Higher incidence of retinopathy of prematurity in extremely preterm infants associated with improved survival rates

Aim: This study assessed possible reasons for the increasing incidence of retinopathy of prematurity (ROP) since mid-2015 at our institution.

Methods: Retrospective analysis of all preterm infants born July 2013 to June 2017 with a gestational age (GA) <29 completed weeks admitted to the neonatal intensive care unit at the University Hospital Zurich during the first 28 days of life. The primary outcome measures were severest ROP stage. Statistical analysis was performed using generalised additive models in R.

Results: During the study period, survival increased in extremely preterm infants. Significant predictors for severest ROP stage were GA, days of mechanical ventilation and multiple gestation (P = .0322). A composite of severe comorbidities had no significant effect on severest ROP stage. GA was identified as the only significant risk factor the for severest ROP stage (P = .0045).

Conclusion: Increased survival rate of extremely preterm infants was associated with an increased incidence of ROP at our institution. Despite the increase, the incidence is still very low compared with other countries. No other additive factors were identified.