Abstract :
Two major causes for thirdtrimester antepartum hemorrhage include the following: • Placenta previa: encroachment of the placenta on the internal cervical os. • Abruptio placenta: premature separation of the placenta from the wall of the uterus. The absence of pain is often regarded as a significant distinguishing factor between placenta previa and placental abruption. Typically, placenta previa presents as a painless vaginal bleeding without uttering hyperactivity or tenderness. In contrast, bleeding from an abruptio placenta can be witnessed per vagina or remain concealed and is often accompanied by contractions. Placenta previa and abruptio placenta account for one half to two thirds of all cases of antepartum hemorrhage; cervical pathology, polyps, carcinoma, vaginal and valvular varicosities, circumvallate placenta, and vasa previa cause the remainder. All vaginal bleeding in the third trimester should be considered placenta previa until proven otherwise.
