title: Second trimester placenta previa. An apparently normal placentation.
abstract: Placental positions in 214 patients scheduled for genetic amniocentesis were reviewed. Forty-five percent were found to have ultrasound findings of a low-lying placenta or partial or total placenta previa. At term, none of these patients required intervention for bleeding or placenta previa. Parity of 4 or more, but not age, correlated with an increased incidence of partial or total placenta previa, but not with a low-lying placenta. Low-lying placenta or placenta previa may be a normal variant in early pregnancy, suggesting that failure of the placenta to relinquish this position can result in an abnormally implanted placenta at term.
mesh_terms: D000328:Adult; D000649:Amniocentesis; D002902:Chromosomes, Human, 16-18; D002904:Chromosomes, Human, 21-22 and Y; D005260:Female; D006801:Humans; D008423:Maternal Age; D010298:Parity; D010923:Placenta Previa / Q000175:diagnosis*; D011247:Pregnancy; D011262:Pregnancy Trimester, Second; D014314:Trisomy; D014463:Ultrasonography