title: Evaluation of measurement of maternal plasma alpha-fetoprotein levels as a screening test for fetal neural tube defects.
abstract: Maternal plasma alpha-fetoprotein (AFP) levels were estimated on 1844 consecutive patients at the time of their first hospital antenatal visits. There were 28 pregnancies with an 'abnormal' outcome: 19 patients had twins, 3 had an anencephalic fetus, and 6 a fetus with a spina bifida (4 of these had an open neural tube defect). Evaluation of maternal plasma AFP levels as a screening test for neural tube defects at 15 to 19 weeks gestation indicated a sensitivity of 50% taking the 'cut-off' point as the 95th centile of the plasma AFP levels in pregnancy with a normal outcome.
mesh_terms: D000757:Anencephaly / Q000175:diagnosis*; D005260:Female; D005315:Fetal Diseases / Q000175:diagnosis*; D006801:Humans; D009420:Nervous System / Q000196:embryology; D011247:Pregnancy; D011262:Pregnancy Trimester, Second; D011272:Pregnancy, Multiple; D016135:Spinal Dysraphism / Q000175:diagnosis*; D000509:alpha-Fetoproteins / Q000032:analysis*
chemical_list: D000509:alpha-Fetoproteins