Identification of clinical factors associated with timing and duration of spontaneous regression of retinopathy of prematurity not requiring treatment

Objective: Identify clinical factors that delay or prolong spontaneous regression of retinopathy of prematurity (ROP). Study design: Secondary analysis of three prospective studies with 76 infants with ROP not requiring treatment, born ≤30 weeks postmenstrual age (PMA) and ≤1500 grams. Outcomes were PMA at greatest severity of ROP (PMA MSROP), at which regression began, at time of complete vascularization (PMA CV), and regression duration. Pearson’s correlation coefficients, t-tests, or analyses of variance were calculated. Results: Increased positive bacterial cultures, hyperglycemia, transfusion volume of platelets and red blood cells and severity of ROP were associated with later PMA MSROP. Positive bacterial cultures, maternal chorioamnionitis, and less iron deficiency were associated with later PMA CV and prolonged regression duration. Slower length gain was associated with later PMA CV. P < 0.05 for all. Conclusions: Preterm infants with inflammatory exposures or linear growth impairment may require longer surveillance for ROP resolution and complete vascularization.