Preeclampsia and risk of developing bronchopulmonary dysplasia in very preterm neonates

Objective: Bronchopulmonary dysplasia (BPD) is a severe common complication of preterm birth with considerable short and long-term consequences. As more evidence is emerging that dysregulation of angiogenesis is implicated in the pathogenesis of preeclampsia as well as in fetal lung development, we assessed if preeclampsia is associated with development of BPD in very preterm neonates. Study design: A retrospective cohort study of 308 infants born between 24(+0) and 31(+6) weeks of gestation in 2011 and 2012. We performed association analysis with univariable and multivariable logistic regression, adjusting for confounders. Models were additionally adjusted for intermediates, to show how an association can be disguised by over adjusting. Main outcome measure: BPD was diagnosed at 36(+0) weeks postmenstrual age and defined as the need for oxygen (FiO2 > 0.21) for at least 12 h per day, for more than 28 days before or at 36(+0) weeks postmenstrual age, and classified as mild, moderate or severe. Results: After applying our exclusion criteria, we report our primary outcome on 247 mother-neonate pairs. Fifty-nine neonates developed BPD (23.9%) which was moderate to severe in 27 of them (10.9%). Preeclampsia was associated with BPD, adjusted odds ratio, 95% confidence interval: 4.22 (1.63, 10.91). However, after adjusting for additional intermediates no statistical significance remained, adjusted odds ratio, 95% confidence interval: 1.87 (0.49, 7.24). Conclusion: This study shows that early-onset preeclampsia is associated with development of BPD in the very preterm neonate. Part of this association is mediated by fetal growth restriction and mode of delivery.