If you've had a miscarriage, you've probably wondered why it happened. Some women even blame themselves for miscarriage. But miscarriage is rarely caused by something the pregnant woman did. Having sex, exercise, a mild fall, and most medications do not cause miscarriage.
It may be difficult for health care providers to know what caused a particular miscarriage. But we do know some things that make miscarriage more likely in general:
- The embryo or fetus has a chromosome that causes it to develop abnormally. This is not usually a sign of a condition that could cause problems in future pregnancies. It usually happens by chance when the fertilized egg divides and grows. This problem causes at least half of miscarriages.
- A woman's risk of miscarriage increases as she ages.
- Severe chronic illness — such as poorly controlled diabetes, rheumatoid arthritis, or lupus — can cause miscarriage.
- Severe trauma and very serious infections also can cause miscarriage.
- Abnormalities in the uterus, like scar tissue or uterine fibroids, can cause late miscarriages — after three months.
- Smoking, the use of alcohol or cocaine, and heavy caffeine use have all been tied to miscarriage.
- Women who are underweight or overweight have a greater risk of miscarriage than other women.
- Women who have had two or more miscarriages in a row are at a greater risk of having future miscarriages.
