Early low-lying placentae--ultrasonic assessment, progress and outcome.
A prospective study was carried out using 100 patients with 64 appropriately matched controls, to follow the course of low-lying placentae, diagnosed before 20 wk gestation. 94% of these placentae had moved out of the lower segment by the 32nd wk, while only 2% of the total required a caesarean section for placenta praevia. No evidence of intrauterine growth retardation or increased incidence of preeclampsia was found. In the light of this and other studies, a routine ultrasound re-check of placental position subsequent to 32 wk is deemed unnecessary unless clinically indicated, saving unnecessary maternal anxiety and over-exposure to ultrasound. Since the posterior low-lying placentae are those more likely to remain praevia, it is they that require follow-up scans.
D000293:Adolescent; D000328:Adult; D002585:Cesarean Section; D005260:Female; D005317:Fetal Growth Retardation / Q000209:etiology; D006801:Humans; D010923:Placenta Previa / Q000175:diagnosis* / Q000209:etiology / Q000601:surgery; D011247:Pregnancy; D011262:Pregnancy Trimester, Second; D011263:Pregnancy Trimester, Third; D014463:Ultrasonography