Testing the "rest" hypothesis on anencephaly and spina bifida.
D000022:Abortion, Spontaneous / Q000209:etiology* / Q000235:genetics; D000757:Anencephaly / Q000150:complications*; D005260:Female; D006801:Humans; D011247:Pregnancy; D012107:Research Design; D016136:Spina Bifida Occulta / Q000150:complications*