Fetal chromosomal aneuploidies and maternal serum alpha-fetoprotein levels in first trimester.
D000782:Aneuploidy; D002824:Chorionic Villi / Q000648:ultrastructure; D005260:Female; D005333:Fetus; D006801:Humans; D011247:Pregnancy; D011261:Pregnancy Trimester, First; D011296:Prenatal Diagnosis; D000509:alpha-Fetoproteins / Q000032:analysis*
D000509:alpha-Fetoproteins