Histologic Chorioamnionitis and Bronchopulmonary Dysplasia in Preterm Infants: The Epidemiologic Study on Low Gestational Ages 2 Cohort.

OBJECTIVE: To investigate the association between histologic chorioamnionitis (HCA) and bronchopulmonary dysplasia (BPD) in very preterm infants, both in a general population and for those born after spontaneous preterm labor and after preterm premature rupture of membranes (pPROM). STUDY DESIGN: This study included 2513 live born singletons delivered at 24-31 weeks of gestation from a national prospective population-based cohort of preterm births; 1731 placenta reports were available. HCA was defined as neutrophil infiltrates in the amnion, chorion of the membranes, or chorionic plate, associated or not with funisitis. The main outcome measure was moderate or severe BPD. Analyses involved logistic regressions and multiple imputation for missing data. RESULTS: The incidence of HCA was 28.4% overall: 38% in cases of preterm labor, 64% in cases of pPROM, and less than 5% in cases of vascular disorders. Overall, the risk of BPD after adjustment for gestational age, sex, and antenatal steroids was reduced for infants with HCA (HCA alone: aOR 0.6 [95% CI 0.4-0.9]; associated with funisitis: aOR 0.5 [95% CI 0.3-0.8]). This finding was explained by the high rate of BPD and low rate of chorioamnionitis among children with fetal growth restriction. HCA was not associated with BPD in the preterm labor (13.4% vs 8.5%; aOR 0.9; 95% CI 0.5-1.8) or in the pPROM group (12.9% vs 12.1%; aOR 0.6; 95% CI 0.3-1.3). CONCLUSION: In homogeneous groups of infants born after preterm labor or pPROM, HCA is not associated with BPD.

Impact of fetal growth restriction on mortality and morbidity in a very preterm birth cohort.

OBJECTIVE: To assess the impact of being small for gestational age (SGA) on very preterm mortality and morbidity rates by using different birthweight percentile thresholds and whether these effects differ by the cause of the preterm birth. STUDY DESIGN: The study included singletons and twins alive at onset of labor between 24 and 31 weeks of gestation without congenital anomalies from the Models of Organising Access to Intensive Care for very preterm births very preterm cohort in 10 European regions in 2003 (n = 4525). Outcomes were mortality, intraventricular hemorrhage grade III and IV, cystic periventricular leukomalacia, and bronchopulmonary dysplasia (BPD). Birthweight percentiles in 6 classes were analyzed by pregnancy complication. RESULTS: The mortality rate was higher for infants with birthweights <25th percentile when compared with the 50th to 74th percentile (adjusted odds ratio, 3.98 [95% CI, 2.79-5.67] for <10th; adjusted odds ratio, 2.15 [95% CI, 1.54-3.00] for 10th-24th). BPD declined continuously with increasing birthweight. There was no association for periventricular leukomalacia or intraventricular hemorrhage. Seventy-five percent of infants with birthweights <10th percentile were from pregnancies complicated by hypertension or indicated deliveries associated with growth restriction. However, stratifying for pregnancy complications yielded similar risk patterns. CONCLUSIONS: A 25th percentile cutoff point was a means of identifying infants at higher risk of death and a continuous measure better described risks of BPD. Lower birthweights were associated with poor outcomes regardless of pregnancy complications.