Better Predictor of Fetal Weight: Mid-Thigh Soft- Tissue Thickness Versus Hadlock’s Method – A Prospective Observational Study

Abstract

Introduction: Estimation of fetal weight is necessary for planning and managing labor. At term, macrosomia can be predicted by the estimation of fetal soft tissue and can be done by various ultrasonographic measurements. The correlation of estimated fetal weight (EFW) using fetal soft-tissue thickness with actual birth weight was seen in this study. Materials and Methods: Seventy ladies with singleton pregnancies were enrolled. The fetal weight was categorized into two groups, above and below 90 th percentile respective of the gestational age. Fetal weight estimation was done using Hadlock's method, mid-thigh soft-tissue thickness (MTSTT) and was correlated with actual birth weight. Fetal abdominal subcutaneous tissue thickness (FASTT) was correlated with actual birth weight as well. Results: Moderate positive correlation was found between the EFW using MTSTT and Hadlock's method, and it was statistically significant (P < 0.001). FASTT had a mild positive correlation, which was not statistically significant. Further, MTSTT was found to be more sensitive and specific in the estimation of fetal weight with actual birth weight as a gold standard. Conclusions: Estimation of fetal weight using MTSTT was more superior to Hadlock's method with higher sensitivity and specificity values. There was no significant correlation observed between FASTT value and actual birth weight.