Adjusted poor weight gain for birth weight and gestational age as a predictor of severe ROP in VLBW infants.

Aim: To analyze relative weight gain by 2-week intervals up to 6 weeks after birth in order to predict the development of retinopathy of prematurity (ROP) requiring treatment among very low birth weight (BW) infants.

Methods: A prospective study including infants with BW ≤1500 g born in a single tertiary intensive care unit over 1-year period was conducted. Body weight measurements were recorded weekly and relative weight gains (g/kg/day) were calculated. The main outcome was development of ROP requiring treatment.

Results: Mean BW and gestational age (GA) of the whole cohort were 1165±223 g and 29.3±2.3 weeks, respectively. Relative weight gain at 2 weeks and 4 weeks postnatal age were significantly lower in infants with severe ROP (P=0.041 and P=0.017, respectively). Relative weight gain at 6 weeks was not different between groups. Infants with severe ROP gained 6.7±4 g/kg/day in the first 4 weeks of life, compared with 9.3±4.5 g/kg/day for those with mild or no ROP. After adjusted for BW and GA in logistic regression poor relative weight gain in the first 4 weeks was found to be related to severe ROP (P=0.015). When all the other risk factors significant for severe ROP were included in the logistic regression poor weight gain did not arise as an independent risk factor.

Conclusion: Poor postnatal weight gain in the first 4 weeks of life is the end result of several comorbidities rather than being an independent risk factor. Poor weight gain can be an additional predictor of severe ROP in very low BW infants.