Abstract 136

Many preterm and small for gestational age (SGA) neonates are unable to mount a ketogenic response to hypoglycaemia thus reducing the availability of alternative fuels for the brain1. Our aim was to asses neonatal metabolic adaptation in relation to breastfeeding in these vulnerable babies.

53 healthy babies up to 4 postnatal days were studied, 33 were preterm(34-36 weeks), median birthweight (bwt) 2320g (range 1820-3180g) and 20 were term SGA babies (bwt≤2nd %ile), median bwt 2488g (range 2020-2760g). 14 were exclusively breastfed (BF), 31 received formula supplements (FS) and 8 were exclusively formula fed (FF). Prefeed blood glucose and ketone body concentrations were measured. Feeding regimen and glucose monitoring were according to current UK guidelines2.

For all preterm and SGA babies, mean blood glucose levels did not differ significantly among the 3 groups (BF-2.79 mmol/l, FS-3.01 mmol/l, FF-2.91 mmol/l). However, median ketone body concentration (KB) was significantly higher in the BF group (0.915 mmol/l) compared to the FS group (0.543 mmol/l) and compared to the FF group (0.146 mmol/l)(p=0.0001). This difference in KB persisted when the preterm and SGA groups were analysed separately. Furthermore, there was a significant negative correlation between KB and volume of formula taken (mls/kg/day) (rs=-0.52, p<0.001). These data suggest that breastmilk augments neonatal metabolic adaptation in small babies and may have a direct ketogenic effect. The findings demonstrate the clinical benefits of breastfeeding especially in small babies.