Miscarriage (also called early pregnancy loss) is when a baby dies in the womb (uterus) before 20 weeks of pregnancy. For women who know they’re pregnant, about 10 to 15 in 100 pregnancies (10 to 15 percent) end in miscarriage. Most miscarriages happen in the first trimester before the 12th week of pregnancy. Miscarriage in the second trimester (between 13 and 19 weeks) happens in 1 to 5 in 100 (1 to 5 percent) pregnancies.

As many as half of all pregnancies may end in miscarriage. We don’t know the exact number because a miscarriage may happen before a woman knows she’s pregnant. Most women who miscarry go on to have a healthy pregnancy later.