Coital frequency and contraception.
D000328:Adult; D000367:Age Factors; D003075:Coitus; D003267:Contraception; D003276:Contraceptives, Oral; D005260:Female; D005298:Fertility; D006801:Humans; D007434:Intrauterine Devices; D008393:Marriage; D011247:Pregnancy; D012309:Risk-Taking; D013223:Statistics as Topic; D013245:Sterilization, Reproductive; D014481:United States; D014659:Vasectomy
D003276:Contraceptives, Oral