Sonographic measurement of the umbilical cord and fetal anthropometric parameters

Objective: To determine reference ranges for the diameter and the cross-sec tional area of the umbilical cord during pregnancy and to determine if umbi lical cord morphometry is related to fetal size. Methods: A prospective cro ss-sectional study was designed to assess the sonographic cross-sectional d iameter and area of the umbilical cord. The sonographic umbilical cord meas urements were obtained in a plane adjacent to the insertion of the cord int o the fetal abdomen. Nomograms for the umbilical cord diameter and area wer e computed. Fetal biometry included: biparietal diameter, abdominal circumf erence, and femur length. Polynomial regression analysis was conducted. Res ults: Five hundred and fifty seven patients were included into the study. T he regression equation for the umbilical cord diameter (y) according to ges tational age (x) was y = -10.0563 + 1.4265x + 0.0194x(2) and for the umbili cal cord area (y') was y' = 91.6-3.3x + 0.03x(2)-0.00007x(3). A significant relationship was found between umbilical cord measurements and fetal anthr opometric parameters. Conclusion: Reference ranges for umbilical card diame ter and area have been generated. The sonographic diameter and cross-sectio nal area of the umbilical cord increase as a function of gestational age an d both diameter and area correlate with fetal size. (C) 1999 Elsevier Scien ce Ireland Ltd. All rights reserved.