title: Menstrual reduction with extended use of combination oral contraceptive pills: randomized controlled trial.
abstract: OBJECTIVE
  To compare a traditional 28-day cycle to an extended 49-day cycle of the 30 microg ethinyl estradiol (E2)/300 microg norgestrel monophasic birth control pill regimen.
  
  
  METHODS
  Ninety subjects randomized to either 28-day cycles with 21 active pills or 49-day cycles with 42 active pills for a prospective open label trial over four 84-day reference periods or trimesters. Bleeding, pill taking, and symptom diaries were completed. The sample size with 80% power to detect a 40% reduction in bleeding days required 24 subjects in each arm.
  
  
  RESULTS
  Of the 90 women, 24 subjects (54.5%) on the 28-day cycle and 29 (63%) on the 49-day cycle completed the entire study (P =.41). There were no statistically significant differences between the two groups in demographics or continuation rates. There was a significant reduction in bleeding days in the experimental arm beginning in the first trimester (28-day = 10.9, 49-day = 6.4 mean days of bleeding, P <.001) and continuing to the fourth trimester (28-day = 11.3, 49-day = 5.8 mean days, P =.005). The number of spotting days was similar between both schedules in the first trimester (28-day = 4.8, 49-day = 3.7 mean days, P =.24) and continued into the fourth trimester (28-day = 3.4, 49-day = 2.9 mean days, P =.30). Annual expenditure for hygiene products was significantly less for extended use subjects (28-day = $41.45, 49-day = $17.54 spent, P <.001).
  
  
  CONCLUSIONS
  Extension of the 28-day oral contraceptive (OC) cycle to a 49-day cycle resulted in fewer bleeding days and no increase in mean spotting days or bleeding episodes.
authors.affiliation: Department of Obstetrics and Gynecology, University of Washington School of Medicine, Seattle, Washington, USA. lmiller@u.washington.edu
authors.forename: L
authors.initials: L
authors.lastname: Miller
authors.forename: K M
authors.initials: KM
authors.lastname: Notter
mesh_terms: D000328:Adult; D003277:Contraceptives, Oral, Combined / Q000008:administration & dosage; D004334:Drug Administration Schedule; D019304:Ethinyl Estradiol-Norgestrel Combination / Q000008:administration & dosage; D005260:Female; D006801:Humans; D008598:Menstruation / Q000187:drug effects*; D011446:Prospective Studies; D013997:Time Factors
chemical_list: D003277:Contraceptives, Oral, Combined; D019304:Ethinyl Estradiol-Norgestrel Combination