Time to Regain Birth Weight - A Marker to Predict the Severity of Retinopathy of Prematurity?

Abstract Background: Poor weight gain in the first few weeks of life has been studied as a predictor of retinopathy of prematurity (ROP). Our aim was to assess whether time taken to regain birthweight be used as an additional marker to identify infants needing treatment for ROP.Methods: In this retrospective study, preterm infants (<27 weeks gestational age at birth) born during the period from 1/1/2010-31/12/2015 at a level 3 neonatal intensive care unit in Australia were included. 27 cases (ROP needing treatment) were identified. Controls (ROP not needing treatment or no ROP) were matched with cases on gestational age at birth and birthweight (1:4 ratio). Data were collected from the database and medical records.Results: The median (IQR) gestational age for cases and controls were 24 (24-26) and 25 (24-26) weeks respectively and median (IQR) birthweight for cases and controls were 675 (635-810) and 773 (666-884) grams respectively. Cases were more likely to be intra uterine growth restricted (18.5% vs 3.7%, p=0.015) and had increased weeks on oxygen (median 11.9 vs 9.1, p=0.028). Median (IQR) time to regain birth weight in cases and controls were 9 (6-13) and 7 (5-10) days respectively. Time to regain birthweight approached statistical significance when adjusted for duration of oxygen (aOR 1.08, 95% CI 1.00-1.17, p=0.054). The area under the curve from the time to regain BW ROC analysis with adjustment for IUGR and duration of oxygen was 0.73 (95% CI 0.62-0.83).Conclusion: Time to regain BW has potential to aid prediction of ROP needing treatment.