Comparison of ovarian follicular activity during treatment with a monthly injectable contraceptive and a low-dose oral contraceptive

Ovarian follicular development occurs during treatment with combined and progestin-only oral contraceptive (OC) pills and progestin-containing subdermal implants, and can be associated with the development of persistent functional cysts that may require surgical removal. Lunelle is a once-a-month injectable contraceptive containing estradiol cypionate 5 mg find medroxyprogesterone acetate 25 mg. A randomized, comparative study was undertaken to compare the effect on ovarian follicular activity associated with use of Lunelle and a low-dose OC. A total of 30 ovulatory subjects were randomly assigned to receive two cycles of treatment with either an OC containing ethinyl estradiol 20 mu g find 0.1 mg levonorgestrel or Lunelle. During the second cycle of treatment, pelvic sonography was performed every 4 days, at which time the maximum follicle diameter was measured. Study end points were the presence of follicles greater than or equal to 10, 20, and 30 mm. In all, 13 of 15 subjects in the OC group and 14 of 25 in the Lunelle group completed the study. Follicles measuring greater than or equal to 10 mm were present in 11 of 13 (84.6%) in the OC users and in four of 14 (28.6%) in the Lunelle users (p < 0. 05). In the OC group, six of 13 subjects (46.1%) developed follicles greater than or equal to 20 mm, and one of 13 (7.7%) developed follicles greater than or equal to 30 mm. No subjects in he Lunelle group developed a follicle greater than or equal to 20 mm in diameter. This study indicates that Lunelle is associated with a significantly lower incidence of ovarian follicular development compared to that of an OC containing 20 mu g ethinyl estradiol and 0.1 mg levonorgestrel. CONTRACEPTION 2000;61:195-198 (C) 2000 Elsevier Science Inc. All rights reserved.