A miscarriage is the spontaneous loss of an embryo or fetus. If it occurs after 20 weeks, it is called a stillbirth. Medically known as a "spontaneous abortion," a miscarriage is relatively common, occurring in one in six pregnancies. It is especially common during the first few weeks of pregnancy. The early spontaneous abortion rate is estimated to be 45 percent of all pregnancies. Many women may not know they were pregnant and experienced an early spontaneous abortion. Because it is so prevalent, for most women a history of one or two miscarriages does not mean there is anything wrong with the woman's reproductive health, and the prognosis for future childbearing is excellent. Miscarriages are more likely to occur with age and the number of previous miscarriages. Warning signs include vaginal bleeding, passing blood clots, cramps, pain in the lower back and the absence or disappearance of morning sickness, breast enlargement and other signs of pregnancy. The most common cause of miscarriage is a chromosomal abnormality of the fetus, which accounts for approximately 50 percent of all known spontaneous abortions and 85 percent of miscarriages. The early loss of embryos mostly represents a natural disposal of abnormal early embryos that could not have developed normally. It is estimated that without this natural process the percentage of newborn infants with congenital anomalies would rise from about 3 percent to 12 percent. Conditions in the mother such as diabetes, hormonal imbalances or anatomic problems of the uterus or cervix can also trigger miscarriage. So can certain viral and bacterial infections, recreational drug and alcohol use, and exposure to environmental toxins such as arsenic, lead and formaldehyde. Despite debate, a 1991 study found that using a video display terminal doesn't increase the risk of miscarriage. If you are bleeding or have any other symptom that leads you to suspect that you may be miscarrying, call your clinician immediately. Don't have sexual intercourse or take part in strenuous activities. If the bleeding stops and pain ends, you are likely to continue with a normal pregnancy. While medical treatment can't stop an impending pregnancy loss, you may need a dilation and curettage to cleanse the uterus of retained tissues if the miscarriage isn't complete. Your doctor will advise you how long to wait before you try for another pregnancy, usually one or two menstrual cycles. Women with recurrent (more than two) miscarriages should be evaluated by an OB/GYN. Last Updated: 9/23/2002
The Johns Hopkins University 1996-2003. All rights reserved. This information is not intended to provide advice on personal medical matters, nor is it intended to be a substitute for consultation. | 
