Impact of gestational diabetes and obesity on maternal blood pressure trajectory and neonatal anthropometry

Introduction Maternal obesity is common among women with gestational diabetes mellitus (GDM) and is recognized as a risk factor for hypertensive disorders in pregnancy and adverse neonatal outcomes. This study aimed to assess the influence of maternal overweight and obesity on blood pressure progression during pregnancy, including mean arterial pressure (MAP), and on neonatal anthropometric outcomes in women with controlled gestational diabetes mellitus (GDM). Methods This retrospective observational cohort study included 102 pregnant women with controlled gestational diabetes mellitus who were followed at a tertiary referral center between 2016 and 2023 . We stratified participants with GDM by pregestational body mass index (BMI) into two groups: GDM with normal weight (BMI < 25 kg/m 2 ) and GDM with overweight/obesity (BMI ≥ 25 kg/m 2 ). We assessed maternal systolic blood pressure (SBP), diastolic blood pressure (DBP), and MAP throughout pregnancy according to hypertensive status. Neonatal outcomes included birth weight, length, head circumference, chest circumference, abdominal circumference, ponderal index, and gestational age classification. Statistical analyses comprised ANOVA, generalized linear models, repeated-measures analysis, and Tukey's post hoc test, with statistical significance set at p < 0.05. Results Normotensive women with GDM and overweight/obesity exhibited numerically higher second-trimester MAP than women without GDM and overweight/obesity (87.5 vs. 82.37 mmHg); however, this difference was not statistically significant after adjustment for multiple comparisons ( p = 0.095). Longitudinal analysis demonstrated attenuation of the physiological mid-pregnancy decline in MAP among participants with GDM with overweight/obesity. Birth weight was significantly higher among newborns of mothers with GDM with overweight/obesity, particularly in the gestational hypertension subgroup, in which the mean birth weight exceeded 4000.00 g (4058.75 vs. 3035.00 g; p < 0.0001). We observed no significant differences in neonatal body proportionality or gestational age classification. Discussion Maternal overweight and obesity in women with controlled gestational diabetes mellitus were associated with altered maternal hemodynamic adaptation and increased neonatal birth weight despite adequate glycemic and blood pressure control. These findings support the concept of combined GDM and overweight/obesity as a distinct metabolic-vascular condition associated with persistent alterations in maternal vascular adaptation and fetal growth. Earlier integrated prenatal strategies targeting maternal metabolic, cardiovascular, and nutritional health may improve maternal and neonatal outcomes.