Oestrogens in the pill.
D000029:Abortion, Legal; D003267:Contraception; D003276:Contraceptives, Oral / Q000009:adverse effects*; D004967:Estrogens / Q000009:adverse effects*; D005260:Female; D006801:Humans; D011247:Pregnancy; D013923:Thromboembolism / Q000139:chemically induced / Q000453:epidemiology
D003276:Contraceptives, Oral; D004967:Estrogens