A randomized trial of intrapartum electronic fetal heart rate monitoring versus intermittent auscultation. Intermittent versus continuous electronic monitoring in labour: a randomised study. Controlled trial of fetal intensive care. An assessment of continuous fetal heart rate monitoring in labor. A randomized trial. A randomized trial of electronic fetal monitoring in preterm labor. The Dublin randomized controlled trial of intrapartum fetal heart rate monitoring. Intrapartum electronic fetal monitoring vs. intermittent auscultation in postcesarean pregnancies. A prospective comparison of selective and universal electronic fetal monitoring in 34,995 pregnancies. The evaluation of continuous fetal heart rate monitoring in high-risk pregnancy. A controlled trial of the differential effects of intrapartum fetal monitoring. Intrapartum fetal heart rate monitoring in a combined low- and high-risk population: a controlled clinical trial. A controlled trial of fetal heart rate monitoring in a low-risk obstetric population.
To determine whether continuous intrapartum electronic fetal heart rate monitoring (EFM) is associated with decreased perinatal mortality and morbidity compared with intermittent auscultation.
                The study was conducted simultaneously at two university hospitals in Athens, Greece (Alexandra and Marika Iliadi Hospitals) from October 1, 1990 to June 30, 1991. All patients with singleton living fetuses and gestational ages of 26 weeks or greater were eligible for inclusion. The participants were assigned to continuous EFM or intermittent auscultation based on the flip of a coin. Both groups were followed during labor according to the most recent ACOG guidelines. However, fetal scalp blood pH and crossover from one group to the other were not used.
                A total of 1428 patients were included, 746 in the EFM group and 682 in the auscultation group. There were no differences between the groups in terms of maternal age, gravidity, parity, gestational age, and number of antepartum high-risk factors. More patients monitored electronically received oxytocin for either augmentation (52.4 versus 38.1%; P = .0001) or induction (15.6 versus 7%; P = .0001). The length of labor was longer in the EFM group (first stage 6.1 +/- 4.3 versus 5.5 +/- 3.7 hours; P = .006; second stage 29.4 +/- 18.6 versus 26.9 +/- 16.9 minutes; P = .01). There was a higher incidence of nonreassuring fetal heart rate patterns in the EFM group (23.4 versus 10.7%; P = .0001) and a higher rate of surgical intervention (11.2 versus 4.8%; P = .0001). This difference pertained to both vacuum extraction (5.8 versus 2.4%; P = .002) and cesarean delivery for suspected fetal distress (5.3 versus 2.3%; P = .005). There were no differences in 1- and 5-minute Apgar scores, fetal acidosis at birth, need for neonatal resuscitation, neonatal intensive care unit admission, use of assisted ventilation, neonatal hospital stay, or any other neonatal complications. Two neonatal deaths occurred in the EFM group and nine perinatal deaths in the auscultation group (two intrapartum and seven neonatal deaths). The perinatal mortality rates were 2.6 per 1000 and 13 per 1000 total births, respectively (P = .04). The two deaths in the EFM group and three of the neonatal deaths in the auscultation group may not have been prevented by intrapartum monitoring; however, four neonatal deaths from the auscultation group occurred in depressed (5-minute Apgar scores less than 7), acidotic (cord artery pH at or below 7.13) infants. The perinatal death rate related to fetal hypoxia was significantly less in the EFM group (zero of 746 versus six of 682; P = .03).
                In this controlled trial, intrapartum EFM, as the primary and only method of intrapartum fetal surveillance, was associated with decreased perinatal mortality due to fetal hypoxia but also with higher rates of surgical intervention for suspected fetal distress. To compare the efficacy in detecting signs of fetal hypoxia in labour of intermittent (I-group) versus continuous (C-group) electronic fetal monitoring in women with low or moderate risk factors for fetal distress.
                A prospective, randomised study.
                A tertiary referral centre.
                Four thousand and forty-four parturients at low risk for obstetric complications with a reactive fetal heart rate admission test at arrival in labour. During the study period (October 5 1989 to May 31 1991), 5647 women were delivered in the labour ward. Of these, 1178 women (20.9%) were excluded because of high risk factors in pregnancy or at admission for labour, including women undergoing elective caesarean section. Of the remaining 4469 women 4044 (90.5%) were randomised to either intermittent (n = 2015) or continuous monitoring (n = 2029) during the first stage of labour.
                In the C-group the fetal heart rate was recorded continuously with electronic fetal monitoring during the first stage of labour. In the I-group the fetal heart rate was recorded with electronic fetal monitoring for 10 to 30 min every 2 to 2.5 h during the first stage of labour, and the fetal heart rate was auscultated every 15 to 30 min in between recording periods. If complications occurred, recording was changed to continuous. In the second stage of labour all the women were monitored continuously. Umbilical cord artery acid-base status was assessed at birth.
                Duration of electronic fetal monitoring, rates of abnormal fetal heart rate patterns, caesarean section for fetal distress, acidosis in umbilical cord arterial blood at birth, Apgar scores of less than 7 at 1 or 5 min, and referrals to the neonatal intensive care unit.
                There were no significant differences between the study groups in the incidence of ominous fetal heart rate recordings: 6.3% (I-group) versus 6.6% (C-group), or the interval from arrival to first detected abnormal fetal heart rate, although the number of suspicious fetal heart rate patterns was higher in the C-group (28.6%) than in the I-group (24.6%). In the I-group electronic fetal monitoring was performed for (median monitoring time) 38.8% of the first stage of labour as compared with 78.6% in the C-group. The incidence of caesarean section for fetal distress was similarly low in both groups: 1.2% versus 1.0%. There were no significant differences in the immediate neonatal outcome in terms of umbilical artery pH, Apgar scores, or admissions to the neonatal care unit.
                Intermittent use of electronic fetal monitoring at regular intervals (with stethoscopic auscultation in between) appears to be as safe as continuous electronic fetal monitoring in low risk labours. A fetal intensive care unit was formed at the Queen Victoria Memorial Hospital in 1972. Because of some doubt concerning the value of fetal intensive care, a controlled clinical trial including all high-risk patients was performed. The trial clearly showed that intensive care is associated with improved neurologic and biochemical status of the neonate; however, it is possible that this improvement results from the use of fetal diagnostic tests or some other factor associated with intensive care. Sufficient evidence was gathered to warrant the continuation of fetal intensive care in this hospital, but in other contries, where funding is difficult to obtain, a controlled trial would appear justified. Intrapartum continuous fetal heart rate monitoring has been routinely performed at the Jessop Hospital for Women for some years. However, no controlled trials had ever been performed to show its advantages over intermittent auscultation in low-risk patients. A prospective randomized study of 504 patients compared continuous fetal heart rate monitoring with intermittent auscultation. There was no significant difference between the two groups in neonatal deaths, Apgar scores, maternal and neonatal morbidity, and cord blood gases. The cesarean section rate was significantly increased (p less than 0.05) in the monitored patients but this did not seem attributable to fetal monitoring. No beneficial or deleterious effects of continuous fetal heart rate monitoring in labor were shown. Intrapartum electronic fetal heart rate (FHR) monitoring and fetal blood gas sampling were compared with periodic auscultation of FHR in a multicentered randomized trial of preterm singleton pregnancies with fetal weights of 700-1750 g. Two hundred forty-six pregnancies were studied (electronic FHR monitoring N = 122, auscultation N = 124). Perinatal or infant death was associated with 14% of pregnancies with electronic FHR monitoring and 15% with auscultation. No significant differences were noted in the prevalence of low five-minute Apgar scores, intrapartum acidosis, intracranial hemorrhage, or frequency of cesarean section (P greater than .10). Compared with electronic FHR monitoring, intrapartum auscultation as done in this study is unlikely to be associated with detectable differences in perinatal outcomes within the high-risk setting of preterm labor. In a randomized controlled trial involving 12,964 women, a policy of continuous electronic intrapartum fetal heart monitoring was compared with an alternative policy of intermittent auscultation, both policies including an option to measure fetal scalp blood pH. Women allocated to electronic fetal heart monitoring had shorter labors and received less analgesia. The caesarean delivery rates were 2.4% for electronic fetal heart monitoring and 2.2% for intermittent auscultation but this small difference arose from the identification of nearly twice as many fetuses with low scalp pH (less than 7.20) in the electronic fetal heart monitoring group. The forceps delivery rate was 8.2% in the electronic fetal heart monitoring group compared with 6.3% in the intermittent auscultation group, and this excess was explained by more instrumental deliveries prompted by fetal heart rate abnormalities. There were 14 stillbirths and neonatal deaths in each group, with a similar distribution of causes. There were no apparent differences in the rates of low Apgar scores, need for resuscitation, or transfer to the special care nursery. Cases of neonatal seizures and persistent abnormal neurological signs followed by survival were twice as frequent in the intermittent auscultation group, and this differential effect was related to duration of labor. Follow-up at 1 year of babies who survived neonatal seizures revealed three clearly abnormal infants in each group. The implications of these findings for both theory and practice are discussed. nan We investigated the effects of using intrapartum electronic fetal monitoring in all pregnancies, as compared with using it only in cases in which the fetus is judged to be at high risk. Predominant risk factors included oxytocin stimulation of labor, dysfunctional labor, abnormal fetal heart rate, or meconium-stained amniotic fluid. This prospective alternate-month clinical trial took place over a 36-month period during which 34,995 women gave birth. In alternate months, either 7 (for "selective monitoring") or 19 (for "universal monitoring") fetal monitors were made available in the labor and delivery unit. During the "selective" months, 6420 of 17,409 women (37 percent) were electronically monitored, as compared with 13,956 of 17,586 women (79 percent) during the "universal months." Universal monitoring was associated with a small but significant increase in the incidence of delivery by cesarean section because of fetal distress, but perinatal outcomes as assessed by intrapartum stillbirths, low Apgar scores, a need for assisted ventilation of the newborn, admission to the intensive care nursery, or neonatal seizures were not significantly different. We conclude that not all pregnancies, and particularly not those considered at low risk of perinatal complications, need continuous electronic fetal monitoring during labor. Intrapartum electronic fetal heart rate monitoring of the high-risk obstetric patient is thought to improve the perinatal outcome. A prospective randomized study of 483 high-risk obstetric patients in labor was carried out comparing the effectiveness of electronic fetal monitoring with auscultation of fetal heart tones. The infant outcome was measured by neonatal death, Apgar scores, cord blood gases, and neonatal nursery morbidity. There were no differences in the infant outcomes in any measured category between the electronically monitored group and the auscultated group. The cesarean section rate was markedly increased in the monitored group (16.5 vs. 6.8 per cent in the auscultated patients). The presumptive benefits of electronic fetal monitoring for improving fetal outcome were not found in this study. A controlled prospective study of the differential effects of intrapartum fetal monitoring on mothers and infants has been conducted at Denver General Hospital, Denver, Colorado. A total of 690 high-risk obstetric patients in labor were randomly assigned to one of three monitoring groups--auscultation, electronic fetal monitoring alone, or electronic monitoring with the option to scalp sample. There were no differences in immediate infant outcomes in any measured category (Apgar scores, cord blood gases, neonatal death, neonatal morbidity, nursery course) among the three groups. There were no differences in rates of infant or maternal infections. The cesarean section rate was markedly increased in the electronically monitored groups, especially in the electronically monitored alone (18%) as compared with the auscultated (6%) (P less than 0.005). In this controlled trial electronic monitoring did not improve neonatal outcomes and the mothers were at increased risk of cesarean section. In a prospective clinical randomized investigation 487 women had the condition of the fetus during labour supervised by means of stethoscope (AUS), while 482 women went through labour under surveillance of electronic fetal monitoring, cardiotocography (EFM). 349 women refused to participate in the investigation (NAI) and had delivery conducted according to the normal procedures of the department (70% AUS, 30% EFM). Significantly more pathological fetal heart rate patterns (FHR) were found in the EFM group compared to the AUS group in both the first and the second stage of labour. As a result significantly more vacuum extractions were performed in the EFM group than in the AUS group, while no statistical difference was found between the groups in the incidence of acute cesarean sections carried out for asphyxia. One case of intrapartum death occurred in the AUS group. No differences were found in Apgar scores after 1 and 5 min or in neonatal morbidity at examination on the 2nd and 5th days after delivery. A tendency towards more biochemically compromised children was found in the AUS group. The specificity for both methods was found to be acceptably high (80%), while the predictive value for both methods was low (50%). More research is therefore urgently needed to evaluate supplementary investigations and parameters for the evaluation of the intrapartum fetal condition. A controlled trial of fetal heart rate (FHR) monitoring in a low-risk obstetric population was carried out in 989 patients at the Mercy Maternity Hospital and Queen Victoria Medical Centre. The use of monitoring failed to demonstrate any improvement in perinatal outcome. Monitoring was associated with an increased intervention rate and a small increase in the number of babies who remained in the isolette beyond 3 days. This study does not support the view that FHR monitoring should be used in all labors. Further study in a larger sample is recommended.
Continuous cardiotocography during labour is associated with a reduction in neonatal seizures, but no significant differences in cerebral palsy, infant mortality or other standard measures of neonatal well-being. However, continuous cardiotocography was associated with an increase in caesarean sections and instrumental vaginal births. The challenge is how best to convey these results to women to enable them to make an informed choice without compromising the normality of labour.