Obstetrical hemorrhage

Overview
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.

Early pregnancy bleeding
The most common bleeding event is the loss of a pregnancy, a miscarriage, medically also called an abortion. Bleeding from an early miscarriages may be similar to that of a heavy menstruation, but later on, a pregnancy loss may be accompanied but excessive or prolonged bleeding. A physician may propose to perform a D&C for treatment. An ectopic pregnancy may lead to bleeding, often internally, that could be fatal if untreated.

Late pregnancy bleeding
The primary consideration is the presence of a placenta previa, a condition that usually needs to be resolved by delivering the baby via cesarian section. Also a placental abruption can lead to obstetrical hemorrhage, some times concealed.

Bleeding during labor
Beside 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.

After delivery (Postpartum)
Trauma from the delivery may tear tissue and vessels leading to significant postpartum bleeding. Uterine atony refers to the inability of the uterus to contract and may lead to continuous bleeding. Retained placental tissue and infection may contribute to uterine atony (Bleeding from the birth canal >500mL after vaginal delivery and >1000mL after cesarean section delivery).

Differential Diagnosis of Causes of Postpartum Hemorrhage

 * Abruptio placentae
 * Cervical laceration
 * Chorioamnionitis
 * Disorders of coagulation
 * Drugs
 * Excessive uterine distension
 * Multiparity
 * Placenta accreta
 * Placenta previa
 * Rapid or prolonged labor
 * Retained placenta
 * Thrombocytopenia
 * Uterine inversion
 * Uterine rupture
 * Vaginal hematoma

Unrelated bleeding
Pregnant patients may have bleeding from the reproductive tract due to trauma, including sexual assault, neoplasm, most commonly cervical cancer, and hematologic disorders.

Management
The success of modern obstetrics is based to a good degree on the ability to recognize risk patients for obstetrical hemorrhage and their appropriate management. Key in this are methods of examination, including obstetric ultrasonography, surgical obstetrics, blood transfusion, and pharmacological support.