Estimation of Fetal Age sonographically using Umbilical Cord diameter in second and third trimester

Abstract

Ultrasound has been used for assessment of the gestational age of the fetus for years. Umbilical cord diameter is not used in assessing the gestational age routinely. The main objective of this study was to determine the gestational age by ultrasound measuring the umbilical cord diameter in the second and third trimester of pregnancy, as well as to compare between GA by UCD, FL and BPD. A total of 50 pregnant ladies from police hospital and Elazhary center were enrolled to U/S measurement of BPD, FL and two diameters of UC, using (SIEMENS-SONOLINE G60S) machine, those measurements were compare with the GA that taken by LMP, also maternal age and number of parity are included during a period of two months has been taken into account from December 2011 to February 2012 . In the manual assessment of gestational age, from one to three days were omitted and from four to six days were considered a week. UCD was measured in millimeters. The gestational ages by certain last menstrual period was compared to that obtained from measuring. It was found that the gestational age using umbilical cord diameter1 (depth), the equation show strong correlation where GA increase by 1.4/5mm, when used UCD2 (width) the equation showed GA increase by 1.5/5mm. The result showed that there was unsubstantial relation between UCD and maternal age, where the UCD increased by 0.02mm/10year and with an insignificant correlation at p = 0.05 with r = 0.03. Also there was a direct linear effect of the parity on the UCD1 increased by 0.55 mm/2parity and the UCD2 by 0.5 mm/2parity with a significant correlation at p = 0.05 with a correlation coefficient equal to 0,78 and 0.71 respectively. Using paired t-test it indicates that the GAs calculated from FL were accurate i.e. there is no significant difference at p = 0.05 detect between the LMP age and the estimated with t = 0.63 and p = 0.53 as well as the UCD1, UCD2 with t = 0.02 for both and p = 0.9 but BPD showed significant difference at p = 0.005 with t =2.92. So these equations can be using to estimate the fetal age.