Cognitive skills in preterm infants with bronchopulmonary dysplasia at 1 year adjusted and 2 years chronological age

Abstract

Objective: The objective of this study was to evaluate for decline in cognitive scores from 12 to 24 months of age for preterm infants ≤32 weeks gestational age for those with and without bronchopulmonary dysplasia.

Study design: In an observational retrospective study, detailed medical data was collected from the electronic medical records of preterm infants born between January 2009 and December 2015 who had cognitive evaluations using Bayley Scales of Infant Development, 3rd ed (BISD-3) at 12 months corrected gestational age and 24 months chronological age. Infants were divided into three groups, bronchopulmonary dysplasia (BPD), prolonged oxygen requirement that did not meet BPD criteria, or pulmonary insufficiency (PI), and respiratory distress only (RDS). Decline in cognitive functions was based on the BISD-3 standard deviation of 15 points, no decline ≤3.5 point, moderate, > 3.5 to <7.5 points, significant >7.5 points.

Results: The sample included 165 preterm infants divided into three groups, BPD, n = 39, PI, n = 79, RDS only, n = 47. The groups did not differ on gender, ethnicity, birthweight or gestational age. The groups did not differ in percent of infants who showed no, moderate or significant decline. In all groups, the percentage of infants showing a cognitive decline of >7.5 points varied from 67% to 76%

Conclusion: There was no significant difference in cognitive decline for those with and without BPD. Of note is that a large percentage of infants in each group showed at least one-half standard deviation of cognitive decline across the 12 and 24 months evaluations. Our concern is that correcting for gestational age at 12 months may delay early intervention when significant delays are found at 24 months.

Keywords:

• Adjusted age
• Bayley Scales of Infant Development 3rd ed
• bronchopulmonary dysplasia
• cognitive scores
• prematurity

Disclosure statement

No potential conflict of interest was reported by the authors.