Pregnancy and the timing of intercourse.
D000328:Adult; D000367:Age Factors; D015331:Cohort Studies; D003075:Coitus; D005260:Female; D005306:Fertilization / Q000502:physiology*; D006801:Humans; D008297:Male; D010060:Ovulation; D011247:Pregnancy; D012744:Sex Ratio; D013094:Spermatozoa; D013997:Time Factors