Analysis of risk factors for progression to treatment-requiring ROP in a single neonatal intensive care unit: is the exposure time relevant?

OBJECTIVE: Retinopathy of prematurity (ROP) is a multifactorial disease whose pathogenesis is organized in two phases. We hypothesized that postnatal risk factors may differently exert their effect in a phase dependent way.
METHODS: Data obtained from medical records of 93 very low birth weight neonates with stage ≥ 3 ROP were analyzed. Perinatal ROP risk factors were compared between infants with stage 3 ROP not requiring surgery and infants with treatment-requiring ROP with relation to newborn's lifetime exposure.
RESULTS: In the first two weeks and in the whole first month of life length of oxygen administration was an independent risk factor for treatment-requiring ROP. In the first month of life also sepsis was identified as independent risk factor for surgical ROP. Sepsis and Candida pneumonia in the time frame from birth to ROP diagnosis and prolonged mechanical ventilation from diagnosis to prethreshold ROP were associated to treatment-requiring ROP. Blood transfusions are the only risk factor for treatment-requiring ROP identified in all the periods analyzed.
CONCLUSION: Risk factors for ROP play their role since birth. Beside scrupulous oxygen-administration monitoring and prevention of infections, blood transfusions are of primary importance in the development of treatment-requiring ROP.