Relationship between sonographic umbilical cord size and gestational age among pregnant women in Enugu, Nigeria.

BACKGROUND Common fetal parameters for gestational age (GA) estimation have pitfalls especially in advanced pregnancy and pregnancy complicated by fetal structural anomaly. OBJECTIVE To assess the relationship between umbilical cord size and gestational age of the fetus. SUBJECTS AND METHODS A sonographic cross sectional study involving 300 pregnant women with GA between 14 weeks to 40 weeks was done in Enugu, Nigeria. Gestational ages were first estimated by use of Naegele's formula for GA estimation based on the date of onset of each subject's last menstrual period. Fetal parameters such as biparietal diameter, femur length, head circumference and abdominal circumference were measured and also used to estimate GA. Umbilical cord diameters were measured and used to compute the umbilical cord cross-sectional area. RESULTS The mean umbilical cord diameter and cross-sectional area were 14.5mm ± 7.2mm and 201.6mm ± 139.5mm(2) respectively. Umbilical cord growth rate of 1.0mm/week was noted between the 14(th) and 35(th) week of pregnancy. There were significant correlations (p < 0.001) between umbilical cord size and other fetal parameters for GA estimation. CONCLUSION Umbilical cord size had strong linear relationship with common fetal GA estimation parameters and could be used to compliment these parameters for GA estimation.