title: Age at menarche, menstrual cycle characteristics and risk of gestational diabetes.
abstract: OBJECTIVE
  We examined associations of age at menarche and menstrual cycle characteristics with gestational diabetes mellitus (GDM) risk.
  
  
  METHODS
  Study participants (N=3490) recruited prior to 16 weeks of gestation were followed until delivery. Menstrual history data were collected using questionnaires. GDM was diagnosed using the American Diabetes Association 2003 guidelines. Logistic regression was used to estimate odds-ratios (OR) and 95% confidence intervals (CI).
  
  
  RESULTS
  Age at menarche was not associated with GDM risk. Women who had long menstrual cycles (>36 days) had higher risk of GDM compared with women who had normal cycle length (25-30 days) (OR=1.6; 95%CI0.98-2.67). Women who had long menstrual cycles and were either overweight or gained >5kg in adulthood had 4-5-fold higher GDM risk compared with women who had normal cycle length and were non-obese or gained <5kg in adulthood, respectively (OR=4.03; 95%CI:2.08-7.81 and OR=4.62, 95%CI:2.65-8.07, respectively).
  
  
  CONCLUSIONS
  Longer menstrual cycles are significantly associated with increased risk of GDM, particularly among women who were either overweight or obese pre-pregnancy, or had ≥5kg weight gain in adult hood. Menstrual history may help identify women with increased risk of GDM.
authors.affiliation: Center for Perinatal Studies, Swedish Medical Center, Seattle, WA, USA. Michal.Dishi-galitzky@swedish.org
authors.forename: Michal
authors.initials: M
authors.lastname: Dishi
authors.forename: Daniel A
authors.initials: DA
authors.lastname: Enquobahrie
authors.forename: Dejene F
authors.initials: DF
authors.lastname: Abetew
authors.forename: Chunfang
authors.initials: C
authors.lastname: Qiu
authors.forename: Carole B
authors.initials: CB
authors.lastname: Rudra
authors.forename: Michelle A
authors.initials: MA
authors.lastname: Williams
mesh_terms: D000328:Adult; D016001:Confidence Intervals; D016640:Diabetes, Gestational / Q000453:epidemiology*; D005260:Female; D006801:Humans; D016015:Logistic Models; D008572:Menarche / Q000502:physiology*; D008597:Menstrual Cycle / Q000502:physiology*; D016017:Odds Ratio; D011247:Pregnancy; D012307:Risk Factors; D055815:Young Adult