Significance of neonatal body indices in identifying fetal macrosomia

To explore the significance of neonatal body indices in identifying macrosomic infants, we compared the neonatal birth weight, body length, head circumference, chest circumference, neonatal body indices, Quetelet index (QI), Kaup Index (KI), head circumference to chest circumference ratio (HC/CC) and maternal fasting blood glucose (BG) for both diabetic and healthy mothers.

This is a retrospective study of 177 macrosomic neonates, 100 having been born to normal mothers and 77 to diabetic mothers. Multiple regression analyses were done between neonatal body indices and maternal fasting BG.

Fetal QI and KI indices of macrosomic infants of diabetic mothers were higher compared with those born to healthy mothers, whereas the HC/CC was the reverse. The multiple regression equation used to compare neonatal physical development indices to maternal fasting BG was BG=6.959+0.031QI-(4.482 × HC/CC). QI and HC/CC had linear relationships to maternal fasting BG (P<0.05). As birth weight had no direct correlation with maternal fasting BG, it was not introduced into the regression equation.

Higher QI and KI along with lower HC/CC may be a predictor of macrosomia due to maternal diabetes when compared with birth weight alone.