Potential Role of Bilirubin in Preventing Retinopathy of Prematurity

Abstract

Background: One of the most common problems in preterm neonates is retinopathy of prematurity (ROP). It has been shown antioxidants may be effective in preventing the development and progression of ROP. Considering the antioxidant properties of bilirubin, we decided to investigate the bilirubin level in neonates with ROP and compare it with healthy neonates.

Methods: This case-control study was performed on VLBW neonates admitted to the NICU of Ghaem Hospital in Mashhad between 2014 and 2020 for a Jaundice evaluation. Complete neonate's characteristics, maternal history and laboratory results were collected in a questionnaire. Then the neonates were examined for ROP by a fellowship of the retina of an ophthalmologist at 32 weeks or four weeks after birth. The highest bilirubin levels during their hospitalization were also recorded.

Results: Of 427 neonates examined, 121 (37.7%) had a normal eye examination, and 266 (62.3%) had ROP. The mean weight, gestational age and bilirubin were 1455.8 ± 431.4 grams, 31.6 ± 2.3 weeks and 8.8 ± 2.4 mg/dl, respectively. There was a significant difference between controls and neonates with ROP with regard to birth weight, duration of intermittent positive pressure ventilation (IPPV), duration of oxygen therapy, first and fifth minute Apgar scores, the maximum level of bilirubin and gestational age (P < 0.05). It was observed that the maximum level of bilirubin was lower in neonates with higher stages of ROP.

Conclusion: According to the results of this study, higher levels of bilirubin in neonates may be a protective factor against ROP. Moreover, increased levels of bilirubin are associated with reduced severity of ROP. Therefore, prophylaxis phototherapy in premature infants may need to be reconsidered.

Keywords: Premature infant; antioxidant; hyperbilirubinemia; intraventricular hemorrhage (IVH); necrotizing enterocolitis (NEC); periventricular leukomalacia (PVL); retinopathy of prematurity (ROP).