Anencephaly and twins.
MacMahon
Brian
B
Rothman
Kenneth J
KJ
D000757:Anencephaly / Q000453:epidemiology*; D004200:Diseases in Twins / Q000453:epidemiology*; D005260:Female; D005307:Fertilization in Vitro; D006801:Humans; D011247:Pregnancy; D011272:Pregnancy, Multiple