The effect of ethinyl estradiol 20 mcg and levonorgestrel 250 mcg on the pituitary-ovarian function during normal tablet-taking and when tablets are missed.

A new combined pill containing 20 micrograms of ethinyl estradiol and 250 micrograms of levonorgestrel has been developed. The safety margin of this type of low-dose preparation needed to be assessed and this was done by evaluating daily levels of LH, FSH, estradiol, progesterone, 1-NG and EE2 as well as cervical mucus characteristics in six patients when one and then two consecutive pills were deliberately omitted mid-way through the cycle. Results demonstrated that there was no evidence of breakthrough ovulation, although there was some continued ovarian steroidogenesis, a feature consistent with previous studies using combined preparations. Existing instructions to patients regarding missed pills should continue in order to ensure maximal contraceptive safety.

Studies on low dose oral contraceptives: plasma hormone changes in relation to deliberate pill ('Microgynon 30') omission.

PIP: The effects of deliberate omission of a Microgynon 30 (150 mcg of levonorgestrel and 30 mcg of ethinyl estradiol) tablet in the early and latter course of the pills were investigated by hormonal profiles (published figuratively) of luteinizing hormone, follicle stimulating hormone (FSH), estradiol 17-beta, and progesterone. 3 women deliberately missed Day 19, and blood samples were drawn from Day 17-24; 7 women deliberately omitted Day 4 treatment, and their blood was drawn from Day 1-7. Blood levels, contrary to previous findings which noted a sharp rise in FSH and near zero titers of steroids after omission of a Microgynon 30 tablet unintentionally, did not show any marked rise either early or late in the cycle omission. Cervical mucus examined in 6 of the subjects displayed physical characteristics associated with an uninterrupted ancillary contraceptive effect.^ieng