Effects of long bone on estimated fetal weight

Abstract

Objectives: An accurate estimation of fetal weight will help predict the macrosomic fetuses and determine the mode of delivery which reduce perinatal morbidity and mortality. In congenital abnormalities such as absence of femur and lower extremity agenesis, femur length can not be measured, or in patients with isolated femoral shortening, the calculation of estimated fetal weight can be misleading. So, in our study, we investigated the efficacy of the use of long bones in the calculation of estimated fetal weight in Turkish society. Material and Method: This retrospective study was conducted in Turgut Ozal University Hospital, Department of Obstetrics and Gynecology, among 400 healthy singleton pregnant women whose gestational ages were confirmed by the first trimester ultrasound and patients who had undergone a targeted ultrasonography in the 20th-22nd gestational weeks. Biparietal diameter, head circumference, abdominal circumference, femur length, humerus length, tibia length and ulna length were measured for each patient through detailed ultrasonography examinations. Results: In linear regression analysis for estimating fetal weight, bipariatal diameter, femur length, abdominal circumference, and tibia length were found to be more effective (pl0.001, pl0.001, pl0.001 and p=0.010, respectively). In the linear regression analysis including only the long bones, we have observed femur length, tibia length, and ulna length to be more effective (pl0.001, pl0.001 and p=0.014, respectively). Correlation analyses of long bones have revealed that all bones were highly correlated with each other (pl0.001 for each). Conclusion: In cases when FL, one of the most important parameters in TFA measurement, cannot be measured, tibia and ulna lenghts may be considered as alternatives. There is need for multicenter studies carried out with more patients to be able to develop different ideas on the matter. Key words: Estimated Fetal Weight; Femur Length; Long Bones.