262 - Bronchopulmonary Dysplasia as Predictor of Long-Term Neurodevelopmental Outcome: A Population Based Cohort Study

Poster Number: 262
Publication Number: 262.225

Meghan Breckon, Dalhousie University Faculty of Medicine, Halifax, NS, Canada; Balpreet Singh, Dalhousie University Faculty of Medicine, Halifax, NS, Canada; Walid El-Naggar, Dalhousie University, Halifax, NS, Canada; Satvinder Ghotra, IWK Health Center, Halifax, NS, Canada

Background: Bronchopulmonary dysplasia (BPD) is a severe morbidity with a reported incidence of 62% among preterm infants born at < 29 weeks gestational age. There is inconsistency in studies reporting predictive accuracy of the current BPD definition for long-term neurodevelopmental and pulmonary outcomes.

Objective: The study's primary objective is to clarify the association between BPD, defined as oxygen requirement at 36 weeks postmenstrual age (PMA) and long-term neurodevelopmental outcomes.

Design/Methods: This retrospective population-based cohort study included all infants born at < 31 weeks gestational age between January 2002 and December 2017 in two Canadian provinces (Nova Scotia and Prince Edward Island). Infants with major congenital anomalies or who died before 36 weeks PMA were excluded. The primary outcome was moderate to severe neurodevelopmental impairment (NDI ) defined as Bayley Scales of Infant Development 2nd edition (BSID-II) cognitive or language score < 70 or level 2 to 5 on Gross Motor Functional Classification System, and/or presence of blindness or deafness at 18-36 months of corrected age. Univariate analysis and multivariate logistic regression models assessed risk factors for poor neurodevelopmental and pulmonary outcomes.

Results: There were 890 infants, including 231 infants with BPD (26%). Demographic characteristics are described in Table 1. In univariate analysis, moderate to severe NDI, cerebral palsy, BSID-II language and cognitive score < 70 and adverse pulmonary outcomes were significantly associated with BPD (Table 2). However, adjusting for covariates revealed a loss of significance for BPD and neurodevelopmental outcomes (OR=0.66 95%CI 0.33-1.34) (Table 2). Significant associations were observed for covariates grade III/IV interventricular hemorrhage (IVH) (OR=3.05, 95% CI 1.46-6.37), cystic periventricular leukomalacia (PVL) (OR=6.51, 95% CI 2.92-14.53), inotropic support (OR=2.22, 95% CI 1.06-4.64), and length of hospital stay (OR=1.01, 95% CI 1.01-1.02) (Table 3).Conclusion(s): In this population-based study with a low risk of selection bias, the currently used BPD definition is not associated with moderate-severe NDI in preterm infants < 31 weeks gestation. The strongest predictors of poor neurodevelopmental outcome were severe IVH, cystic PVL, inotropic support and length of hospital stay. These findings suggest that the current BPD definition lacks prognostic value and there is a need for better markers to assess disease severity and predict long-term outcomes.
Table 1 Demographic characteristics of BPD vs non-BPD GroupAbbreviations: BPD= bronchopulmonary dysplasia; SGA= small for gestational age; PDA= patent ductus arteriosus; PVL= periventricular leukomalacia; ROP= retinopathy of prematurity; SD= standard deviation.*p < 0.05.
Table 2 Unadjusted and adjusted odds ratios (OR) for primary and secondary outcomesOutcome definitions: Moderate to severe neurodevelopmental impairment (NDI): BSID-II cognitive or language score < 70, level 2 to 5 Gross Motor Functional Classification System (GMFCS), and/or presence of blindness or deafness. Moderate NDI: level 2 or 3 GMFCS, and/or, MDI score < 70. Severe NDI: severe disability (level 4 or 5 GMFCS, and/or MDI score < 55, and/or presence of blindness, and/ or, deafness. Cerebral palsy (CP) levels: GMFCS levels 1-5. Significant respiratory morbidity: Recurrent hospitilizations, wheezing episodes, use of inhaled steroids/bronchodilators, O2 use at home, tracheostomy or pulmonary hypertension.
Adjustors: Bronchopulmonary dysplasia (BPD), grade III-IV intraventricular hemorrhage, cystic periventricular leukomalacia, necrotizing enterocolitis, hemodynamically significant patent ductus arteriosus, duration of mechanical ventilation, gestational age, small for gestational age, culture positive sepsis, postnatal steroid use, and retinopathy of prematurity requiring intervention.*p < 0.05.