Keywords combined oral contraceptives;intrauterine device;stroke;prospective cohort study;case control study;genetics;angiotensinogen;angiotensiongen converting enzyme;

• 复方口服避孕药;宫内避孕器;脑卒中;前瞻性研究;病例-对照研究;基因;血管紧张素原;血管紧张素转换酶;