Comparison of New AIIMS Versus Fenton Growth Charts for Classification of Small-for-gestational-age (SGA) Neonates: A Retrospective Study

Introduction The classification of neonates based on weight at birth as small-for-gestational-age (SGA), using available growth charts, has a significant bearing on their immediate postnatal care and long-term management. Aims and Objectives To compare the performance of New AIIMS versus Fenton growth charts in identifying SGA neonates and their risk of short-term adverse outcomes. Materials and Methods A retrospective medical record review was conducted among inborn neonates at a tertiary care hospital from January 2019 to December 2021. Birth weight, sex, and gestational age along with maternal details and significant postnatal events (including NICU admission) were recorded. Birthweights were plotted against gestational age on both the New AIIMS and Fenton charts under comparison. Short-term adverse outcomes among all enrolled SGA neonates were collected till the time of discharge. Sensitivity and specificity for diagnosing the risk of short-term adverse outcomes as compared to AGA neonates were calculated. Results Among the 1,924 enrolled neonates, 16.5% and 30.3% neonates were classified as SGA as per the New AIIMS and Fenton Growth charts respectively. A total of 35.8% of SGA neonates, as per Fenton charts had short-term adverse outcomes in comparison to 37.5% as per the New AIIMS charts. The odds ratio for predicting short-term adverse outcomes among SGA neonates on Fenton and New AIIMS charts were 1.61 and 2.32, respectively. Conclusions Compared to the New AIIMS growth charts, Fenton growth charts carry the risk of over diagnosing SGA neonates and their risk of short-term adverse events.