Coital frequency, delayed fertilization, and outcome of pregnancy.
D003075:Coitus; D004314:Down Syndrome / Q000209:etiology; D005260:Female; D005306:Fertilization; D005313:Fetal Death / Q000453:epidemiology; D006801:Humans; D007226:Infant Mortality; D007231:Infant, Newborn; D007234:Infant, Premature; D008423:Maternal Age; D010060:Ovulation; D011247:Pregnancy; D013997:Time Factors