Risk factorsBy Mayo Clinic staff
Various factors increase the risk of miscarriage, including:
- Age. Women older than age 35 have a higher risk of miscarriage than do younger women. At age 35, you have about a 20 percent risk. At age 40, the risk is about 40 percent. And at age 45, it's about 80 percent. Paternal age also may play a role. Some studies indicate that the chance of miscarriage is higher if a woman's partner is age 35 or older, with the chance increasing as men age.
- Previous miscarriages. The risk of miscarriage is higher in women with a history of more than one previous miscarriage. After one miscarriage, your risk of miscarriage in a future pregnancy is about the same as women who have never had a miscarriage — 20 percent. After two miscarriages, your risk increases to about 28 percent.
- Chronic conditions. Women with certain chronic conditions, such as diabetes or thyroid disease, have a higher risk of miscarriage.
- Uterine or cervical problems. Certain uterine abnormalities or a weak or unusually short cervix may increase the risk of miscarriage.
- Smoking, alcohol and illicit drugs. Women who smoke or drink alcohol during pregnancy have a greater risk of miscarriage than do nonsmokers and women who avoid alcohol during pregnancy. Illicit drug use also increases the risk of miscarriage.
- Invasive prenatal tests. Some prenatal genetic tests, such as chorionic villus sampling and amniocentesis, carry a slight risk of miscarriage.
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