Correlation of Cross-sectional Area of the Umbilical Cord on Antenatal Ultrasound with Neonatal Birth Weight in Pregnant Women with and without Gestational Diabetes Mellitus: A Prospective Cohort Study

Introduction: Many foetal and maternal complications, such as polyhydramnios, macrosomia, birth injuries, and operative interference, are linked with Gestational Diabetes Mellitus (GDM). Among these, macrosomia is particularly significant, as it increases the risk of shoulder dystocia, brachial plexus injury, birth asphyxia, and maternal complications, including emergency Lower Segment Caesarean Section (LSCS), Postpartum Haemorrhage (PPH), and perineal trauma. Therefore, one of the most essential perinatal goals in GDM is to predict macrosomia by estimating birth weight, thereby preventing adverse maternal and foetal outcomes. Aim: To evaluate whether there is a correlation between the cross-sectional area of the Umbilical Cord (UCA) and the Neonatal Birth Weight (NBW) in pregnant women with GDM. Materials and Methods: A prospective cohort study was conducted in the Departments of Radiology and Obstetrics Bangalore Medical College, Bengaluru, Karnataka, India. A total of 100 pregnant women (50 with GDM and 50 without GDM) were recruited from July 2021 to July 2022. Ultrasound examination (USG) was performed on pregnant women after 36 weeks of gestation. The UCA was measured in a free-floating loop, and the NBW was measured using a digital scale. The correlation coefficient was calculated to determine the degree of correlation between UCA and NBW. Results: The mean age of the subjects was 26.5±3.9 years. The frequency of macrosomia was higher in the GDM group (8%) compared to the control group (4%). A strong positive correlation was observed between UCA and NBW in both diabetics (r=0.819) and control groups (r=0.736). Conclusion: A strong positive correlation exists between UCA and NBW in women with GDM. Therefore, it should be estimated during routine antenatal USG for the prediction of birth weight in such women.