Impact of Bronchopulmonary Dysplasia, Brain Injury, and Severe Retinopathy on the Outcome of Extremely Low-Birth-Weight Infants at 18 Months: Results From the Trial of Indomethacin Prophylaxis in Preterms

Abstract

Research on outcomes in extremely low-birth-weight (ELBW) infants has to date failed to demonstrate to what degree neonatal disorders predict long-term outcomes. This cohort study, enrolling 910 infants weighing 500 to 999 g at birth, attempted to learn the prognostic influence of bronchopulmonary dysplasia (BPD), ultrasound signs of brain injury, and severe retinopathy of prematurity (ROP) separately and together. The infants were admitted to 32 neonatal intensive-care units in Canada, the United States, Australia, New Zealand, and Hong Kong from 1996 through 1998. All of them lived to a postmenstrual age of 36 weeks and were followed up prospectively for 18 months. BPD developed in 45% of the cohort, ultrasonographic signs of brain injury in 21%, and severe ROP in 10%. Each of these conditions, but particularly severe ROP, was strongly associated with a poor outcome at 18 months of age. BPD was somewhat less predictive of the long-term outcome than the other morbidities. All 3 conditions appeared to have independent prognostic value, and the odds ratios associated with each of them were of similar magnitude. The risk of a poor long-term outcome (death, cerebral palsy, cognitive delay, severe hearing loss, bilateral blindness) in infants lacking all 3 neonatal morbidities was 18%. The figure was 42% when any one of these morbidities was present, 62% with 2 of them, and 88% when all 3 were present. Nearly the same predictive accuracy was achieved using a model based on a simple morbidity count. This remained the case when considering birth weight, gestational age, race (white or nonwhite), and maternal educational level. This study showed that, in ELBW infants who live to 36 weeks' postmenstrual age, a simple count of 3 common neonatal morbid conditions greatly improves the prediction of death or survival with neurosensory impairment by age 18 months. This should be very helpful in counseling parents and foreseeing specific needs.