title: BMI as a modifying factor in the relations between age at menarche, menstrual cycle characteristics, and risk of preeclampsia.
abstract: To examine the relations between age at menarche and menstrual cycle characteristics and preeclampsia risk, we analyzed data from a case-control study conducted from 1998 to 2002. Usual menstrual cycle characteristics among 286 preeclampsia cases and 471 normotensive controls were assessed using a structured interview during postpartum hospitalization. We used multivariable logistic regression to estimate odds ratios (OR) and 95% confidence intervals (CI), adjusting for confounders. We also examined the influence of pre-pregnancy body mass index (BMI) on selected hypothesized relations. Among lean women (pre-pregnancy BMI < 25 kg/m(2)), preeclampsia risk was lower in those reporting cycles > or = 36 days in length (adjusted OR 0.78, CI 0.35-1.83) and menarche at > or = 14 years (adjusted OR 0.48, 95% CI 0.28-0.82). In contrast, among overweight or obese women, preeclampsia risk was higher in those with long cycles (OR 3.11, 95% CI 0.62-1.56, p(interaction) = 0.16) and late menarche (OR 1.53, 95% CI 0.59-3.97, p(interaction) = 0.03). These data suggest that adiposity influences the relations between usual menstrual cycle length, age at menarche, and preeclampsia. Overweight women with long cycles are at particularly high preeclampsia risk.
authors.affiliation: Department of Epidemiology, School of Public Health and Community Medicine, University of Washington, Seattle, 98122, USA. clb3@u.washington.edu
authors.forename: Carole L
authors.initials: CL
authors.lastname: Rudra
authors.forename: Michelle A
authors.initials: MA
authors.lastname: Williams
mesh_terms: D000367:Age Factors; D015992:Body Mass Index; D016022:Case-Control Studies; D016001:Confidence Intervals; D005260:Female; D006801:Humans; D016015:Logistic Models; D008572:Menarche / Q000502:physiology*; D008597:Menstrual Cycle / Q000502:physiology*; D009765:Obesity / Q000150:complications*; D016017:Odds Ratio; D011225:Pre-Eclampsia / Q000453:epidemiology* / Q000209:etiology; D011247:Pregnancy; D012307:Risk Factors; D013997:Time Factors