Woutersz T B, Butler A J, Cohen M, Korba V D, Canavan R C
Fertil Steril. 1987 Mar;47(3):425-30.
Controlled clinical investigations of a three-phase, low-dose oral contraceptive combination of levonorgestrel and ethinyl estradiol were conducted at 17 sites in the United States and 60 sites in the United Kingdom. A day 1 start in cycle one with no backup contraception was used. A total of 3546 female volunteers participated in 35,036 cycles. Medication was missed in 2688 (7.7%) cycles. Nine pregnancies were reported for an uncorrected use-effectiveness rate of 0.33 per 100 woman-years. Cycle control was excellent, bleeding irregularities were minimal, and the incidence of side effects was very low. No clinically significant variations in blood pressure means or weight means were observed. Carbohydrate and lipid metabolism studies were limited to 6 months and showed minimal alterations. Subject compliance with the preparation was excellent. It is concluded that this triphasic oral contraceptive with its varying ratios of levonorgestrel and ethinyl estradiol is an effective, predictable, and well-tolerated combination oral contraceptive.
一项关于左炔诺孕酮和炔雌醇三相低剂量口服避孕药组合的对照临床研究在美国的17个地点和英国的60个地点进行。采用在周期一开始时即开始服用且无后备避孕措施的方法。共有3546名女性志愿者参与了35036个周期。在2688个（7.7%）周期中出现漏服药物的情况。报告了9例妊娠，未校正的使用有效率为每100妇女年0.33例。周期控制良好，出血不规则情况极少，副作用发生率很低。未观察到血压均值或体重均值有临床显著变化。碳水化合物和脂质代谢研究仅限于6个月，显示变化极小。受试者对该制剂的依从性良好。结论是，这种左炔诺孕酮和炔雌醇比例不同的三相口服避孕药是一种有效、可预测且耐受性良好的复方口服避孕药。
