title: 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.
abstract: 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.
mesh_terms: D000293:Adolescent; D000328:Adult; D003276:Contraceptives, Oral / Q000494:pharmacology*; D003277:Contraceptives, Oral, Combined / Q000008:administration & dosage / Q000494:pharmacology*; D004997:Ethinyl Estradiol / Q000494:pharmacology*; D005260:Female; D006065:Gonadotropins, Pituitary / Q000097:blood; D006801:Humans; D016912:Levonorgestrel; D008598:Menstruation; D009644:Norgestrel / Q000008:administration & dosage*; D010053:Ovary / Q000187:drug effects*; D010902:Pituitary Gland / Q000187:drug effects*; D011374:Progesterone / Q000097:blood
chemical_list: D003276:Contraceptives, Oral; D003277:Contraceptives, Oral, Combined; D006065:Gonadotropins, Pituitary; D009644:Norgestrel; D004997:Ethinyl Estradiol; D011374:Progesterone; D016912:Levonorgestrel