Estimating fetal age: computer-assisted analysis of multiple fetal growth parameters.

TLDR

The study examines the advantages and potential pitfalls of a computer‑assisted fetal dating system. Regression models using real‑time sonographic measurements of biparietal diameter, head circumference, abdominal circumference, and femur length were developed in a cross‑sectional study of 361 fetuses to predict menstrual age. Head circumference and femur length were the strongest individual predictors, and combinations of parameters—especially head circumference with femur length—yielded significantly better age estimates than single parameters, while simple averaging produced comparable results.

Abstract

Regression models for predicting menstrual age based on real-time sonographic measurements of four fetal parameters (biparietal diameter, head circumference, abdominal circumference, and femur length), used alone and in combination, were developed in a cross-sectional study of 361 fetuses between 14 and 42 menstrual weeks. The head circumference and femur length were the strongest individual predictors of age. A number of combinations of fetal parameters, including the combination of head circumference and femur length, provided age estimates that were significantly better (p = 0.05) than those using any single parameter alone. It was also demonstrated that simply averaging individual age estimates in a given case could provide results that were not significantly different from those obtained by using the same parameters in a complex regression equation. The advantages and potential pitfalls of this system of fetal dating are discussed.