Eyong E, Priddy A R, Killick S R, Elstein M
Department of Obstetrics and Gynaecology, University Hospital of South Manchester, UK.
Adv Contracept. 1989 Mar;5(1):1-11. doi: 10.1007/BF02340127.
This study was prompted by the various recommendations given by different oral contraceptive manufacturers to women who wish to switch from a monophasic to a triphasic formulation. Ten women who switched from a variety of monophasic pills to a levonorgestrel triphasic pill formulation after a 7-day pill-free interval were studied. Follicular maturation was monitored by ultrasound scan, and the levels of serum follicle stimulating hormone (FSH), luteinizing hormone (LH), progesterone (P) and estradiol (E2) measured. Pituitary-ovarian activity was suppressed in six of the ten women studied, while in the remaining four women there was some pituitary-ovarian activity during the first 10 days on the triphasic pill. These findings suggest a shorter pill-free interval, as advised in USA data sheets, may be less likely to result in pill failures when women switch from a monophasic to a triphasic preparation.
本研究是受不同口服避孕药制造商向希望从单相制剂改用三相制剂的女性给出的各种建议所推动。对10名在停药7天后从各种单相避孕药改用左炔诺孕酮三相避孕药制剂的女性进行了研究。通过超声扫描监测卵泡成熟情况，并测定血清促卵泡生成素（FSH）、促黄体生成素（LH）、孕酮（P）和雌二醇（E2）水平。在研究的10名女性中，有6名女性的垂体-卵巢活动受到抑制，而在其余4名女性中，在服用三相避孕药的前10天内有一些垂体-卵巢活动。这些发现表明，如美国药品说明书中所建议的，较短的停药间隔在女性从单相制剂改用三相制剂时可能不太可能导致避孕失败。
