Associations Between Prepregnancy Menstrual Characteristics, Age at Menarche, and the Risk of Gestational Diabetes Mellitus: A Matched Case-Control Study.

BACKGROUND

Inconsistencies exist in the literature regarding the associations among age at menarche (AAM), prepregnancy menstrual characteristics, and the risk of gestational diabetes mellitus (GDM). These discrepancies may be attributable to variations in population demographics. The aim of this study was to investigate the impact of prepregnancy menstrual characteristics and AAM on the likelihood of developing GDM among Chinese women.

METHODS

A 1:1 age-matched case-control study was conducted that included 2289 patients with GDM and 2289 normoglycemic pregnant women as controls at Wuhan Union Hospital from September 2020 to August 2022. Fasting blood samples were collected during 24-28 weeks of gestation. AAM and menstrual cycle characteristics were categorized and incorporated into a conditional logistic regression model that was adjusted for potential confounders. Additionally, restricted cubic spline curves were employed to assess the trend in GDM risk associated with AAM.

RESULTS

The final analysis included 4578 participants. The AAM in the GDM group presented significantly earlier than that in the normoglycemic group (p < 0.05). After adjusting for confounding factors, we found that women with an AAM of 12 years (aOR = 1.44, 95% CI: 1.25-1.67) or 14 years (aOR = 1.36, 95% CI: 1.15-1.61) had a significantly higher risk of developing GDM compared with those with an AAM of 13 years. Furthermore, analysis of the data by means of restricted cubic splines revealed an L-shaped association that linked AAM to GDM (p < 0.001). The association between prolonged and irregular menstrual cycles and GDM risk remained statistically significant, albeit attenuated, after multivariable adjustment. Irregular menstrual cycles (classified as "usually irregular" or "always irregular") were significantly associated with an increased risk of GDM, with aORs of 2.36 (95% CI: 1.47-3.79) and 2.40 (95% CI: 1.01-5.71), respectively. Moreover, menstrual cycle durations of 32-39 days or more than 50 days were significantly associated with an increased risk of GDM (aORs: 1.20 and 1.37; 95% CIs: 1.10-1.41 and 1.03-1.83, respectively).

CONCLUSION

Early AAM, irregular menstrual cycles, and prolonged menstrual cycle length were associated with an increased risk of GDM. Among women with menarche occurring before the age of 13, there was an association with a higher risk of GDM. These indicators may help identify women at high risk and facilitate preconception interventions to prevent GDM.

TRIAL REGISTRATION: ClinicalTrials.gov identifier: ChiCTR2200063189.