miscarriage miscarriage miscarriage, also known in medical terms as a spontaneous abortion, is the death and expulsion of an embryo or fetus before it is able to survive independently. the term miscarriage is sometimes used to refer to all forms of pregnancy loss and pregnancy with abortive outcome before 20 weeks of gestation. miscarriageother namesspontaneous abortion, early pregnancy lossan ultrasound showing a gestational sac containing a yolk sac but no embryospecialtyobstetrics and gynaecology, neonatology, pediatricssymptomsvaginal bleeding with or without paincomplicationsinfection, bleeding, sadness, anxiety, guiltusual onsetbefore 20 weeks of pregnancycauseschromosomal abnormalities, uterine abnormalitiesrisk factorsbeing an older parent, previous miscarriage, exposure to tobacco smoke, obesity, diabetes, autoimmune diseases, drug or alcohol usediagnostic methodphysical examination, human chorionic gonadotropin, ultrasounddifferential diagnosisectopic pregnancy, implantation bleeding.preventionprenatal caretreatmentexpectant management, vacuum aspiration, emotional supportmedicationmisoprostolfrequency10–50% of pregnancies miscarriage before 6 weeks of gestation is defined by eshre as biochemical loss. once ultrasound or histological evidence shows that a pregnancy has existed, the used term is clinical miscarriage, which can be early before 12 weeks and late between 12-21 weeks. fetal death after 20 weeks of gestation is also known as a stillbirth. the most common symptom of a miscarriage is vaginal bleeding with or without pain. sadness, anxiety, and guilt may occur afterwards. tissue and clot-like material may leave the uterus and pass through and out of the vagina. recurrent miscarriage (also referred to medically as recurrent spontaneous abortion or rsa) may also be considered a form of infertility. risk factors for miscarriage include being an older parent, previous miscarriage, exposure to tobacco smoke, obesity, diabetes, thyroid problems, and drug or alcohol use. about 80% of miscarriages occur in the first 12 weeks of pregnancy (the first trimester). the underlying cause in about half of cases involves chromosomal abnormalities. diagnosis of a miscarriage may involve checking to see if the cervix is open or sealed, testing blood levels of human chorionic gonadotropin (hcg), and an ultrasound. other conditions that can produce similar symptoms include an ectopic pregnancy and implantation bleeding. prevention is occasionally possible with good prenatal care. avoiding drugs, alcohol, infectious diseases, and radiation may decrease the risk of miscarriage. no specific treatment is usually needed during the first 7 to 14 days. most miscarriages will complete without additional interventions. occasionally the medication misoprostol or a procedure such as vacuum aspiration is used to remove the remaining tissue. women who have a blood type of rhesus negative (rh negative) may require rho(d) immune globulin. pain medication may be beneficial. emotional support may help with processing the loss. miscarriage is the most common complication of early pregnancy. among women who know they are pregnant, the miscarriage rate is roughly 10% to 20%, while rates among all fertilisation is around 30% to 50%. in those under the age of 35 the risk is about 10% while it is about 45% in those over the age of 40. risk begins to increase around the age of 30. about 5% of women have two miscarriages in a row. some recommend not using the term "abortion" in discussions with those experiencing a miscarriage in an effort to decrease distress. in britain, the term "miscarriage" has replaced any use of the term "spontaneous abortion" in relation to pregnancy loss and in response to complaints of insensitivity towards women who had suffered such loss. an additional benefit of this change is reducing confusion among medical laymen, who may not realize that the term "spontaneous abortion" refers to a naturally-occurring medical phenomenon, and not the intentional termination of pregnancy. signs and symptoms signs of a miscarriage include vaginal spotting, abdominal pain, cramping, and fluid, blood clots, and tissue passing from the vagina. bleeding can be a symptom of miscarriage, but many women also have bleeding in early pregnancy and do not miscarry. bleeding during the first half of pregnancy may be referred to as a threatened miscarriage. of those who seek treatment for bleeding during pregnancy, about half will miscarry. miscarriage may be detected during an ultrasound exam, or through serial human chorionic gonadotropin (hcg) testing. risk factors further information: list of miscarriage risks miscarriage may occur for many reasons, not all of which can be identified. risk factors are those things that increase the likelihood of having a miscarriage but do not necessarily cause a miscarriage. up to 70 conditions, infections, medical procedures, lifestyle factors, occupational exposures, chemical exposure, and shift work are associated with increased risk for miscarriage. some of these risks include endocrine, genetic, uterine, or hormonal abnormalities, reproductive tract infections, and tissue rejection caused by an autoimmune disorder. first trimester chromosomal abnormalities found in first trimester miscarriages description proportion of total normal 45–55% autosomal trisomy 22–32% monosomy x (45, x) 5–20% triploidy 6–8% structural abnormality ofthe chromosome 2% double or triple trisomy 0.7–2.0% translocation unknown most clinically apparent miscarriages (two-thirds to three-quarters in various studies) occur during the first trimester. about 30% to 40% of all fertilized eggs miscarry, often before the pregnancy is known. the embryo typically dies before the pregnancy is expelled; bleeding into the decidua basalis and tissue necrosis causes uterine contractions to expel the pregnancy. early miscarriages can be due to a developmental abnormality of the placenta or other embryonic tissues. in some instances an embryo does not form but other tissues do. this has been called a "blighted ovum". successful implantation of the zygote into the uterus is most likely eight to ten days after fertilization. if the zygote has not implanted by day ten, implantation becomes increasingly unlikely in subsequent days. a chemical pregnancy is a pregnancy that was detected by testing but ends in miscarriage before or around the time of the next expected period. chromosomal abnormalities are found in more than half of embryos miscarried in the first 13 weeks. half of embryonic miscarriages (25% of all miscarriages) have an aneuploidy (abnormal number of chromosomes). common chromosome abnormalities found in miscarriages include an autosomal trisomy (22–32%), monosomy x (5–20%), triploidy (6–8%), tetraploidy (2–4%), or other structural chromosomal abnormalities (2%). genetic problems are more likely to occur with older parents; this may account for the higher rates observed in older women. luteal phase progesterone deficiency may or may not be a contributing factor to miscarriage. second and third trimesters second trimester losses may be due to maternal factors such as uterine malformation, growths in the uterus (fibroids), or cervical problems. these conditions also may contribute to premature birth. unlike first-trimester miscarriages, second-trimester miscarriages are less likely to be caused by a genetic abnormality; chromosomal aberrations are found in a third of cases. infection during the third trimester can cause a miscarriage. age further information: advanced maternal age the age of the pregnant woman is a significant risk factor. miscarriage rates increase steadily with age, with more substantial increases after age 35. in those under the age of 35 the risk is about 10% while it is about 45% in those over the age of 40. risk begins to increase around the age of 30. paternal age is associated with increased risk. obesity, eating disorders and caffeine not only is obesity associated with miscarriage; it can result in sub-fertility and other adverse pregnancy outcomes. recurrent miscarriage is also related to obesity. women with bulimia nervosa and anorexia nervosa may have a greater risk for miscarriage. nutrient deficiencies have not been found to impact miscarriage rates but hyperemesis gravidarum sometimes precedes a miscarriage. caffeine consumption also has been correlated to miscarriage rates, at least at higher levels of intake. however, such higher rates are statistically significant only in certain circumstances. vitamin supplementation has generally not shown to be effective in preventing miscarriage. chinese traditional medicine has not been found to prevent miscarriage. endocrine disorders disorders of the thyroid may affect pregnancy outcomes. related to this, iodine deficiency is strongly associated with an increased risk of miscarriage. the risk of miscarriage is increased in those with poorly controlled insulin-dependent diabetes mellitus. women with well-controlled diabetes have the same risk of miscarriage as those without diabetes. food poisoning ingesting food that has been contaminated with listeriosis, toxoplasmosis, and salmonella is associated with an increased risk of miscarriage. amniocentesis and chorionic villus sampling amniocentesis and chorionic villus sampling (cvs) are procedures conducted to assess the fetus. a sample of amniotic fluid is obtained by the insertion of a needle through the abdomen and into the uterus. chorionic villus sampling is a similar procedure with a sample of tissue removed rather than fluid. these procedures are not associated with pregnancy loss during the second trimester but they are associated with miscarriages and birth defects in the first trimester. miscarriage caused by invasive prenatal diagnosis (chorionic villus sampling (cvs) and amniocentesis) is rare (about 1%). surgery the effects of surgery on pregnancy are not well-known including the effects of bariatric surgery. abdominal and pelvic surgery are not risk factors for miscarriage. ovarian tumours and cysts that are removed have not been found to increase the risk of miscarriage. the exception to this is the removal of the corpus luteum from the ovary. this can cause fluctuations in the hormones necessary to maintain the pregnancy. medications there is no significant association between antidepressant medication exposure and miscarriage. the risk of miscarriage is not likely decreased by discontinuing ssris prior to pregnancy. some available data suggest that there is a small increased risk of miscarriage for women taking any antidepressant, though this risk becomes less statistically significant when excluding studies of poor quality. medicines that increase the risk of miscarriage include: retinoids nonsteroidal anti-inflammatory drugs (nsaids), such as ibuprofen misoprostol methotrexate statins immunizations immunizations have not been found to cause miscarriage. live vaccinations, like the mmr vaccine, can theoretically cause damage to the fetus as the live virus can cross the placenta and potentially increase the risk for miscarriage. therefore, the center for disease control (cdc) recommends against pregnant women receiving live vaccinations. however, there is no clear evidence that has shown live vaccinations to increase the risk for miscarriage or fetal abnormalities. some live vaccinations include: mmr, varicella, certain types of the influenza vaccine, and rotavirus. treatments for cancer ionizing radiation levels given to a woman during cancer treatment cause miscarriage. exposure can also impact fertility. the use of chemotherapeutic drugs used to treat childhood cancer increases the risk of future miscarriage. pre-existing diseases several pre-existing diseases in pregnancy can potentially increase the risk of miscarriage, including diabetes, polycystic ovary syndrome (pcos), hypothyroidism, certain infectious diseases, and autoimmune diseases. pcos may increase the risk of miscarriage. two studies suggested treatment with the drug metformin significantly lowers the rate of miscarriage in women with pcos, but the quality of these studies has been questioned. metformin treatment in pregnancy has not been shown to be safe. in 2007 the royal college of obstetricians and gynaecologists also recommended against use of the drug to prevent miscarriage. thrombophilias or defects in coagulation and bleeding were once thought to be a risk in miscarriage but have been subsequently questioned. severe cases of hypothyroidism increase the risk of miscarriage. the effect of milder cases of hypothyroidism on miscarriage rates has not been established. a condition called luteal phase defect (lpd) is a failure of the uterine lining to be fully prepared for pregnancy. this can keep a fertilized egg from implanting or result in miscarriage. mycoplasma genitalium infection is associated with increased risk of preterm birth and miscarriage. infections can increase the risk of a miscarriage: rubella (german measles), cytomegalovirus, bacterial vaginosis, hiv, chlamydia, gonorrhoea, syphilis, and malaria. immune status autoimmunity is a possible cause of recurrent or late-term miscarriages. in the case of an autoimmune-induced miscarriage, the woman's body attacks the growing fetus or prevents normal pregnancy progression. autoimmune disease may cause abnormalities in embryos, which in turn may lead to miscarriage. as an example, celiac disease increases the risk of miscarriage by an odds ratio of approximately 1.4. a disruption in normal immune function can lead to the formation of antiphospholipid antibody syndrome. this will affect the ability to continue the pregnancy, and if a woman has repeated miscarriages, she can be tested for it. approximately 15% of recurrent miscarriages are related to immunologic factors. the presence of anti-thyroid autoantibodies is associated with an increased risk with an odds ratio of 3.73 and 95% confidence interval 1.8–7.6. having lupus also increases the risk for miscarriage.