Prenatal diagnosis of neural tube defects. III. A reevaluation of the alpha-fetoprotein assay.
Alpha-fetoprotein was measured in 2209 amniotic fluid samples under improved assay conditions. All cases of open neural tube defects had elevated values greater than 5 SD above the mean. The false positive rate based on the 3 SD cutoff is estimated at less than 9.15%. Alpha-fetoprotein assays are recommended for all patients undergoing second trimester amniocentesis, optimally between 14 and 16 weeks' gestation.
D000328:Adult; D000653:Amniotic Fluid / Q000032:analysis*; D001921:Brain / Q000002:abnormalities; D005189:False Positive Reactions; D005260:Female; D005312:Fetal Blood / Q000032:analysis; D005865:Gestational Age; D006801:Humans; D009420:Nervous System / Q000196:embryology; D009421:Nervous System Malformations; D011247:Pregnancy; D011296:Prenatal Diagnosis; D013116:Spinal Cord / Q000002:abnormalities; D000509:alpha-Fetoproteins / Q000032:analysis*
D000509:alpha-Fetoproteins