Background: Previous studies suggest that reducing target oxygen saturation levels to 85-93% decreases the incidence of severe retinopathy of prematurity (ROP). Our aim was to determine if a more modest reduction in target oxygen saturation levels also reduces ROP incidence.
Methods: One neonatal intensive care unit instituted new oxygen saturation guidelines that changed target levels from the upper 90s to 90-96%. We conducted a retrospective cohort study to determine the proportion of eyes that progressed to (1) threshold or type-1 ROP and (2) stage 3. These proportions were compared between two groups of all eligible infants born up to 10 months before (higher oxygen group, n = 46) and up to 16 months after (lower oxygen group, n = 59) the policy change. Binomial regression was used to calculate relative risks adjusted for birth weight, gestational age, apnea, days of mechanical ventilation, and length of hospital stay.
Results: Sixteen of 90 eyes (18%) in the higher oxygen group developed threshold or type-1 ROP versus 16 of 118 eyes (14%) in the lower oxygen group (adjusted relative risk = 0.66, 95% CI = 0.29, 1.51). Twenty-two of 88 eyes (25%) in the higher oxygen group developed stage 3 ROP versus 26 of 118 eyes (22%) in the lower oxygen group (adjusted relative risk = 0.76, 95% CI = 0.43, 1.37).
Conclusions: We observed a small but statistically insignificant reduction in the incidence of severe ROP after a modest reduction in target oxygen saturation levels to 90 to 96% in the first several weeks of life.