Background: It has been well known that foetal size at birth influences the maternal and perinatal outcome. Birth of small for gestational age (SGA) is associated with high rates of admission to neonatal intensive unit (NICU) for problems such as hypoxia, respiratory distress, whereas birth of large for gestational age (LGA) may cause more obstetric trauma during vaginal births and both conditions lead to high rates of operative abdominal delivery. Recent investigations have shown that single estimation of Umbilical Cord Cross Sectional Area (UCCSA) can reasonably predict foetal weight ranges.

Objective: To correlate fetal UCCSAobtained at the time of third trimester scan with neonatal birth weight.

Design: Prospective observational study over a period of two years.

Setting: Department of Obstetrics and Gynaecology, Kasturba Medical College, Manipal, Karnataka, India

Population: Two hundred and fifty women from 34 weeks gestational age who have delivered within 2 weeks of UCCSA.

Methods: Women from 34 weeks’ gestation, who presented for sonographic examination and who delivered within 2 weeks of the examination, were included in the study. The UCCSA was measured in a free loop of the umbilical cord. Linear regression analysis was used to correlate umbilical cord cross sectional area with neonatal birth weight.

Results: It was observed that proportion of cases with a lean umbilical cord was significantly higher in the group of small for gestational age group (60.7%) compared with other group (4.5%). A large umbilical cord was found in 65.2% of macrosomic babies compared with 4.4% in nonmacrosomic infants. All these association were found to be statistically significant (p<0.005).

Conclusion: There is a positive correlation between UCCSA and birth weight. As UCCSA increases, there is an increase in mean birth weight. 

Keywords: Umbilical Cord Cross Sectional Area (UCCSA); Small for Gestational Age (SGA); Macrosomia; Neonatal Birth Weight.