Maternal Adiposity in the First Trimester Pregnancy as a Predictor of Gestational Diabetes Mellitus: A Prospective Cohort Study.

Objectives: To evaluate the predictive ability of first-trimester ultrasound measurements of maternal adiposity for predicting gestational diabetes mellitus (GDM).

Methods: Abdominal adiposity measurements by transabdominal ultrasound were performed, including subcutaneous fat thickness (SFT), visceral fat thickness (VFT), and preperitoneal fat thickness (PFT), measured at 3 specific regions: the umbilicus, suprapubic area, and anterior surface of the liver. Two additional values were calculated based on these measurements: total abdominal fat thickness (TAT), which was determined as the sum of SFT1 and VFT, and body fat index (BFI), which was calculated using the formula: BFI = PFT (mm) × SFT3 (mm)/maternal height (cm). Multiple logistic regression and receiver operating characteristic (ROC) analysis were used to evaluate the predictive ability.

Results: A total of 330 pregnant women were enrolled with a prevalence of GDM of 23.0%. Multivariate logistic regression analysis showed that none of the fat parameters were significantly associated with GDM. However, for body mass index (BMI) ≥25 kg/m², only the BFI showed a statistically significant association with GDM (odds ratio [OR] 2.75 [1.54-4.92]), with an area under the ROC curve (AUC) of 0.677. In the subgroup with BMI < 23 kg/m², only SFT at the umbilicus was significantly associated with GDM (OR 3.21 [1.08-9.53]) using a cut-off value of ≥15.4 mm, with a sensitivity of 73.7%, a negative predictive value of 93.8%, and an AUC of 0.668.

Conclusions: Both BFI and SFT at the umbilical region demonstrate moderate discriminatory predictive performance for this condition across BMI-stratified subgroups.