Evaluation of Postnatal Complications in Clinical and Histological Chorioamnionitis in Extremely Preterm Infants: A Japanese Cohort Study.

OBJECTIVE:Terminating pregnancy appropriately before the intrauterine infection has progressed may have an improved prognosis for preterm infants. We evaluate how the combination of histological chorioamnionitis (hCAM) and clinical chorioamnionitis (cCAM) affects the short-term prognosis of infants. STUDY DESIGN:This retrospective multicenter cohort study based on the Neonatal Research Network of Japan included extremely preterm infants born weighing <1,500 g between 2008 and 2018. Demographic characteristics, morbidity, and mortality were compared between the cCAM(-)hCAM(+) and cCAM(+)hCAM(+) groups. RESULTS:We included 16,304 infants. The progression to cCAM in infants with hCAM was correlated with the increase in home oxygen therapy (HOT) (adjusted odds ratio [aOR], 1.27; 95% confidence interval [CI], 1.11-1.44) and persistent pulmonary hypertension of the newborn (PPHN) (1.20, 1.04-1.38). Furthermore, increased progression of the hCAM stage in infants with cCAM correlated with an increase in bronchopulmonary dysplasia (BPD; 1.05, 1.01-1.11), HOT (1.10, 1.02-1.18), and PPHN (1.09, 1.01-1.18). However, it had a negative impact on hemodynamically significant patent ductus arteriosus (hsPDA; 0.87, 0.83-0.92) and death before discharge from the neonatal intensive care unit (NICU; 0.88, 0.81-0.96). CONCLUSION:Progression to cCAM in infants with hCAM positively correlated with HOT and PPHN. Progression of hCAM staging in infants with cCAM further increases the prevalence of BPD and the need for HOT and PPHN while reducing the prevalence of hsPDA and death before discharge from the NICU. The effects of the progressive hCAM stage in infants with cCAM vary from positive to negative by disease. KEY POINTS:· Retrospective multicenter cohort study based on the Neonatal Research Network of Japan.. · Clinical and histological chorioamnionitis increases the prevalence of BPD, HOT, and PPHN.. · Progression of histological chorioamnionitis in infants reduces the prevalence of hsPDA and death..