Though any woman can miscarry, some are more likely to miscarry than others. Here are some risk factors:
- Age: Older women are more likely to conceive babies with chromosomal abnormalities and to miscarry them as a result. In fact, 40-year-olds are about twice as likely to miscarry as 20-year-olds. Your risk of miscarriage also rises with each child you bear.
- A history of miscarriages: Women who have had two or more miscarriages in a row are more likely than other women to miscarry again.
- Chronic diseases or disorders: Poorly controlled diabetes and certain inherited blood clotting disorders, autoimmune disorders (such as antiphospholipid syndrome or 10011584 lupus), and hormonal disorders (such as polycystic ovary syndrome) are some of the conditions that could increase the risk of miscarriage.
- Uterine or cervical problems: Having certain congenital uterine abnormalities, severe uterine adhesions (bands of scar tissue), or a weak or abnormally short cervix (known as cervical insufficiency) up the odds for a miscarriage. The link between one type of uterine fibroid (a common, benign growth) and miscarriage is controversial, but most fibroids don't cause problems.
- A history of birth defects or genetic problems: If you, your partner, or family members have a genetic abnormality, have had one identified in a previous pregnancy, or have given birth to a child with a birth defect, you're at higher risk for miscarriage.
- Infections: Research has shown a somewhat higher risk for miscarriage if you have listeria, mumps, rubella, measles, cytomegalovirus, parvovirus, gonorrhea, HIV, and certain other infections.
- Smoking, drinking, and using drugs: Smoking, drinking alcohol, and using drugs like cocaine and MDMA (ecstasy) during pregnancy can all increase your risk for miscarriage. Some studies show an association between caffeine consumption and a higher risk of miscarriage.
- Medications: Some medications have been linked to increased risk of miscarriage, so it's important to ask your caregiver about the safety of any medications you're taking, even while you're trying to conceive. This goes for prescription and over-the-counter drugs, including nonsteroidal anti-inflammatory drugs (NSAIDs) like ibuprofen and aspirin.
- Environmental toxins: Environmental factors that might increase your risk include lead; arsenic; some chemicals, like formaldehyde, benzene, and ethylene oxide; and large doses of radiation or anesthetic gases.
- Paternal factors: Little is known about how the father's condition contributes to a couple's risk for miscarriage, though the risk does rise with the father's age. Researchers are studying the extent to which sperm could be damaged by environmental toxins but still manage to fertilize an egg. Some studies have found a greater risk of miscarriage when the father has been exposed to mercury, lead, and some industrial chemicals and pesticides.
- Obesity: Some studies show a link between obesity and miscarriage.
- Diagnostic procedures: There's a small increased risk of miscarriage after chorionic villus sampling and amniocentesis, which may performed for diagnostic genetic testing.