Sonographic evaluation of the impact of umbilical cord insertion site on fetal weight

Background: Abnormal insertion of the umbilical cord (UC) into the placenta may initiate fetal growth restriction and potentially complicates labor with intrapartum hemorrhage. The aim of this study was to sonographically determine the relationship between umbilical cord insertion types and estimated fetal weight (EFW). Methods: This prospective cross-sectional study was done in a 7-month period and recruited 220 pregnant women with 27 to 37 weeks gestation attending the antenatal clinic of the Hospital. Ultrasound scan was done on the women to determine UC insertion and EFW. Data was analyzed using SPSS 23.0. Results: Peripheral UC had significantly higher EFW, age and BMI (P=0.000), (P=0.009) and (P=0.003). The difference in EFW between peripheral UC and central UC in BMI ≥ 30 kg/m2 was significant within the 31st – 32nd week of gestation (P=0.001) and 33rd – 34th week of gestation (P=0.034). EFW was least in velamentous UC subtype (1.385±0.12 kg) compared to central UC type (1.95±0.65 kg), eccentric UC subtype (2.29±0.77 kg) and marginal UC subtype (2.47±0.83 kg). Peripheral UC was significantly associated with BMI (P=0.000), employment status (P=0.048), past history of CS (P=0.000) and placental location (P=0.001). Conclusion: Fetal weight, in the third trimester, is greater in obese pregnant women with peripheral umbilical cord insertion, except with velamentous cord insertion, and this is significant between 31st and 34th weeks of gestation. Peripheral umbilical cord insertion is significantly associated with high maternal BMI, posterior placental location, past history of cesarean section and being employed.