title: Length of the menstrual cycle after discontinuation of oral contraceptives.
abstract: OBJECTIVE
  To investigate whether the first cycle after stopping oral contraceptive (OC) intake had a normal duration.
  
  
  METHODS
  A retrospective study was performed in 680 women, 300 non-OC users and 380 women discontinuing OC intake. The length of one or two menstrual cycles was recorded.
  
  
  RESULTS
  In the non-user group, the median duration of both the first and second cycle was 29 days (range 18-97 and 20-56 days, respectively). In the OC user group the median duration from withdrawal bleeding until next menstruation was 30 (15-82) days. The second cycle lasted 29 (17-122) days. The duration of the first post-treatment cycle was not significantly different from the next cycle or the cycle length in non-users. When the subjects were divided into different age categories, a significantly longer first post-treatment cycle was observed in the group aged 18-24 years, but a shorter first post-treatment cycle in the group aged 25-29 years. No differences were seen in the higher age groups. The ethinyl estradiol dose of the OC preparation did not influence the results.
  
  
  CONCLUSIONS
  The first cycle after OC discontinuation had a normal duration.
authors.affiliation: Dinox Medical Investigations, Nijmengen, The Netherlands. iduijkers@dinoxgroup.com
authors.forename: Ingrid
authors.initials: I
authors.lastname: Duijkers
authors.forename: Lonneke
authors.initials: L
authors.lastname: Engels
authors.forename: Christine
authors.initials: C
authors.lastname: Klipping
mesh_terms: D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D000568:Amenorrhea / Q000139:chemically induced / Q000453:epidemiology; D003277:Contraceptives, Oral, Combined / Q000008:administration & dosage / Q000009:adverse effects; D005260:Female; D006801:Humans; D008597:Menstrual Cycle / Q000187:drug effects; D009426:Netherlands / Q000453:epidemiology; D012189:Retrospective Studies
chemical_list: D003277:Contraceptives, Oral, Combined