A miscarriage is a loss of the fetus that occurs during the first 24 weeks of the pregnancy--beyond this point, it is called fetal demise or still birth. Usually one of the first signs of an impending miscarriage is vaginal bleeding, especially if this bleeding is very heavy or you pass clots.
According to the website of the British health-car company Bupa, miscarriages are most likely to happen during the first 12 weeks of pregnancy. This often happens because there are problems with the fetus that would have prevented it from growing or developing normally.
Symptoms of a miscarriage include vaginal bleeding and menstrual-type cramps. Some women have vaginal spotting or bleeding during a normal pregnancy, but it usually remains light. Bleeding that includes clots or solid grayish tissue is more likely to be due to a miscarriage.
Vaginal bleeding or spotting comes in different colors. Brown blood indicates the blood is old, as may happen with a missed miscarriage. Red blood is recent; if there is a lot of it you should go to an emergency room. Pink and light brown both mean that there is not a lot of blood. Gray or yellowish clots are often fetal tissue.
If you are pregnant and experience any vaginal bleeding, call your doctor immediately. If you know you are miscarrying, you should also call your doctor if you pass any large blood clots.
About half of women who experience vaginal bleeding during early pregnancy carry the baby to term, according to the website of Shands HealthCare in Florida. Women who do miscarry are usually able to have children in the future.