Miscarriages are a common occurrence, with 15-20% of pregnancies resulting in miscarriage. Miscarriage usually occurs in the first trimester, although it may occur later in pregnancy. Recurrent miscarriage is classified by having 3 or more miscarriages in a row, regardless of other healthy pregnancies. Recurrent miscarriage can have underlying causes and there are tests that may help point to the reason. Despite the tests available, only about half of cases come up with definitive answers that can explain the recurrent miscarriages. Known causes for recurrent early and late miscarriage include: genetic or chromosomal problems, structural problems with the uterus, endocrine system problems, or premature labor. The risk for miscarriage also increases with the age of the parents. Some pregnant women experience symptoms before a miscarriage, while others are asymptomatic. Some of the possible symptoms of miscarriage include: vaginal spotting, vaginal or uterine cramping, and absence of fetal movement. If any of these symptoms occur, call your doctor immediately.