Analysis of the risk factors of persistent pulmonary hypertension in neonates

Abstract

Objective To investigate the high risk factors of persistent pulmonary hypertension (PPHN) in preterm and full-term neonates. Methods Fifty-six newborns with PPHN were divided into preterm neonates group and the full-term neonates group according to their gestational ages.The relationship between PPHN and high risk factors such as the primary diseases, mother′s complications during pregnancy, and the prognosis were analyzed retrospectively in each group.A retrospective review of lung samples of 3 neonates who died of respiratory failure were carried out. Results Thirty-one (55.36%) out of 56 neonates with PPHN including 27 preterm and 29 full-term newborns had parenchyma diseases.The first and the second primary diseases were meconium aspiration syndrome (MAS, 9/29 cases, 31.03%) and congenital heart diseases (8/29 cases, 27.59%) in the full-term group, and respiratory distress syndrome (RDS, 16/27 cases, 59.26%) and infection (8/27 cases, 29.63%) in preterm group, respectively.There were 15 cases (55.56%) whose mothers had complications during pregnancy among the 27 preterm neonates, and 8 cases (27.59%) among the 29 full-term neonates.The morbidity of mothers′ complications during pregnancy in preterm neonates was higher than that in full-term neonates (χ2=4.519, P=0.034). The mortality rate was 33.33% (9/27 cases) in the preterm neonates group while 27.59% (8/29 cases) in the full-term neonates group.There was no significant difference in mortality rate between each group (χ2=0.218, P=0.640). The primary diseases were RDS (9/9 cases, 100%) and MAS (4/8 cases, 50%) in preterm and full-term neonates who died of PPHN, respectively.One case of pulmonary hypertensive vascular remodeling, 1 case of alveolar capillary dysplasia (ACD) and 1 case of interstitial pneumonia were found in 3 lung samples of neonates died of PPHN. Conclusions The ratio of preterm increased in neonates with PPHN.RDS and infection were the first two primary diseases in preterm neonates with PPHN.MAS was the first primary disease in full-term neonates with PPHN.Primary pulmonary hypertension should be considered for neonates with severe PPHN. Key words: Persistent pulmonary hypertension; Infant, newborn; Risk factor; Primary persistent pulmonary hypertension