Objective: Infants who meet the screening guidelines for retinopathy of prematurity (ROP) based on birth weight and gestational age undergo serial ophthalmological examinations for its detection and treatment. However, <10% of patients require treatment, and less than half develop ROP. Poor postnatal weight gain has been reported to be a strong indicator of ROP development; however, the information regarding this is unclear. Therefore, this study aimed to determine the relationship between postnatal weight gain and ROP development in preterm infants.
Methods: The data of 675 preterm infants with gestational age ≤32 weeks, who were hospitalized in our neonatal intensive care unit, were obtained retrospectively from file records. The infants' demographic characteristics, clinical findings, and weekly weight gain (g/kg/day) during the first 8 weeks were recorded. The univariate was used to examine the risk factors for ROP followed by multivariate regression.
Results: The incidence of ROP in the infants included in the study was 41% (n = 278) and 13.3% (n = 37) of them required treatment. In the infants of the group that developed ROP, the mean birth weight and gestational age were significantly lower than those in the group that did not develop ROP (973 ± 288 and 1301 ± 349 g, p = 0.001 and 28.48 ± 1.95 and 30.08 ± 1.60 weeks, p = 0.001, respectively). As the gestational week and birth weight decreased, ROP development and the risk of ROP-requiring treatment increased. In the infants of the group that developed ROP, the mean weight gain in the postnatal third week was detected as significantly lower compared to those in the group that did not develop ROP (13.9 ± 8.2 and 15.4 ± 6.8 g, p = 0.034). On multiple logistic regression analysis, birth weight (<750 g) (odds ratio [OR], 8.67; 95% confidence interval [CI], 3.99-18.82, p = 0.001), blood transfusion (OR, 2.39; 95% CI, 1.34-4.24, p = 0.003), necrotizing enterocolitis (OR, 4.79; 95% CI, 1.05-26.85, p = 0.045), bronchopulmonary dysplasia (OR, 2.03; 95% CI, 1.22-3.36, p = 0.006), antenatal steroid therapy (OR, 1.60; 95% CI, 1.05-2.43, p = 0.028), surfactant administration (OR, 2.06; 95% CI, 1.32-3.2, p = 0.001) were independent risk factors for ROP development.
Conclusion: Postnatal weight gain may not be an accurate predictor of ROP development after adjusting for confounding factors. However, the analysis of independent risk factors that influenced the development of ROP revealed a statistically significant effect in cases of low birth weight, blood transfusion, necrotizing enterocolitis, bronchopulmonary dysplasia, and antenatal steroid and surfactant therapies. These findings may help ophthalmologists and neonatologists to pay special attention to this patient group during ROP scanning.
Keywords: Low birth weight; postnatal weight gain; preterm infant; retinopathy of prematurity; risk factors.