Introduction: Identification of women at high risk of gestational diabetes mellitus (GDM) at an early life stage may allow early health monitoring and intervention. A younger age at menarche has been associated with increased risk of type 2 diabetes, but the association with GDM remains unclear.
Objective: To examine the association between age at menarche and development of GDM in a population-based study of reproductive-aged Australian women.
Methods: Over a follow-up period of 12 years, 4,749 women participating in the Australian Longitudinal Study on Women’s Health reported at least one pregnancy. GDM diagnosis was self-reported for each pregnancy and validated in a subsample. Age at menarche was reported at baseline in 2000 when the women were aged 22-27 years. Log-binomial regression analysis was used to estimate relative risks (RR) and 95% confidence intervals (CI).
Results: A first diagnosis of GDM was reported by 357 women (7.5%). Mean age at menarche was 13 years (SD 1.4). Compared with women with menarche at age 13 years, women who had their first menstruation at age 11 or younger had a 65% higher risk of developing GDM (95% CI 1.20, 2.25) after adjustment for education, parity, polycystic ovary syndrome and physical activity. This higher risk was attenuated by 14% (OR 1.51, 95% CI 1.10, 2.07) after additional adjustment for pre-pregnancy BMI.
Conclusions: Findings from this population-based study of Australian women suggest that a history of early menarche may be clinically useful to identify women at higher risk of developing GDM. Moreover, results indicate that avoiding overweight and obesity in women with early menarche may lower their risk of GDM. Further birth cohort studies are needed to elucidate the role of early life exposures and weight trajectories on age at menarche and subsequent GDM risk.