Fetal biometry at 30 weeks as a predictor of large for gestational age new born

Abstract

Introduction: fetal ultrasound has achieved a central role in the modern diagnosis of fetal growth deviations.

Objective: to determine the local discriminatory power and performance of fetal biometric variables at 30 weeks on the trophic condition of a newborn large for gestational age.

Methods: an observational, analytical and retrospective study was carried out in three health areas of the Santa Clara municipality, in the period between January 2013 and December 2019. From a population of 5,733 births, 1,896 were selected by simple random sampling. Data from records of genetic consultations were obtained; Areas under the Receiver Operating Characteristic curve were constructed and performance indicators for diagnostic tests were calculated.

Results: the areas under the curve of the biometric variables discriminate those born large for gestational age, which allows the estimation of local cut-off points. The biometrics performance indicators maintain a regular behavior; those calculated by transforming the values ​​from the reference tables are more specific; and those calculated by transforming the variables by the estimated cut-off points raise the sensitivity.

Conclusions: all biometric variables have discriminatory capacity for large-for-gestational-age births. The performance indicators of the fetal biometric variables show superiority according to the estimated cut-off points with respect to those of the reference tables.