Antenatal ultrasound measurement of fetal-thigh soft-tissue thickness as a predictor of fetal birth weight

Abstract

Objectives To assess the use of antenatal estimation of fetal-thigh soft-tissue thickness as a predictor for the actual neonatal birth weight (ABW) after delivery. Background Fetal weight estimation has become increasingly important, especially for evaluation of fetopelvic disproportion, decision for mode of delivery in complications of pregnancy, and in detection of intrauterine growth restriction. Patients and methods A prospective study was conducted on 72 pregnant women with different gravidity and parity attending the delivery room at Obstetrics and Gynecology Department, Menoufia University Hospital during April 2019 till June 2020. An antenatal ultrasound examination within 48 h of their delivery was done. The delivered neonates were weighted immediately after delivery to estimate the ABW. Results Of the 72 women included and who delivered within 48 h (ABW range, 2500–4200), their mean age was 26.34 ± 5.49 years, and gestational age was in the range from 37 to 41 years, with a mean of 38.7 ± 0.92 weeks. There were highly statistically significant differences between estimated fetal weight and ABW of the studied cases (P = 0.001). The prediction of fetal weight was similar between the formulas, although estimate of the new algorithm was more accurate, showing positive predictive value of 94% compared with 91% for Hadlock's. Conclusion The study concluded that the estimation of fetal antenatal estimated birth weight using new algorithm of estimated fetal-thigh soft-tissue thickness is more accurate and specific for estimation the expected ABW than using the standard Hadlock's formula.