Miscarriage is when a baby dies in the womb before 20 weeks of pregnancy.
Usually, miscarriage is a one-time thing. Most women who miscarry don’t have the same problem in another pregnancy. But about 1 percent of couples have repeat miscarriages. This means the woman has two, three or more miscarriages in a row.
There may be some specific problem that causes repeat miscarriages. But these causes are known in only half of all cases. Even without treatment, about 60 to 70 percent of women with repeat miscarriages go on to have a successful pregnancy.
Known causes of repeat miscarriages include:
Problems with the uterus or cervix. The uterus (womb) is where your baby grows inside you. The cervix is the opening to the uterus that sits at the top of the vagina. Problems with the uterus and cervix cause 10 to 15 percent of repeat miscarriages. Examples include:
- A uterus that isn’t shaped correctly or is divided in two. Sometimes these can be corrected with surgery.
- Fibroids (growths) in the uterus or scars from surgery on the uterus. Fibroids and scars can limit space for the baby or interfere with the baby’s blood supply.
- Cervical insufficiency (also called incompetent cervix). This is when the cervix is weak and opens too early. This can lead to miscarriage, usually in the second trimester. To help prevent miscarriage, your provider may recommend cerclage. This is a stitch your provider puts in your cervix to help keep it closed.
Chromosome problems. Chromosomes are tiny, thread-like structures in cells that carry our genes. Each person has 23 pairs of chromosomes (46 in all). One chromosome in each pair comes from the mother, and the other comes from the father. Most chromosome problems happen when an egg or sperm has too many or too few chromosomes. Chromosome problems usually happen just once. But in about 2 to 4 percent of couples with repeat miscarriages, one parent has a chromosome problem that doesn't affect his own health but can cause problems in the baby. Both parents should have a test called a karyotype to check for chromosome problems.
Antiphospholipid syndrome. This is a condition of the immune system that increases the risk of blood clots in the placenta. Your immune system is what protects your body from infection. Antiphospholipid syndrome causes 5 to 10 percent of repeat miscarriages. Your provider can test you for this condition with a blood test. Treatment is with low doses of aspirin and a medicine that helps thin the blood.
Hormone problems. Hormones are chemicals made by the body. If you have too much or too little of certain hormones, your chances of miscarriage may increase.
- Luteal phase defect. This is when you have low levels of progesterone over several menstrual cycles. Progesterone is a hormone that helps regulate your monthly periods and gets your body ready for pregnancy. Your provider may recommend treatment with various forms of progesterone.
- Polycystic ovary syndrome (also called PCOS). This condition happens when you have hormone problems along with cysts on the ovaries. A cyst is a closed pocket of that contains air, fluid or semi-solid substances. Your provider may recommend treatment with progesterone or other medicine.
Blood-clotting conditions called thrombophilias. This group of conditions is inherited, which means it’s passed down from parents to children. It increases the risk of blood clots. Your provider may recommend treatment with aspirin and other medicine.
Infections. Some infections of your reproductive organs, like the ovaries, uterus and cervix, may play a role in repeat miscarriages.
Harmful chemicals. If you or your partner work with certain harmful chemicals, you may be more likely to have repeat miscarriage. These chemicals include solvents, like paint thinner. If you’re worried about being around harmful chemicals, tell your health care provider.
Last reviewed September 2012
See also: Miscarriage, Treatment after miscarriage
Frequently Asked Questions
How do you know if you’re having a miscarriage?
Signs of a miscarriage can include vaginal spotting or bleeding, abdominal pain or cramping, and fluid or tissue passing from the vagina. Although vaginal bleeding is a common symptom of miscarriage, many women have spotting early in their pregnancy but don’t miscarry. But if you’re pregnant and have bleeding or spotting, contact your health care provider right away.
What is dilation and curettage?
Dilation and curettage (also called D&C) is when a doctor removes tissue from the lining of a woman's uterus. Dilation ("D") is a widening of the cervix to allow medical instruments into the uterus. Curettage ("C") is the scraping of the walls of the uterus.
Some women have a D&C after a miscarriage to remove tissue. Providers also use D&C to treat heavy bleeding or to help diagnose infection, cancer and other diseases.
After a D&C, you can return to your regular activities as soon as you feel better, maybe even the same day. You may have vaginal bleeding, pelvic cramps and back pain for a few days after the procedure. Talk to your provider about medicine you can take for pain. Don’t use tampons or have sex for 1 to 2 weeks after the procedure.
When can I try to get pregnant again?
For most women, it's best to wait at least 18 months before getting pregnant again. This amount of time is best if you miscarry, or if your baby is stillborn, or if your baby dies after birth. Waiting this long gives your body enough time to heal between pregnancies. Also, giving yourself this time may help you feel less worried about your next pregnancy. Depending on your age or other medical reasons, you may not be able to wait this long. Talk to your provider about what's right for you.