To Örebro University

Aim: This study evaluated poor weight gain as a risk factor for infants who required treatment for retinopathy of prematurity (ROP), by comparing those born before and after the implementation of higher oxygen saturation (SpO₂ ) targets at the Queen Silvia Children's Hospital, Gothenburg, Sweden.

Methods: We compared infants born at less than 31 weeks, who were screened and, or, treated for ROP: 127 in 2011-2012 when SpO₂ targets were 88-92% and 142 in 2015-2016 when they were 91-95%. The subjects were reviewed for birth characteristics, weekly weight and ROP treatment. Data were analysed using the weight, insulin-like growth factor 1, neonatal, ROP (WINROP) prediction tool.

Results: The 2011-2012 infants who needed ROP treatment (12.6%) had significantly poorer postnatal weight gain than those who did not, but this was not seen in the treated (17.6%) and nontreated ROP groups in 2015-2016. WINROP sensitivity decreased from 87.5% in 2011-12 to 48% in 2015-2016.

Conclusion: After the SpO₂ target range was increased from 88-92% to 91-95%, postnatal weight gain was no longer a significant risk factor and WINROP lost its ability to predict ROP requiring treatment. Risk factors clearly change as neonatal care develops.