133 THE ASSOCIATION OF POSTNATAL GROWTH VELOCITY WITH RETINOPATHY OF PREMATURITY AND BRONCHOPULMONARY DYSPLASIA IN PERTERM INFANTS: A POPULATION BASED RETROSPECTIVE COHORT STUDY

Abstract

Retinopathy of prematurity (ROP) and bronchopulmonary dysplasia (BPD) are associated with multiple risk factors, but the etiologies and pathophysiology of these conditions are not completely understood. Recent evidence suggests that poor postnatal weight gain may contribute to the development of both ROP and BPD. This study aimed to investigate if in preterm infants, poor growth velocity, defined as weight gain velocity (WGV) <15 g/kg/day, in the first 4 weeks of life is a risk factor for ROP and BPD. A total of 725 preterm infants with gestational age < 30 weeks born between 2003 and 2015 were retrospectively reviewed. The primary outcomes assessed were development of ROP ≥ stage 3 and development of BPD, defined as need for supplemental oxygen for ≥28 days and a need for ≥30% oxygen/nasal CPAP/ mechanical ventilation at 36 weeks PMA/discharge. WGV was calculated using exponential model of estimating growth velocity as follows: WGV = (1000 x ln (Wn/W1))/(Dn − D1); wherein, W1 is birth weight (BW), Wn is weight at discharge/desired time point, D1 is 0 and Dn is day at discharge/desired time point. Of the 725 infants, 670 were categorized as having poor WGV. In the poor WGV cohort, the incidence of ROP was significantly higher than in the good WGV cohort (adjusted odds ratio, 3.257; 95% confidence interval, 1.999–10.638, P= 0.039). Similarly, in the poor WGV cohort, the incidence of BPD was significantly higher than in the good WGV cohort (adjusted odds ratio, 3.497; 95% confidence interval, 1.464–9.524; P= 0.003). After performing multivariable logistic regression controlling for maternal age, maternal diabetes, pregnancy-induced hypertension, clinical chorioamnionitis, antenatal corticosteroid, cesarean section, sex, gestational age, BW, Apgar score (AS) (1 and 5 min), respiratory distress syndrome (RDS) requiring surfactant, patent ductus arteriosus (PDA), necrotizing enterocolitis (NEC), severe intraventricular hemorrhage (IVH) (grade III-IV), blood culture positive sepsis, WGV was found to be an independent risk factor for both ROP and BPD (P= 0.000 and P= 0.002 respectively). Similarly, after performing multivariable logistic regression using WGV as a continuous variable, WGV was found to be an independent risk factor for ROP and BPD (P= 0.002 and P= 0.015). Poor weight gain velocity in the first 4 weeks of life is an important and independent risk factor for ROP and BPD.