Changing oral contraceptives.
D003276:Contraceptives, Oral / Q000009:adverse effects*; D004967:Estrogens / Q000009:adverse effects*; D005260:Female; D006261:Headache / Q000139:chemically induced; D006801:Humans; D011247:Pregnancy; D011372:Progestins / Q000009:adverse effects; D013923:Thromboembolism / Q000139:chemically induced; D013924:Thrombophlebitis / Q000139:chemically induced
D003276:Contraceptives, Oral; D004967:Estrogens; D011372:Progestins