Relationship between Sonographic Umbilical cord Diameter and Gestational Age in Third Trimester of Pregnancy

Background: Throughout the fourth week of embryonic development the umbilical cord (UC) is formed, which corresponds to the fifth to the twelfth weeks of gestation. Fetuses with intrauterine growth restriction (IUGR) have leaner UCs than fetuses of appropriate gestational age do, and the caliber of the umbilical vein decreases significantly, resulting in a worsening of the Doppler parameters of the umbilical artery in the mother. The goal of this study was to evaluate the significance of sonographic UC diameter in determining gestational age in third trimester in pregnant women.

Methods: We conducted a comparative cross-sectional research on 300 pregnant women aged range between (20-35) years, singleton gestation, gestational age (3rd) trimester estimated from antenatal mothers last menstrual period (LMP), viable fetus, presenting to obstetrics and gynecology department at Tanta university hospital.

Results: Highly statistically significant positive correlation between UC diameter and gestational age, BPD, FL, AC, AFI, and estimated fetal weight was found. The increase in UC diameter was positively and significantly correlated with the increase in gestational age and estimated fetal weight, indicating that those who have prolonged gestational age and estimated fetal weight are more likely to have wider UC diameter.

Conclusions: The UC diameter (UCD) has the potential to be a valuable indicator of fetal growth, well-being, and perinatal outcome.

Sonographic measurement of UC diameter could be an efficient method of measuring fetal growth and predicting gestational age (GA), particularly between 28-40 weeks GA. It is possible that abnormal UC diameter can be a strong indicator to identify antenatal mothers at risk for IUFD and poor fetal outcomes.