A New Sonographic Weight Estimation Formula for Small-for-Gestational-Age Fetuses

Area of Science:

• Perinatal medicine
• Fetal development
• Biostatistics

Background:

• Accurate fetal weight estimation is crucial for managing small-for-gestational-age (SGA) infants.
• Existing formulas may lack specificity for asymmetric versus symmetric growth patterns in SGA fetuses.

Purpose of the Study:

• To develop and validate a novel, specific formula for estimating fetal weight in SGA fetuses.
• To differentiate weight estimation accuracy based on symmetric and asymmetric fetal growth patterns.

Main Methods:

• Component-wise gradient boosting statistical technique applied to 898 SGA fetuses.
• Data from 750 symmetric and 148 asymmetric SGA fetuses used for formula derivation.
• Comparison of the new formula against established weight estimation equations.

Main Results:

• A new formula incorporating biparietal diameter, head circumference, abdominal circumference, femur length, sex, gestational age, and SGA asymmetry was derived.
• The new formula demonstrated the lowest median absolute percentage error, mean percentage error, and random error.
• Superior distribution of absolute percentage errors within defined bounds was observed for the new formula.

Conclusions:

• The newly developed formula significantly enhances the accuracy of fetal weight estimation in SGA cases.
• The formula's ability to account for growth patterns improves clinical management of SGA fetuses.