Comparative study between clinical and sonographic estimation of fetal weight in third trimester of pregnancy and its relationship with actual birth weight.

This prospective study was undertaken to assess the accuracy of clinical and sonographic estimated fetal weight (EFW) in Bangladeshi population. The study protocol consisted of achieving clinical followed by sonographic estimated fetal weight (uEFW) using Shepard formula and then its correlation with actual birth weight (BW). A total of 140 pregnant women participated in this study. The study was conducted in the department of Radiology & Imaging and in the department of Gynae & Obs., Bangladesh Medical College Hospital (BMCH) from January 2005 to December 2005.Maximum number of patients belonged to 26-30 years age group and the mean +/-SD age of the study patients was 26.8+/-4.7 years. Maximum number of women (41.4%) was primigravida and 24.3% women were second gravida. The mean+/-SD gestational age of the patient was 35.9+/-2.8 weeks. We found, clinically EFW was 3432.1+/-410.1 gm (mean+/-SD) and uEFW was 2715.4+/-509.1gm (mean+/-SD) with difference 716.7+/-278.5 gm (mean+/-SD), (P<0.001), which is highly significant. Babies who were delivered within 1st week of clinical and sonographic EFW were selected and their weights were compared with actual BW. The Pearson correlation chi square test and student 't' test were the statistical analysis used. It was found that the P value of clinical versus actual BW was <0.05, this was significant. P value of sonographic versus actual BW was >0.05, this was not significant. Percent error (PE) was found 2+/-7.33% in calculating uEFW from actual BW with minimum error -23.9% and maximum error 11.81%. This study conducted on Bangladeshi fetus using the Shepard formula showed that the actual BW recorded after delivery of the fetus is more close to uEFW than clinically EFW.