Extending the duration of the pill-free interval during combined oral contraception

Adv Contracept. 1990 Mar;6(1):33-40. doi: 10.1007/BF01849485.


The effect of increasing the duration of the pill-free interval from 7 to 9 and 11 days during the first 4 months of combined oral contraceptive therapy was studied by hormonal, ovarian follicle and mucus changes. Increasing the pill-free interval allowed more follicular development and more estradiol production. In some cases, pre-ovulatory values were achieved although ovulation did not occur. No differences could be detected between different types of combined oral contraceptive, including monophasic, triphasic, levonorgestrel-containing and gestodene-containing. The variation between individuals in the group of 28 was far greater than any variation in dose.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Analysis of Variance
  • Cervix Mucus / drug effects
  • Cervix Mucus / physiology
  • Contraceptives, Oral, Combined / administration & dosage*
  • Drug Administration Schedule
  • Estradiol / biosynthesis
  • Female
  • Follicular Phase / physiology*
  • Humans


  • Contraceptives, Oral, Combined
  • Estradiol