Analysis of prenatal and postnatal risk factors of retinopathy of prematurity in a tertiary care hospital in South India

Context: Recent advances in neonatology have influenced the incidence and severity of ROP in a dichotomous fashion. Aims: To determine the incidence of ROP and to analyse its risk factors. Settings and Design: Prospective clinical case series. Materials and Methods: 282 preterm infants with birthweight <1500g and/or gestational age <= 32 weeks and also those with gestational age > 32 weeks, with birthweight between 1500-2000 g, who were at risk for ROP were selected. Weight gain proportion was measured as weight at 6 weeks minus birthweight divided by birthweight. Statistical Analysis: Univariate and multivariate logistic regression. Results: Incidence of any ROP was 21.6% while severe ROP was 6.7%. Prenatal factors like multiple gestation (P = 0.510) and antenatal steroids (P = 0.104) were not significantly associated with ROP. On multivariate analysis, postnatal factors like weight at birth < 1250 g (P = 0.01) and gestational age between 31-32 weeks (P = 0.02) were independent risk factors for any ROP, while intraventricular hemorrhage (P = 0.03) was the only independent risk factor for severe ROP. Mean birthweight of infants with severe ROP was 1056 +/- 207 g (P = 0.004), which was significantly low. After logistic regression, the mean weight gain proportion at 6 weeks, of those neonates with severe ROP was 30%. Conclusions: Low birthweight and prematurity were the most important risk factors for developing any ROP, while intraventricular hemorrhage was the independent risk factor for developing severe ROP. The mean postnatal weight gain at 6 weeks was not statistically significant in neonates with severe ROP.