Longitudinal postnatal weight measurements for the prediction of retinopathy of prematurity

Objective To validate longitudinal postnatal weight gain as a method for predicting severe retinopathy of prematurity (ROP) in a US cohort. Methods Both ROP evaluations and weekly weight measurements from birth to postmenstrual week 36 for 318 infants were entered into a computer-based surveillance system, WINROP. This system signaled an alarm when the rate of weight gain decreased compared with control subjects. Infants were classified into 3 groups: (1) no alarm, (2) low-risk alarm, or (3) high-risk alarm. Maximum ROP for each infant was categorized as (1) no ROP (immature or mature vascularization), (2) mild ROP (stage 1 or 2 ROP in zone II or III, without plus disease), or (3) severe ROP (any prethreshold, any stage 3, or threshold ROP). A high-risk alarm identified infants at risk for developing severe ROP. Results A high-risk alarm occurred in 81 infants (25.5%) and detected all infants who developed severe ROP a median of 9 weeks before diagnosis. The remaining infants received no alarm or a low-risk alarm. None of these infants developed more than mild ROP. Conclusions Longitudinal postnatal weight gain may help predict ROP. In a US cohort, the WINROP system had a sensitivity of 100% and identified infants early who developed severe ROP. With further validation, WINROP has the potential to safely reduce the number of ROP examinations.