While COCs containing 20 μg EE may be theoretically safer, this review did not focus on the rare events required to assess this hypothesis. Data from existing randomized controlled trials are inadequate to detect possible differences in contraceptive effectiveness. Low-dose estrogen COCs resulted in higher rates of bleeding pattern disruptions. However, most trials compared COCs containing different progestin types, and changes in bleeding patterns could be related to progestin type as well as estrogen dose. Higher follow-up rates are essential for meaningful interpretation of results.
Comparison of a novel norgestimate/ethinyl estradiol oral contraceptive (Ortho Tri-Cyclen Lo) with the oral contraceptive Loestrin Fe 1/20.
This multicenter study compared the contraceptive efficacy, cycle control, and safety of a new triphasic norgestimate (180/215/250 microg)/ethinyl estradiol 25 microg regimen (Ortho Tri-Cyclen Lo) (n = 1,723) with that of norethindrone acetate 1 mg/ethinyl estradiol 20 microg (Loestrin Fe 1/20) (n = 1,171). Healthy women were treated for up to 13 cycles. Demographics were similar between regimens. Contraceptive efficacy was comparable for Ortho Tri-Cyclen Lo and Loestrin Fe 1/20. The overall and method failure probabilities of pregnancy through 13 cycles were 1.9% and 1.5%, respectively, with Ortho Tri-Cyclen Lo and 2.6% and 2.4%, respectively, with Loestrin Fe 1/20. Breakthrough bleeding and spotting was reported by a significantly lower percentage of participants in the Ortho Tri-Cyclen Lo group compared with the Loestrin Fe 1/20 group. At representative Cycles 1, 3, 6, 9, and 13, breakthrough bleeding and spotting rates were 16.3, 11.5, 10.3, 7.9, and 7.7%, respectively, in the Ortho Tri-Cyclen Lo group and 34.9, 22.9, 22.2, 15.9, and 13.1%, respectively, in the Loestrin Fe 1/20 group. Compliance and safety data were similar for the two regimens.