Miscarriage is the unplanned end of a pregnancy that occurs before you reach 20 weeks of pregnancy. According to the March of Dimes, as many as 50% of all pregnancies end in miscarriage — most often before a woman misses a menstrual period or even knows she is pregnant. About 15% of recognized pregnancies will end in a miscarriage.
More than 80% of miscarriages occur within the first three months of pregnancy. Miscarriages are less likely to occur after 20 weeks gestation; these are termed late miscarriages. Symptoms of a miscarriage include:
- Bleeding which progresses from light to heavy
- Severe cramps
- Abdominal pain
- Back pain
The causes of miscarriage are not well understood. Most miscarriages that occur in the first trimester are caused by chromosomal abnormalities in the baby. Chromosomes are tiny structures inside the cells of the body which carry many genes. Genes determine all of a person’s physical attributes, such as sex, hair and eye color, and blood type. Most chromosomal problems occur by chance and are not related to the mother’s or father’s health.
Miscarriages are also caused by a variety of other factors, including:
- Exposure to environmental and workplace hazards such as high levels of radiation or toxic agents
- Hormonal problems
- Uterine abnormalities
- Incompetent cervix (the cervix begins to widen and open too early, in the middle of pregnancy, without signs of pain or labor)
- Lifestyle factors such as smoking, drinking alcohol, or using illegal drugs
- Disorders of the immune system, including lupus
- Severe kidney disease
- Congenital heart disease
- Diabetes that is not controlled
- Thyroid disease
- Certain medications, such as the acne drug Accutane
- Severe malnutrition
In addition, women may be at increased risk for miscarriage as they get older due to the increased incidence of chromosomal abnormalities. There is no proof that stress or physical or sexual activity causes miscarriage.
A pelvic exam and/or an ultrasound may be done to confirm a miscarriage. If the miscarriage is complete and the uterus is empty, then no further treatment is usually required. Occasionally, the uterus is not completely emptied, so a dilation and curettage (D&C) procedure is performed. Or as an alternative to a D&C, certain medications can be given to cause your body to expel the contents in the uterus. This option may be more ideal in someone who wants to avoid surgery and whose condition is otherwise stable.
Blood tests, genetic tests, or medication may be necessary if a woman has more than two miscarriages in a row (called repeated miscarriage) to evaluate the cause of repeated miscarriage. If you’ve had two miscarriages in a row, you should stop trying to conceive and ask your health care provider to perform diagnostic tests to determine the cause of the miscarriages. Usually a miscarriage cannot be prevented and often occurs because the pregnancy is not normal. If a specific problem is identified with testing, then treatment options may be available.
At least 85% of women who have miscarriages have subsequent normal pregnancies and births. Having a miscarriage does not necessarily mean you have a fertility problem. On the other hand, about 1%-2% of women may have repeated miscarriages (three or more). There are treatments that may improve the chances for a successful pregnancy such as a procedure to close the cervix (called cerclage) to help maintain a viable pregnancy or if your blood type is Rh negative, your doctor may give you a blood product called Rh immune globulin (Rhogam). This prevents you from developing antibodies that could harm your baby as well as any of your future pregnancies. Your obstetrician may recommend treatment with progesterone, a hormone needed for implantation in the uterus.
Taking time to heal both physically and emotionally after a miscarriage is important. Above all, don’t blame yourself for the miscarriage. Counseling is available to help you and your partner cope with the loss. Remember, men grieve too, so it may be helpful to share your feelings of loss, frustration, helpless