Predictive Value of Fat-Related Body Composition in Early Pregnancy for Macrosomia Using Propensity Score Matching

This prospective cohort study aimed to assess the predictive capacity of fat-related body composition in early pregnancy for macrosomia and facilitate early screening.

We analyzed 949 women who delivered at Suzhou Hospital Affiliated to Nanjing Medical University (Suzhou Municipal Hospital) between March 2021 and March 2022, categorized into 54 macrosomia, 869 normal-weight, and 26 low-weight deliveries. At 13 weeks gestation, maternal adiposity indices, including fat mass index (FMI) and percent body fat, were measured. Propensity score matching (PSM) was performed at a 1:2 ratio to compare 53 macrosomic mothers with 106 normal mothers, controlling for maternal height, gestational age, and neonatal sex. Multivariate logistic regression identified independent risk factors for macrosomia.

The macrosomia group exhibited significantly higher prepregnancy BMI (22.44 vs. 20.95 kg/m2), body fat percentage (32.41% vs. 29.58%), and FMI (7.16 vs. 6.09 kg/m2, all p < 0.001) than the control group. Notably, FMI (OR = 1.428, 95% CI: 1.017, 2.003, p = 0.039) and gestational age (OR = 1.619, 95% CI: 1.095, 2.395, p = 0.016) emerged as independent risk factors for macrosomia. The diagnostic accuracy of FMI for predicting macrosomia was moderate, with an area under the curve of 73.2%.

FMI during early pregnancy can serve as a predictive marker for macrosomia. Due to the objectivity and simplicity, FMI can be incorporated into prenatal care, which enables targeted lifestyle interventions, such as dietary counseling and exercise, reducing adverse pregnancy outcomes.