Incidência e fatores de risco da retinopatia da prematuridade no Hospital Universitário Onofre Lopes, Natal (RN) - Brasil

purposes: to determine the incidence of retinopathy of prematurity and assess the main risk factors involved in its development. methods: retrospective cohort study carried out from january 2004 to december 2006, at university hospital onofre lopes, natal (rn) - brazil. the sample was composed of 663 newborns, with less than or equal to 36 weeks of gestational age and/or birth weight less than or equal to 1,500 g, submitted to the protocol of retinopathy of prematurity in the ophthalmology department of the hospital. the variables were: gender, birth weight, gestational age, duration of oxygen therapy, mechanical ventilation, sepsis and blood transfusion. data were analyzed through the chi-squared test, fisher's exact test and logistic regression model. results: of the 663 cases, retinopathy of prematurity occurred in 414 (62.4%). of the total sample, 338 (51.0%) were male and 282 (42.5%) female. mean and standard deviation of weight, gestational age and duration of oxygen therapy were, respectively, 1,334.9 ± 345.6 g, 31.9 ± 2.3 weeks and 10.0 ± 14.0 days. the incidence of retinopathy in premature newborns in the period was 62.4%, 58.0% of cases in 2004, 67.2% in 2005 and 63.0% in 2006. the multiple logistic regression analysis showed that the weight less than 1,000 g (p<0.001; adjor=17.18, ci= 6.52-45.29) and between 1,000 g and 1,500 g (p=0.002; adjor -4.20 ci= 1.68-10.48), the time of oxygen lounger than 20 days (p=0.022; adjor=3.40, ci= 1.19-9.69) and blood transfusion (p=0.022; adjor -2.06, ci= 1.11-3.83) are independent factors for the disease. conclusions: the study showed a high incidence of the disease in the service. a low birth weight, a prolonged oxygen therapy and blood transfusion are factors associated with the development of retinopathy of prematurity. gestational age is not a reliable parameter for screening of newborns in the service.