The aim of this prospective multicentre study was to evaluate the influence of a number of perinatal factors on the development of ROP in high risk preterm infants with gestational age < or =30 weeks. All infants consecutively born in, or transferred to, one of the 14 participating centres from 1 January 1992 through 31 December 1993, who had a gestational age of 30 weeks or less and no congenital anomalies and survived to the age of 6 months, were included in the study. Of the 380 infants with mean +/- SD gestational age of 28.4 +/- 1.6 weeks (range 23-30 weeks) and birth weight of 1157 +/- 335 g (range 485-2480 g) that were eligible for the study, 82 (21.5%) developed ROP stage 1 or 2 and 57 (15%) ROP stage 3 or 3+. Step-wise logistic regression analysis showed that the following factors had a significant predictive value for the development of ROP stage 3 or 3+: gestational age (Odds Ratio (OR) = 0.6144 for each increment of 1 week of gestational age), birth weight (OR = 0.843 for each increment of 100 g of birth weight), prenatal steroids (OR 4.044 for lacking or incomplete prophylaxis), RDS (OR 2.294), oxygen dependency at 60 days (OR 2.085), necrotising enterocolitis (OR 2.597).
Conclusion: This study confirms the role of prematurity, low birth weight and RDS in the pathogenesis of ROP, and emphasises the importance of prenatal steroid prophylaxis of RDS in very preterm infants. Furthermore, our data suggest that infants with oxygen dependency at 60 days or necrotising enterocolitis are at very high risk of developing ROP.