Impact of fetal gender on gestational diabetes mellitus' incidence: A cohort study

Introduction: Gestational diabetes mellitus (GDM) is a prevalent metabolic disorder in pregnancy, associated with maternal and neonatal complications. While established risk factors are well-documented, the potential role of fetal gender on GDM development remains uncertain. The present study aimed to investigate the association between fetal gender and GDM, and to assess whether fetal gender modifies the influence of maternal risk factors such as age and pre-pregnancy body mass index (BMI). Materials and Methods: This retrospective cohort study was conducted at the Third Department of Obstetrics and Gynecology, School of Medicine, Faculty of Health Sciences, Aristotle University of Thessaloniki, Greece between December 2023 and March 2025. Baseline characteristics were compared between groups. Multivariable logistic regression was used to assess independent associations with GDM, and interaction analysis was conducted to evaluate effect modification between fetal gender and maternal age or pre-pregnancy BMI. Results: The study included 926 pregnant women, of whom 138 (14.9%) were diagnosed with GDM. Maternal age and pre-pregnancy BMI were independently associated with GDM risk. No significant association was observed between fetal gender and GDM (adjusted OR = 1.05; 95% CI: 0.72–1.52; p = 0.79). Additionally, fetal gender did not significantly modify the effect of maternal age, BMI, or BMI categories on GDM risk in either additive or multiplicative interaction models (all p values >0.05). Conclusions: Fetal gender was not associated with GDM in this cohort and did not appear to modify the influence of maternal risk factors. These findings suggest that fetal gender may not play a significant role in GDM risk prediction, supporting the continued emphasis on maternal characteristics in risk assessment.