Comparison of regional versus global growth charts for the classification of small-for-gestational age neonates

Objective To compare the performance of regional versus global charts for identifying small-for-gestational age (SGA) neonates with short-term adverse outcomes. Design Prospective cohort study. Setting Level-3 neonatal unit in India. Patients Neonates were categorised into SGA and appropriate-for-gestational age (AGA; 10th-90th centile) using four charts, namely, the AIIMS, Lubchenco, Fenton and Intergrowth 21st charts. They were followed up for adverse outcomes until 28 days. Outcomes We evaluated the (1) burden of SGA, (2) sensitivity and diagnostic OR (DOR), (3) relative risk (RR) and number needed to screen (NNS) to detect adverse outcomes in SGA versus 'optimal' AGA (50th-90th centile) and (4) RR of morbidities in 'additional SGA' (ie, classified as SGA by others but not by AIIMS chart). Results Among 1367 neonates, 19.6%, 4.5% and 12.5% were classified as SGA by Intergrowth 21st, AIIMS and Lubchenco charts, respectively. Intergrowth 21st had the highest sensitivity (39.1%) but the least DOR (2.6) to detect adverse outcomes; AIIMS chart had low sensitivity (19.3%) but higher DOR (4.3). RR and NNS were 3.7 and 14; 4.4 and 7; 4.0 and 8; 3.6 and 10 with Intergrowth 21st, AIIMS, Lubchenco and Fenton charts, respectively. 'Additional SGA' identified by Intergrowth 21st had lower risk of adverse outcomes than SGA identified by both the charts (RR 0.39; 95% CI 0.19 to 0.82). Conclusions Compared with AIIMS and Lubchenco charts, Intergrowth 21st runs the risk of overdiagnosing SGA neonates who may not be at a higher risk of short-term morbidities. This prospective study from India explores the short terms outcomes (up to 28 days) in small for gestation age babies as identified by regional vs global growth charts.

Automated summary

This prospective study from India compares the performance of regional and global charts in identifying small-for-gestational age (SGA) neonates with short-term adverse outcomes. The findings suggest that, compared to AIIMS and Lubchenco charts, the Intergrowth 21st chart may result in overdiagnosis of SGA neonates who may not be at a higher risk of short-term morbidities.