“Most (60% to 80%) women experience hot flashes during the menopausal transition,” Rhoda J. Conant, MD, of the University of Oklahoma Health Science Center, and colleagues wrote in an abstract. “[Hot flashes] have been associated with vascular endothelial dysfunction beyond standard cardiovascular disease risk factors and estradiol. Hypertensive disorders in pregnancy and gestational diabetes mellitus are associated with vascular and endothelial dysfunction. Given a similar pathophysiology, we hypothesize that women with a history of [hypertensive disorders of pregnancy] and [gestational diabetes] may experience a greater burden of [hot flashes]. We further hypothesize that nulliparous women may have fewer [hot flashes].”
Conant and colleagues analyzed data from 2,249 women who completed a pregnancy history questionnaire at the 13th visit of the Study of Women’s Health Across the Nation (SWAN) study. Researchers stratified women as nulliparous, no hypertensive disorders of pregnancy or gestational diabetes, or having a history of hypertensive disorders of pregnancy or gestational diabetes. Researchers assessed hot flashes at baseline and at each of the 13 follow-up visits over 15 years. Women who underwent hysterectomy/oophorectomy and those prescribed hormone therapy were excluded.
Hot flash frequency was classified as any vs. none; 0 days, 1 to 5 days, or at least 6 days in the past 2 weeks. Participant characteristics were compared across exposure groups using analysis of variance or Kruskal-Wallis tests for continuous data and chi-square or Fisher’s exact tests for categorical variables.
Pregnancy history was examined in relation to hot flash frequency using generalized estimating equations adjusting for race, financial strain, education, study site and menopausal stage.
At time of the pregnancy questionnaire, mean age of women was 61 years. Within the cohort, 395 (17.6%) were the nulliparous group, 1,646 (73.2%) were parous women without hypertensive disorders of pregnancy or gestational diabetes, and 208 women (9.2%) were parous with hypertensive disorders of pregnancy or gestational diabetes.
Among women with previous gestational diabetes or hypertension, 176 (85%) had preeclampsia only, 27 women (13%) had gestational diabetes, and five women (2%) reported both conditions.