|Classification and external resources|
|ICD-10||O20, O46, O67, O72|
Obstetrical hemorrhage refers to heavy bleeding during pregnancy, labor, or the puerperium. Bleeding may be vaginal and external, or, less commonly but more dangerously, internal, into the abdominal cavity. Typically bleeding is related to the pregnancy itself, but some forms of bleeding are caused by other events. Obstetrical hemorrhage is a major cause of maternal mortality.
Antepartum hemorrhage 
Early pregnancy bleeding 
The most common bleeding event is the loss of a pregnancy, a miscarriage, medically also called a spontaneous abortion. Bleeding from an early miscarriage may be similar to that of a heavy menstruation, but later on, a pregnancy loss may be accompanied by excessive or prolonged bleeding. A physician may propose to perform a D&C for treatment. An ectopic pregnancy which implies a pregnancy outside the uterus commonly in the tube may lead to bleeding, internally, that could be fatal if untreated.
Late pregnancy bleeding 
The primary consideration is the presence of a placenta previa that is a low lying placenta, a condition that usually needs to be resolved by delivering the baby via cesarean section. Also a placental abruption (in which there is premature separation of the placenta )can lead to obstetrical hemorrhage, some times concealed.
Bleeding during labor 
Besides placenta previa and placental abruption, uterine rupture can occur as a very serious condition leading to internal or external bleeding. Bleeding from the fetus is rare, usually not heavy, but always very serious for the baby. This condition is called as Vasa Previa. Occasionally this condition can be diagnosed by ultrasound. There are also tests to differentiate maternal blood from fetal blood which can help in determining the source of the bleed.
Postpartum hemorrhage 
Hemorrhage after delivery, or postpartum hemorrhage, is the loss of greater than 500 ml of blood following vaginal delivery, or 1000 ml of blood following cesarean section. Other definitions of post partum haemorrhage are haemodynamic instability, drop of haemoglobin of more than 1 gm % or requiring blood transfusion.
See also 
- "Placenta praevia, placenta praevia accreta and vasa praevia: diagnosis and management" (pdf). January 2011. Retrieved 31 August 2012.