To investigate the prognostic role of concomitant histologic fetal inflammatory response
with chorioamnionitis on neonatal outcomes through a systematic review and meta-analysis
of existing literature.The primary search was conducted on October 17th, 2021, and
it was updated on May 26th, 2023, across four separate databases (MEDLINE, CENTRAL,
Embase, and SCOPUS) without using any filters.Observational studies reporting obstetrical
and neonatal outcomes of infant-mother dyads with histological chorioamnionitis and
histologic fetal inflammatory response in comparison to histological chorioamnionitis
alone were eligible. We included studies that enrolled only preterm neonates, born
before the 37th gestational week, or very low birth weight neonates (birthweight <
1500 g). The protocol was registered with the International Prospective Register of
Systematic Reviews (CRD42021283448).The records were selected by title, abstract,
and full text, and disagreements were resolved by consensus. Random-effect model-based
pooled odds ratios with corresponding 95% confidence intervals were calculated for
dichotomous outcomes.In total of 50 studies were identified. Quantitative analysis
of 14 outcomes was performed. We conducted subgroup analysis using mean gestational
age of the studies, and we implemented the 28th gestational week as a cut off line.
Among neonates with lower gestational ages, early-onset sepsis (pooled odds ratio
2.23; 95% confidence interval, 1.76-2.84). and bronchopulmonary dysplasia was associated
(pooled odds ratio 1.30; 95% confidence interval, 1.02 to 1.66) with the histologic
fetal inflammatory response. Our analysis showed that preterm neonates with a concomitant
histologic fetal inflammatory response are more likely to develop intraventricular
hemorrhage (pooled odds ratio 1.54; 95% confidence interval, 1.18 to 2.02) and retinopathy
of prematurity (pooled odds ratio 1.37; 95% confidence interval, 1.03 to 1.82). Among
infant-mother dyads with histologic fetal inflammatory response, the odds of clinical
chorioamnionitis were almost three-fold higher (pooled odds ratio 2.99; 95% CI, 1.96
to 4.55) than in the histological chorioamnionitis alone group.Investigating multiple
neonatal outcomes, we found a statistically significant association in the case of
four major morbidities: early-onset sepsis, bronchopulmonary dysplasia, intraventricular
hemorrhage and retinopathy of prematurity.
