Abstract

Abstract Background Associations between early‐life menstrual cycle characteristics (MCC) and gestational diabetes (GDM) remain unclear. Objectives To evaluate associations between early‐life MCCs and GDM in first pregnancy, across pregnancies and its recurrence. Methods This analysis included participants from a US‐based digital cohort enrolled between 11/2019 and 9/2023 who provided consent, completed relevant surveys, were without diabetes and aged ≥18 at first pregnancy ( n = 30,473). Age at menarche [<11 (early), 11–15 (referent), ≥16 (late) years] and time from menarche to cycle regularity [<1 (referent), 1–2, 3–4, ≥5 years, not yet regular, regular after hormones] were self‐recalled at enrolment. Additionally, the last three categories were considered prolonged time‐to‐regularity (PTTR). GDM history was recalled at enrolment for each pregnancy. We restricted to pregnancies of ≥24 weeks with a live birth. We evaluated associations of early‐life MCCs with GDM at first pregnancy using modified Poisson regression, across pregnancies using cluster‐weighted Poisson generalised estimating equation and GDM recurrence using multinomial logistic regression, adjusted for sociodemographic, early‐life factors and age at pregnancy. Missing variables were imputed with multiple imputation by chained equations. Results Among 30,473 participants, 20,591 had eligible first pregnancies, of which 5.9% reported GDM. In 17,512 participants with ≥2 pregnancies, 8.3% had GDM once and 3.7% had recurrent GDM. Early menarche (<11 years, vs. 11–15 years) was associated with GDM in first pregnancy (RR 1.34, 95% CI 1.15, 1.57), across pregnancies (RR 1.24, 95% CI 1.10, 1.39) and recurrence (OR 1.51, 95% CI 1.21, 1.89). PTTR was associated with GDM in the first pregnancy (RR 1.22, 95% CI 1.08, 1.38), across pregnancies (RR 1.16, 95% CI 1.05, 1.27) and recurrence (OR 1.19, 95% CI 0.99, 1.43). Conclusions Earlier menarche and prolonged time‐to‐regularity are associated with higher risk of GDM and recurrence, suggesting menstrual characteristics during childhood/adolescence as potential early‐life markers for GDM.