Trisomy 21 and Risk of Retinopathy of Prematurity.

BACKGROUND AND OBJECTIVES Trisomy 21 is known to decrease the risk of several (nonocular) angiogenic-mediated diseases. The objective of this study was to determine whether trisomy 21 can also be shown to be significantly protective against ocular angiogenic-mediated disorders such as retinopathy of prematurity (ROP). METHODS A retrospective analysis of deidentified data from the Pediatrix BabySteps Clinical Warehouse. This large repository of neonatal data is approved for use in research studies by the Western Institutional Review Board. The study population consisted of 99,080 infants with very low birth weights (BWs; BW <1500 g), born between 1996 and 2013, cared for at >300 US NICUs, and who had been discharged alive from hospital. Statistical significance for unadjusted comparisons between groups was determined with Pearson's χ(2) test or Student's t test. Logistic regression models were used to calculate the odds of ROP (of any stage) and advanced ROP (stage 3 or greater) for infants with trisomy 21 compared with all other infants. RESULTS The prevalence of trisomy 21 was 0.3% in the study population (321 of 99,080). After adjustment for BW, gestational age, oxygen exposure, and other potential confounders, there was an odds ratio of 0.6 (95% confidence interval: 0.5-0.8) for ROP in infants with trisomy 21compared with other infants and an odds ratio of 0.4 (95% confidence interval: 0.1-0.9) for advanced-stage ROP. CONCLUSIONS Trisomy 21 significantly decreases the odds for ROP in very low BW infant survivors. This study unmasks a potentially identifiable genetic component to ROP risk, paving the way for the development of a laboratory-based ROP screening tool.