The hallmarks of a miscarriage include heavy bleeding and cramping, as opposed to normal spotting, which occurs frequently in early pregnancy. This spotting can be caused by implantation or by the placenta "digging" its roots into the wall of the uterus. "But half the time, bleeding does indicate a miscarriage," says OB-GYN Henry Lerner, M.D. "It's a result of the fetus having died and the tissue starting to disintegrate. By the time you start bleeding, it's already done--it usually takes seven to 10 days to see any bleeding."
If you think you might be miscarrying, call your doctor. If you have in fact miscarried, he will want to make sure your body has completely expelled the tissue. If it hasn't, you may need a D and C, a minor surgical procedure, to remove it.
Later Miscarriage: What Are The Chances?
Occurring in less than 2 percent of pregnancies, miscarriages after the first trimester are most often caused by chromosomal abnormalities that "slip through," certain rarer hereditary chromosomal disorders that don't cause fetal death until late in pregnancy, or a so-called incompetent cervix. This is a condition in which the cervix cannot support a growing fetus; the weakening may be caused by previous surgery (such as for a precancerous condition) or by trauma from a previous delivery. It also can be congenital, says miscarriage expert Henry Lerner, M.D. Whatever the cause, a miscarriage resulting from an incompetent cervix usually occurs between 12 and 24 weeks of pregnancy. If you're diagnosed with cervical incompetence--and only about 1 in 500 women are--a small stitch may be inserted in your cervix to help keep it closed until delivery.