Incidence and main risk factors for severe retinopathy of prematurity in infants weighing less than 1000 grams in Brazil.

OBJECTIVES This study evaluated the incidence and risk factors for severe retinopathy of prematurity (ROP) in babies <1000 g at Porto Alegre, Brazil. METHODS Prospective cohort study including premature children with birth weight ≤1000 g was conducted. Main outcome was the occurrence of severe ROP needing treatment. RESULTS A total of 157 infants were included. Severe ROP occurred in 20 infants (12.7%). Nineteen patients were treated by laser photocoagulation. Main risk factors for severe ROP were gestational age (P = 0.029), infant's weight measured at sixth week of life (P < 0.001) and number of days of oxygen therapy under mechanical ventilation (P < 0.001). After logistic regression, infant's weight at sixth week of life and number of days in mechanical ventilation were associated to severe ROP. CONCLUSIONS We reported the incidence of 12.7% of severe ROP among babies born ≤ 1000 g in our institution. Laser photocoagulation was effective to stabilize the disease among 19 treated patients.