Predicting proliferative retinopathy in a Brazilian population of preterm infants with the screening algorithm WINROP

Abstract

Objective: To retrospectively validate the WINROP (weight, insulinlike growth factor I, neonatal, retinopathy of prematurity [ROP]) algorithm in a Brazilian population. WINROP aims to predict ROP and is based on longitudinal weight measurements from birth until postmenstrual age 36 weeks. WINROP has predicted 100% of severe ROP in 3 neonatal intensive care unit settings in the United States and Sweden.

Methods: In children admitted to the neonatal intensive care unit at Hospital de Clínicas de Porto Alegre, Porto Alegre, Brazil, from April 2002 to October 2008, weight measurements had been recorded once a week for children screened for ROP, 366 of whom had a gestational age of 32 weeks or less. The participating children had a median gestational age of 30 weeks (range, 24-32 weeks) at birth and their median birth weight was 1215 g (range, 505-2000 g).

Results: For 192 of 366 children (53%), no alarm or low-risk alarm after postmenstrual age 32 weeks occurred. Of these, 190 of 192 did not develop proliferative disease. Two boys with severe sepsis who were treated for ROP received low-risk alarms at postmenstrual age 33 and 34 weeks, respectively. The remaining 174 children (47%) received high- or low-risk alarms before or at 32 weeks. Of these infants, 21 (12%) developed proliferative ROP.

Conclusions: In this Brazilian population, WINROP, with limited information on specific gestational age and date of weight measurement, detected early 90.5% of infants who developed stage 3 ROP and correctly predicted the majority who did not. Adjustments to the algorithm for specific neonatal intensive care unit populations may improve the results for specific preterm populations.