Prevalence and risk factors for retinopathy of prematurity: study with 450 very low birth weight preterm infants

Purpose: This study aims to analyze prevalence and risk factors for retinopathy of prematurity (ROP) among preterms with birth weight (BW) d" 1,500 grams and/or gestational age (GA) d" 32 weeks, admitted in an University level 3 institution. Methods: An institutional, prospective and descriptive cohort study including all preterms with BW d" 1,500 grams and/or GA d" 32 weeks, who survived from birth to the 42(nd) week of postmentrual age, was carried out from October 2002 to July 2008. The prevalence of any stage ROP and the main risk factors of postnatal period for ROP were compared by uni and multivariate analysis. Continuous variables were analysed by Student's t-Test. Chi-square was used to compare cathegoric variables. To the logistic regression were included all of the significant variables after univariate analysis. Results: Retinopathy in any evolutive stage has affected 24.2% of the babies. Threshold disease needing treatment has appeared in 24 patients (5.3%). After univariate analysis, GA, BW, use of mechanical ventilation and indomethacin, occurrence of intraventricular hemorrhage and sepsis, and need of blood transfusions, have been associated with ROP. Logistic regression has confirmed the great importance of GA (OR: 0,856; IC95%: 1,141-1,447; P= 0,014), low weight gain from birth to the 6(th) week of life (OR: 0,997; IC95%: 0,996-0,999; P< 0,001), use of mechanical ventilation (OR: 1,770; IC95%: 1,0293,046; P= 0,039), and need of blood transfusions (OR: 1,285; IC95%: 1,141-1,447; P< 0,001), as independent risk factors for developing of ROP among preterms with BW d" 1,500 grams. Conclusion: This study has shown prevalence of ROP and need of treatment among this institution's preterms comparable to other international studies. The main risk factors for ROP in this cohort were related with the BW, the postnatal low weight gain, and therapies like mechanical ventilation and blood transfusions.