Risk of Retinopathy of Prematurity in Preterm Births with Respiratory Distress Syndrome: A Population-Based Cohort Study in Taiwan

Background: Respiratory distress syndrome (RDS) is a risk factor that plays an important role in retinopathy in preterm infants. We used population data of infants to investigate this relationship. This study evaluated whether respiratory distress syndrome was associated with an increased incidence of ROP in preterm infants. Methods: From the National Health Insurance claims data of Taiwan in the 2000-2009 period, preterm infants were identified to establish a RDS cohort (N = 7573) and a comparison cohort without RDS (N = 11428). We followed each infant for one year to identify incident retinopathy of prematurity (ROP) for comparison between the two cohorts. The RDS cohort for comparisons of hazard ratio (HR) with 95% confidence interval (CI) were calculated. Results: Low birth weight, an extended stay in the neonatal intensive care unit (NICU), female gender, and RDS were factors associated with an increased incidence of ROP. The ROP incidence was 2.5-fold higher in RDS children than in control (30.3 versus 11.9 per 100 person-years), with an adjusted HR (aHR) of 1.28 (95% CI = 1.18-1.39). The incidence increased as the birth weight decreased in both cohorts, but the RDS cohort to the comparison cohort aHR decreased as the birth weight decreased, not significant for groups with birth weights less than 1500g. The aHR for RDS children was the highest for infants with a normal birth weight: 3.33 (95% CI = 2.09-5.31). Among infants with RDS, the ROP incidence increased to 51.0 per 100 person-years in those who underwent invasive ventilation, or to 76.3 per 100 person-years for NICU stay for >= 30 days. Conclusion: Preterm infants with RDS are at an elevated risk of developing ROP, not limited to those with low birth weights.