Ultrasonography of Normal Fetal Kidney Width Measurement for Estimation of Gestational Age in Sudanese Pregnant Women

Abstract

Background: A precise estimate of gestational age (GA) is essential for providing optimal maternity care and determining the labor date. Aim: This study aimed to determine gestational age between the 14th and 40th weeks for Sudanese pregnant women by measuring the normal fetal kidney width using ultrasound. Methods: The study was designed as a descriptive cross-sectional study in Khartoum and Gezira states, Sudan, from June 2016 to May 2017. Three hundred ninety healthy pregnant women aged between 15 and 45 years were assessed by ultrasound, with overall normal well-being fetuses. Linear regression models for estimating gestational age were developed based on biometric markers and kidney width. Stepwise regression models were created to determine the most effective model for measuring gestational age that occur between 14 and 40 weeks. Comparisons were subsequently made between the models' effectiveness in identifying gestational age. Results: The most accurate variable parameter assessed in this study was kidney width, with a standard error (SE) of 0.02 days, followed by kidney length (SE = 0.04 days), biparietal diameter (BPD) (SE = 0.10 days), and femur length (FL) (SE = 0.13 days). The abdominal circumference was the least accurate, with an SE of 1.35 days. There was a strong association between GA and kidney width (R = 0.72, P < 0.002). Conclusions: The kidney width (KW) is easy to identify and measure. It is the most accurate parameter for estimating GA compared to other biometric indices in the late second and third trimesters and could be easily incorporated into models for estimating GA.