Estimation of Fetal Weight by Clinical Methods and Ultrasonography and Comparing with Actual Birth Weight

Introduction: Assessment of fetal weight is a vital factor in antenatal care, not only in the management of labor and delivery but also in identifying fetal weight disorders. Objective: This study compares the accuracy of clinical methods and ultrasonography in Estimating Fetal Weight (EFW) with Actual Birth Weight (ABW) in term pregnant women. Materials and Methods: This diagnostic test evaluation study was performed on ۲۴۷ single-term pregnant women admitted to an educational, therapeutic hospital in Rasht City, Iran. In this study, abdominal palpation, Johnson’s formula, Insler’s formula, and ultrasonography were used to estimate fetal weight. One-sample t-test, the Chi-square, and the Bland-Altman plot were used to compare the diagnostic value of fetal weight estimation methods. The accuracy of tests was estimated based on sensitivity and specificity in fetal weight groups (below ۲۵۰۰ g, ۲۵۰۰- ۴۰۰۰ g, and above ۴۰۰۰ g) by the Bland-Altman plot.Results: The participating pregnant women had a Mean±SD age of ۲۸.۸۶±۴.۲۴ years, body mass index of ۳۲.۹۸±۶.۰ kg/m۲, and gestational age of ۳۹±۱.۰۴ wk. Their Mean±SD actual birth weight was ۳۳۴۳.۳۵۲±۴۳۲.۷۹۹ gr, Also, the Mean±SD birth weight found by abdominal palpation was ۳۳۷۱.۰۵۳±۳۴۵.۵۶۱ gr, Mean±SD birth weight by Johnson’s formula ۳۰۴۱.۲۰۶±۴۱۱gr, by Insler’s formula ۳۵۵۶.۳۱۶±۵۳۱.۵۶۷ gr, and by ultrasonography ۳۲۹۴.۲۸±۳۸۰.۰۹gr, Based on the one-sample t-test, the abdominal palpation had the lowest (P=۰.۲۶۱), and the Insler’s formula (P=۰.۰۰۱) had the highest difference with the actual birth weight. Regarding the fetal weight groups, Insler’s formula (۹۶.۳۳%) was highly accurate in Low Birth Weight (LBW), but abdominal palpation (۹۱.۰۹%) was more accurate in normal weight and macrosomia (۹۴.۷۲%) groups. There was a significant difference۲between clinical methods with ABW (P=۰.۰۲۶). Conclusion: Clinical methods are accessible, affordable, and available and can estimate fetal weight in developing countries, especially in our country.

کلیدواژه ها:

Fetal weight ، Birth weight ، Ultrasonography ، Pregnancy ، Estimation techniques