Fetal Thigh Circumference for the Prediction of Fetal Birth Weight using Ultrasound

Background: Accurate foetal birth weight estimate is crucial for detecting growth limitation, preterm, and situations where clinical decisions affecting labour induction or delivery mode need to be made.This research study was conducted to determine the accuracy of predicting prenatal weight using foetal thigh circumference (TC).
Patients and methods: Between November 2018 and September 2019, we performed a cross-sectional study of pregnant women. We included single intrauterine pregnant women with no complications, and who delivered within 48 hours after examination, with gestational ages ranging from 38 to 41 weeks. Within 48 hours following birth, the true foetal weight was estimated.
Results: We included 123 pregnant women, with a mean gestational age of 38.78 (SD 0.85) weeks and a mean age of 26.68 (SD 5.24) years. Of them, 21.1% were nulliparous. We found an ultrasound parameter-to-actual-weight association that was statistically significant in favour. The greatest association between actual foetal weight and TC (r =0.685; p < 0.001). Simple linear regression showed that TC is a predictor of estimated fetal weight (B =153.5, p < 0.001). Between estimated foetal weight and actual weight, as well as between estimated and real TC, we found no discernible difference (p values 0.398 and 0.06, respectively).
Conclusion: When used in conjunction with other fetal measures, the foetal thigh circumference may aid in the precise computation of fetal birth weight. To increase the accuracy of birth estimations, regular ultrasound examinations should include fetal thigh circumference measurement.