Letter: Spontaneous abortion and neural tube defects.
D000022:Abortion, Spontaneous / Q000453:epidemiology*; D000757:Anencephaly / Q000453:epidemiology*; D005260:Female; D006801:Humans; D008499:Medical Records; D011247:Pregnancy; D012923:Social Class; D016135:Spinal Dysraphism / Q000453:epidemiology*