Sonographic Correlation of Umbilical Venous Flow Rate and Fetal Abdominal Subcutaneous Tissue Thickness With Estimated Fetal Weight

Objective: To determine the correlation of umbilical venous flow rate (UV-Q) and fetal abdominal subcutaneous tissue thickness (FASTT) with estimated fetal weight (EFW), and explore the possibility of utilizing UV-Q and FASTT to predict EFW. Materials and Methods: A total of 110 singleton pregnancies between 27 and 37 weeks were enrolled into this study. UV-Q and FASTT were measured at the sonographic imaging plane where the abdominal circumference is measured. Estimated gestational age (EGA) and EFW were determined according to the standard sonographic measurement protocol. Results: UV-Q and FASTT ranged between 29.10 and 387.01 mL/min, and between 0.40 and 1.10 cm, respectively, and both correlated positively with EGA and EFW ( p = .000). Mean UV-Q and mean FASTT increased in a linear fashion from 27 to 37 weeks of gestation. An EFW prediction equation was established using UV-Q and FASTT; EFW = 0.561 + 0.005 (UV-Q) + 1.165 (FASTT). Conclusion: The proposed equation derived from measuring UV-Q, at the intra-abdominal site, and FASTT, may be a diagnostic tool that could be adopted for the determination of EFW, in the third trimester. Further studies are needed to replicate this work and assess the potential clinical application of the equation for fetal monitoring during pregnancy.