Estimation of Gestational Age in Third Trimester by Fetal Kidney Length Using Ultrasonography

Abstract

Estimation of gestational age plays an important role in maternity care. Ultrasound provides an accurate method of determining fetal age in utero. There was some limitation in routine ultrasound parameter that use in estimation of gestational age such as biparital diameter and femur length that lead to under or over estimation of gestational. The aim of this study were to measure the fetal right renal length and to determine if renal length can be used correctly to estimated gestational age and to compare it with other ultrasound parameters that was used routinely in estimation of gestational age, including biparital diameter and femur length. Across sectional study was done at ELmek Nimir university hospital from August to December 2018, by using ultrasound machine (Fukuda Denshi) curved linear transducer 3.5MHZ, for 50 healthy pregnant women, all were sure of their last menstrual period and with single live fetus and no maternal or fetal complications. Their ages were between (15-40) years. The study was done during the 27-40 week of gestation by measuring biparital diameter and femur length, the gestational age was measured and right renal length in millimeters. The results were analyzed and showed there was strong positive correlation between RT kidney length in mm with gestation age in weeks (R2= 0.95), which is significant at p-value 0.01.and the length of RT kidney increase by 0.96 each week from 25 weeks of gestation. The study obtained that kidney length was accurate parameter for estimating gestational age than other biometric indices in third trimester and could be easily incorporated into the models for estimating gestational age.