Letter: Neural-tube defects.
D002490:Central Nervous System / Q000002:abnormalities* / Q000196:embryology; D002675:Child, Preschool; D002869:Chromosome Aberrations; D025063:Chromosome Disorders; D002903:Chromosomes, Human, 19-20; D002905:Chromosomes, Human, 4-5; D000013:Congenital Abnormalities / Q000453:epidemiology; D005260:Female; D006801:Humans; D007223:Infant; D014481:United States