Among the most common causes of a hemorrhage during pregnancy are miscarriage and leftover tissue after a miscarriage. In some cases, excessive bleeding may develop because of problems with the placenta. Other possible causes include premature labor and retention of a dead fetus in the womb. Uterine rupture may also contribute to hemorrhaging, but it is much less common than other causes.
One common cause of hemorrhaging during pregnancy is a miscarriage. This may occur, for example, when a pregnancy loss has occurred and the body is attempting to expel tissue or clots left in the woman’s uterus. Hemorrhaging may also occur because tissue remaining in the uterus after a pregnancy lead to an infection.
Sometimes a hemorrhage during pregnancy is the result of problems with the placenta. For example, the placenta may tear partially or entirely away from the uterine wall and cause excessive bleeding. Unfortunately, this condition, which is referred to as placental abruption, can threaten the lives of the unborn child and the mother. Additionally, a woman may experience a hemorrhage during pregnancy not because the placenta has torn away from the wall of the uterus, but because the placenta is abnormally positioned within the uterus. This condition, called placenta previa, occurs when the placenta is positioned over the opening of the uterus.
The death of an unborn baby may also lead to hemorrhage during pregnancy. This cause is most likely to occur in the first trimester of pregnancy. It is not a common cause of hemorrhaging during the second or third semester of pregnancy, though it may occur occasionally.
Premature labor may also cause hemorrhage during pregnancy. Premature labor begins before the 37th week of pregnancy, the point a pregnancy is considered full term. The average full-term pregnancy lasts for about 40 weeks. Many women have premature labor and do not experience hemorrhaging. In some cases, however, a problem within the uterus leads to excessive bleeding. This may occur, for example, if problems existed with the placenta or if abnormal growths are present inside the womb.
Uterine rupture is also among the possible causes of hemorrhage during pregnancy. It occurs when the uterus splits open and causes the baby to move into the mother’s abdomen. Fortunately, it is not as common as other issues that cause excessive bleeding during pregnancy. When uterine rupture does occur, however, it puts the fetus and the mother in serious danger.