RESUMO
OBJECTIVE: To determine the normal cross-sectional areas of the umbilical vein, umbilical artery, and Wharton jelly in healthy pregnancies, and correlate the obtained values with fetal anthropometric parameters. METHODS: A cross-sectional study was performed with 312 women between the 24th and 39th weeks of a normal pregnancy. The cross-sectional areas of umbilical cord vessels were measured at the junction of the cord and fetal abdomen, and the values were subtracted from the total cord cross-sectional area to assess the cross-sectional area of the Wharton jelly. The anthropometric parameters analyzed were biparietal diameter, head circumference, femur length, and estimated fetal weight, and the Spearman correlation was used to assess the correlation between the cross-sectional areas of umbilical cord components and fetal anthropometric parameters. A polynomial regression analysis was performed to identify the curves that best adjusted to mean and standard deviation according to gestational age. RESULTS: A statistically significant correlation was observed between the cross-sectional areas of cord components and fetal anthropometric parameters (P<0.001) as well as gestational age (P<0.001). CONCLUSIONS: Reference measurements of the cross-sectional areas of umbilical cord components are important tools in the assessment of fetal growth.