intake data , which is not an accurate measure of nutrient status . This study aim ed to investigate the cross-sectional and prospect i ve associations between serum concentrations of magnesium , vitamin D , selenium , and zinc and prevalence of ( severe ) asthma , atopy , and bronchial hyperresponsiveness ( BHR ) in childhood . METHODS In the Prevention and Incidence of Asthma and Mite Allergy birth cohort study , serum nutrient concentrations were available for a 4-yr-old subgroup ( n = 372 ) and for a different 8-yr-old subgroup ( n = 328 ) . Yearly question naires inquired about asthma prevalence until 8 yr of age . Allergic sensitization was measured at 4 and 8 yr of age ; BHR was measured at 8 yr of age . Data were analyzed with logistic regression and generalized estimating equations models . RESULTS There was a consistent ( non-significant ) inverse association between serum magnesium concentrations and asthma prevalence . Serum vitamin D concentrations measured at age 4 were inversely associated with asthma at ages 4 - 8 [ e.g. , cross-sectional association between vitamin D tertile 3 vs. 1 and severe asthma : odds ratio ( OR ) : 0.49 , 95 % confidence interval ( CI ) : 0.25 - 0.95 ] , whereas vitamin D measured at age 8 was positively associated with asthma at age 8 ( e.g. , cross-sectional association between vitamin D tertile 3 vs. 1 and severe asthma : OR : 2.14 , 95 % CI : 0.67 - 6.82 ) . CONCLUSIONS Our study contributes to the evidence that children with higher serum magnesium concentrations are less likely to have asthma . The associations between serum vitamin D concentrations and asthma were age-dependent Aims : To investigate the effect of breast feeding on  allergic disease in infants up to 2 years of age . Methods : A birth cohort of 4089 infants was followed prospect ively in Stockholm , Sweden . Information about various exposures was obtained by parental question naires when the infants were 2 months old , and about allergic symptoms and feeding at 1 and 2 years of age . Duration of exclusive and partial breast feeding was assessed separately . Symptom related definitions of various allergic diseases were used . Odds ratios ( OR ) and 95 % confidence intervals ( CI ) were estimated in a multiple logistic regression model . Adjustments were made for potential confounders . Results : Children exclusively breast fed during four months or more exhibited less asthma ( 7.7 % v 12 % , ORadj = 0.7 , 95 % CI 0.5 to 0.8 ) , less atopic dermatitis ( 24 % v 27 % , ORadj = 0.8 , 95 % CI 0.7 to 1.0 ) , and less suspected allergic rhinitis ( 6.5 % v 9 % , ORadj = 0.7 , 95 % CI 0.5 to 1.0 ) by 2 years of age . There was a significant risk reduction for asthma related to partial breast feeding during six months or more ( ORadj = 0.7 , 95 % CI 0.5 to 0.9 ) . Three or more of five possible allergic disorders — asthma , suspected allergic rhinitis , atopic dermatitis , food allergy related symptoms , and suspected allergic respiratory symptoms after exposure to pets or pollen — were found in 6.5 % of the children . Exclusive breast feeding prevented children from having multiple allergic disease ( ORadj = 0.7 , 95 % CI 0.5 to 0.9 ) during the first two years of life . Conclusion : Exclusive breast feeding seems to have a preventive effect on the early development of allergic disease — that is , asthma , atopic dermatitis , and suspected allergic rhinitis , up to 2 years of age . This protective effect was also evident for multiple allergic disease BACKGROUND There is growing interest in the potential role of anti-inflammatory n-3 polyunsaturated fatty acids ( n-3 PUFAs ) in the prevention of allergic disease . OBJECTIVE We sought to determine whether maternal dietary supplementation with n-3 PUFAs during pregnancy could modify immune responses in infants . METHODS In a r and omized , controlled trial 98 atopic , pregnant women received fish oil ( 3.7 g n-3 PUFAs per day ) or placebo from 20 weeks ' gestation until delivery . Neonatal PUFA levels and immunologic response to allergens were measured at birth . RESULTS Eighty-three women completed the study .  Fish oil supplementation ( n = 40 ) achieved significantly higher proportions of n-3 PUFAs in neonatal erythrocyte membranes ( mean + /- SD , 17.75 % + /- 1.85 % as a percentage of total fatty acids ) compared with the control group ( n = 43 , 13.69 % + /- 1.22 % , P < .001 ) . All neonatal cytokine ( IL-5 , IL-13 , IL-10 , and IFN-gamma ) responses ( to all allergens ) tended to be lower in the fish oil group ( statistically significant only for IL-10 in response to cat ) . Although this study was not design ed to examine clinical effects , we noted that infants in the fish oil group were 3 times less likely to have a positive skin prick test to egg at 1 year of age ( odds ratio , 0.34 ; 95 % confidence interval , 0.11 to 1.02 ; P = .055 ) . Although there was no difference in the frequency of atopic dermatitis at 1 year of age , infants in the fish oil group also had significantly less severe disease ( odds ratio , 0.09 ; 95 % confidence interval , 0.01 to 0.94 ; P = .045 ) . CONCLUSIONS These data suggest a potential reduction in subsequent infant allergy after maternal PUFA supplementation . More detailed follow-up studies are required in larger cohorts to establish the robustness of these findings and to ascertain their significance in relation to longer-term modification of allergic disease in children BACKGROUND Avoidance of any one of the individual risk factors associated with childhood asthma has not been successful in preventing its development . OBJECTIVE The purpose of this study is to determine the effectiveness of a multifaceted intervention program for the primary prevention of asthma in high-risk infants at 7 years of age . METHODS Five hundred forty-five high-risk infants with an immediate family history of asthma and allergies were prospect ively r and omized into intervention or control groups prenatally . Intervention measures introduced before birth and during the first year of life included avoidance of house dust , pets , and environmental tobacco smoke and encouragement of breast-feeding with delayed introduction of solid foods . Assessment of outcomes at 7 years consisted of examination by pediatric allergists , methacholine inhalation tests , and allergy skin tests . RESULTS At 7 years , 469 of the 545 children were contacted , and 380 returned for further assessment . The prevalence of pediatric allergist-diagnosed asthma was significantly lower in the intervention group than in the control group ( 14.9 % vs 23.0 % ; adjusted risk ratio , 0.44 ; 95 % CI , 0.25 - 0.79 ) . The prevalence of allergic rhinitis , atopic dermatitis , atopy ( defined as positive skin test reactions to any common allergen ) , and bronchial hyperresponsiveness ( defined as the provocative concentration of methacholine that induced a 20 % decrease in FEV 1 from a postsaline value of less than 7.8 mg/mL ) were not significantly different between the 2 groups . The prevalence of asthma ( defined as wheeze without colds and the presence of bronchial hyperresponsiveness ) was also significantly lower in the intervention group compared with the control group ( 12.9 % vs 25.0 % ; adjusted risk ratio , 0.39 ; 95 % CI , 0.22 - 0.71 ) . CONCLUSION The multifaceted intervention program was effective in reducing the prevalence of asthma in high-risk children at 7 years of age We looked for an association between early exposure to pets and  asthma and wheezing in children whose mothers or fathers did or did not have a history of asthma . We followed up 448 children , who had at least one parent with a history of atopy , from birth to 5 years . Among children whose mothers had no history of asthma , exposure to a cat or a Fel d 1 concentration of at least 8 microg/g at the age of 2 - 3 months was associated with a reduced risk of wheezing between the ages of 1 and 5 years . However , among children whose mothers did have a history of asthma , such exposures were associated with an increased risk of wheezing at or after the age of 3 years . There was no association between wheezing and exposure to dog or dog allergen , and the father 's allergy status had no effect on the relation between childhood wheezing and cat exposure OBJECTIVE To investigate the effects of breastfeeding on  wheezing and current asthma in children 2 to 6 years of age . STUDY DESIGN Infants ( n=1105 ) were enrolled in a prospect i ve birth cohort in New Zeal and . Detailed information about infant feeding was collected using question naires administered at birth and at 3 , 6 , and 15 months . From this , duration s of exclusive and any breastfeeding were calculated . Information about wheezing and current asthma was collected at 2 , 3 , 4 , 5 , and 6 years . Logistic regression was used to model associations between breastfeeding and outcomes with and without adjustment for confounders . RESULTS After adjustment for confounders , each month of exclusive breastfeeding was associated with significant reductions in current asthma from 2 to 6 years ( all , P<.03 ) . Current asthma at 2 , 3 , and 4 years was also reduced by each month of any breastfeeding ( all , P<.005 ) . In atopic children , exclusive breastfeeding for ≥ 3 months reduced current asthma at ages 4 , 5 , and 6 by 62 % , 55 % , and 59 % , respectively . CONCLUSION Breastfeeding , particularly exclusive breastfeeding , protects against current asthma up to 6 years . Although exclusive breastfeeding reduced risk of current asthma  in all children to age 6 , the degree of protection beyond 3 years was more pronounced in atopic children BACKGROUND In a prospect i ve birth-cohort study , we assessed the relevance of mite and cat allergen exposure for the development of childhood asthma up to age 7 years . METHODS Of 1314 newborn infants enrolled in five German cities in 1990 , follow-up data at age 7 years were available for 939 children . Assessment s included repeated measurement of specific IgE to food and inhalant allergens , measurement of indoor allergen exposure at 6 months , 18 months , and 3 years of age , and yearly interviews by a paediatrician . At age 7 years , pulmonary function was tested and bronchial hyper-responsiveness was measured in 645 children . FINDINGS At age 7 , the prevalence of wheezing in the past 12 months was 10.0 % ( 94 of 938 ) , and 6.1 % ( 57 of 939 ) parents reported a doctor 's diagnosis of asthma in their children . Sensitisation to indoor allergens was associated with asthma , wheeze , and increased bronchial responsiveness . However , no relation between early indoor allergen exposure and the prevalence of asthma , wheeze , and bronchial hyper-responsiveness was seen . INTERPRETATION Our data do not support the hypothesis that exposure to environmental allergens causes asthma in childhood , but rather that the induction of specific IgE responses and the development of  childhood asthma  are determined by independent factors Early treatment of new-born high-risk children with certain probiotic strains has reduced the risk of atopic eczema . Whether probiotics reduce risk for airway inflammation in long term is not known . We aim ed at study ing the effect of probiotic treatment during the six first months of life on airway inflammation at age 5 yr . In a r and omized double-blind allergy prevention trial between 2000 and 2007 in Helsinki , Finl and , we gave a probiotic combination , plus pre-biotics , or placebo , to 1018 children during 6 months from birth . At age 5 , we measured exhaled nitric oxide ( FE(NO ) ) in a r and omized sub- population of 160 children . Allergic diseases and IgE-sensitization  were assessed in all infants .  FE(NO ) did not differ between probiotic and placebo groups , median ( interquartile range , IQR ) 5.45 ( 4.3 - 7.3 ) vs. 5.70 ( 3.9 - 6.8 ) ppb , p = 0.22 . FE(NO ) was elevated among those suffering from asthma during the first 5 yr than in healthy non-sensitized children ( p = 0.009 ) . FE(NO ) correlated positively with serum total and allergen-specific IgE concentrations . Early intervention with probiotics and pre-biotics does not affect airway inflammation later in childhood
OBJECTIVES Childhood asthma is a complex condition where many environmental factors are implicated in causation .
The aim of this study was to complete a systematic review of the literature describing associations between environmental exposures and the development of asthma in young children .