Peripheral placental separation: a review.

Marginal placental bleeding is a distinct entity, marked (usually) by minor degrees of vaginal bleeding and significantly associated with premature labor and premature rupture of the membranes. Pathologically it is characterized by an adherent marginal placental hematoma, which shows varying degrees of film deposition and leukocytic infiltration depending on the age of the clot. Marginal placental bleeding may occur only once or be repeated many times. It usually is not fatal to mother or fetus per se. The chief clinical significance of the marginal placental bleed is its tendency to be confused with placenta previa. The perinatal mortality associated with perpheral placental separation is largely that of prematurity.