Neonatal anthropometric measurements to predict birth weight by ultrasound

Abstract

Objective: To develop a more accurate ultrasound birth weight (BW) model using neonatal anthropometric measurements. Study Design: Two hundred thirty-one newborns were evaluated. Measurements included weight; head, chest, and abdominal circumferences (umbilicus and liver), humerus, and femur lengths. Infants were randomly assigned into two groups (G1 and G2). Anthropometric measurements that are obtainable by ultrasound were generated from G1. Stepwise regression and a bootstrap analysis were used to create the prediction models. The models were validated using G2. Results: The final stepwise regression model included FL and circumferences of the head, chest, and abdomen. The correlations were: G1: R2=0.91, p<0.001; G2: R2=0.90 p < 0.001. There was no difference between derived and actual BW in G1 (p=0.42) or G2 (p=0.28). The mean absolute percent error between the prediction model and actual BW was 3.8%. Conclusion: Neonatal anthropometric models are strongly predictive of actual BW. This model will be tested prospectively using ultrasound to predict fetal weight.