Significance of the ultrasound location of placental site in early pregnancy.
The placenta was located by routine ultrasound scanning before 24 weeks gestation in 615 consecutive obstetric patients. A 'low lying' placenta was present in 175 (28 per cent) of the total group; the incidence decreasing from 32 per cent at 16 weeks gestation to 18 per cent at 24 weeks. Of 94 women with an initial 'low lying' placenta who were selected for rescanning, only five had a placenta praevia persisting beyond the 34th week. Patients with an early 'low lying' placenta had a significantly higher incidence of small-for-dates babies than those in whom the placenta remained clear of the internal cervical os on ultrasound scanning.
D005260:Female; D005333:Fetus / Q000033:anatomy & histology; D006801:Humans; D007231:Infant, Newborn; D007236:Infant, Small for Gestational Age; D010920:Placenta / Q000033:anatomy & histology*; D011247:Pregnancy; D011248:Pregnancy Complications / Q000175:diagnosis; D011261:Pregnancy Trimester, First; D011262:Pregnancy Trimester, Second; D014463:Ultrasonography