title: Ultrasound and human-placental-lactogen screening early detection of twin pregnancies.
abstract: In the past five years gradual introduction of ultrasonic screening of pregnant women increased the ante-partum detection of multiple pregnancy from 60% in 1971 to 95% in the first half of 1975. At the same time the average gestational age for dection of multiple pregnancies diminished from thirty-three to twenty-five weeks. The corresponding figures for 1963 were 32% and thirty-six weeks. Plasma human-placental-lactogen concentrations were assessed for their value in selecting a smaller target group for subsequent ultrasonic screening. All but 2 of 39 twin pregnancies examined by single H.P.L. determinations had H.P.L. values more than 1 S.D. above the mean of the normal distribution. The use of plasma-H.P.L. screening might lower the proportion of patients requiring ultrasonography for antepartum diagnosis of multiple pregnancies to 16% of the total pregnant population.
mesh_terms: D005069:Evaluation Studies as Topic; D005260:Female; D005865:Gestational Age; D006801:Humans; D010928:Placental Lactogen / Q000097:blood*; D011247:Pregnancy; D011263:Pregnancy Trimester, Third; D011272:Pregnancy, Multiple; D011296:Prenatal Diagnosis / Q000379:methods*; D013548:Sweden; D014427:Twins; D014463:Ultrasonography
chemical_list: D010928:Placental Lactogen