Accuracy of Clinical and Ultrasound Foetal Weight Estimation in Predicting the Actual Birth Weight at Term at Federal Medical Centre, Keffi, Nasarawa State.

Abstract

The study set out to determine the accuracy of clinical and ultrasound fetal weight estimation in predicting the actual birth weight of pregnant women at term at the FMC, Keffi, North central Nigeria. It was a cross-sectional study that enrolled consecutive pregnant women. A total of 360 pregnant women at term, who met the inclusion criteria were recruited using interviewer-administered questionnaire. The clinical estimate was done using the Dare’s formula, ultrasound fetal weight estimation was done using an ultrasound scan machine imputed with the Hadlock formula mode (BPD, HC, AC, and FL), while the actual birth weight was measured in the labour room using the infant weighing scale. Quantitative variables were summarized using mean and standard deviation while categorical variables were summarized using frequencies and percentages. Accuracy was determined using percentage error, absolute percentage error, and proportion of accurate estimates within 10% of actual birth weight.

Analysis showed that, the mean percentage error and mean absolute percentage error were -13.78 ±12.44; 14.89 ±12.54 and 4.38 ±11.42; 9.81 ± 7.29 for clinical and ultrasound foetal weight estimations respectively. The correct estimate, within 10% of actual birth weight were 41.5% and 55 % for clinical and ultrasound foetal weight estimations respectively. It was concluded that, ultrasound method of fetal weight estimation overestimates the actual birth weight with lower absolute percentage error while clinical method under estimates. The proportion of correct estimates, within 10% of ABW are 55% and 41.5% for Ultrasound and Clinical methods respectively. However, clinical weight estimation can be used in a low-resource settings.