Evaluating the Role of Ultrasonographic Measurements in Assessing Macrosomia Among the Fetuses of High-Risk Antenatal Women in a Tertiary Care Hospital

Background and objective Fetal macrosomia, defined as a birth weight >4.0 kg, is associated with serious maternal and neonatal complications such as prolonged labor, cesarean delivery, postpartum hemorrhage, birth trauma, and long-term metabolic risks. Maternal factors, particularly gestational diabetes mellitus (GDM), excessive weight gain, and certain comorbidities, increase the risk of macrosomia. Early detection in high-risk pregnancies is crucial to guide clinical management and improve outcomes. Conventional sonographic estimated fetal weight (EFW) provides important information but may lack accuracy. Novel markers such as umbilical cord thickness (UCT), fetal fat layer (FFL), and shoulder pad thickness (SPT) have shown potential predictive value. This study aimed to evaluate the accuracy of these sonographic parameters in predicting fetal macrosomia among high-risk pregnancies in a tertiary care setting. Methodology This prospective hospital-based study was conducted at Sree Balaji Medical College and Hospital, Chennai, from July 2023 to June 2024. A total of 100 high-risk antenatal women at 35-36 weeks of gestation were recruited through purposive sampling. Inclusion criteria were pregnancies complicated by GDM, anemia, hypertensive disorders, bronchial asthma, epilepsy, or cardiac conditions. Women with multiple pregnancies, fetal anomalies, or unwillingness to participate were excluded. After informed consent, detailed histories and anthropometric data were recorded, followed by ultrasonographic measurements of UCT, FFL, SPT, and EFW. Outcomes were followed up till delivery. Results Out of the total 100 participants, the majority of women were aged 31-35 years (44%) and primigravida (59%). High-risk conditions included GDM (65%), anemia (16%), and hypertensive disorders (9%). Macrosomia occurred in 49% cases, predominantly among overweight women (37/49, 75.5%), upper socioeconomic class (45/49, 92.3%), and GDM mothers (49/65, 75.4%) (all p<0.001). Male infants were more affected (28/49, 57.1%, p=0.034). UCT >90th percentile, FFL >5 mm, and SPT >12 mm were exclusively associated with macrosomia (all p<0.001). EFW >4.0 kg predicted macrosomia with 100% accuracy. Macrosomia was most frequent in <i>LSCS</i> deliveries (19/20, 95%). Conclusion Umbilical cord thickness, fetal fat layer, and shoulder pad thickness are reliable predictors of fetal macrosomia in high-risk pregnancies. GDM emerged as the strongest maternal risk factor. Incorporating these sonographic markers into routine third-trimester screening may improve early detection, optimize delivery planning, and reduce maternal and neonatal complications.