Over the years, several fetal growth standards were proposed, based on either fetal or neonatal data, and they include 1) one-size-fits-all; 2) customized by race/ethnic group and other maternal and fetal characteristics; and 3) fetus specific (individualized). Achieving consensus about which standard is more suitable for clinical use requires evaluation of the predictive performance of available fetal growth standards with respect to clinically relevant outcomes. However, such comparisons are hindered by lack of a simple software tool that implements most of the growth standards in use.
To address this need, PRB investigators developed a spreadsheet-based estimated fetal weight percentile calculator and corresponding R software package (for batch calculation) to encompass six fetal growth standards. The collection of software tools is called Fetal Growth Percentile Software (FetalGPS). The six fetal growth standards implemented in FetalGPS are: 1) INTERGROWTH-21st; 2) World Health Organization (WHO); 3) NICHD; 4) Perinatology Research Branch (PRB/NICHD); 5) Hadlock; and 6) Fetal Medicine Foundation (FMF). The software generates exact percentiles for all the growth standards implemented, which makes possible the assessment of fetal growth based on custom percentile cut-off values as previously reported.