Chorioamnionitis and respiratory outcomes in prematurely born children: a systematic review and meta analysis.

Introduction: To conduct a systematic review and meta-analysis of the association between chorioamnionitis and respiratory outcomes of prematurely born children.

Content: Pubmed, Medline and Embase were searched for relevant studies. Studies were included if they assessed prematurely born children, who had been exposed to chorioamnionitis and had either lung function testing or assessment of wheeze or asthma following NICU discharge. Two reviewers independently screened the search results, applied inclusion criteria and assessed methodological quality. One reviewer extracted the data and these were checked by a second reviewer.

Summary: A total of 1,237 studies were identified, but only eight which included 35,000 infants, fulfilled the inclusion criteria. One study looked at both lung function results and wheeze or asthma in childhood. Four of five studies found an association between wheeze/asthma in childhood and exposure to chorioamnionitis: the overall Odds Ratio (OR) for developing wheeze/asthma in childhood was OR 1.71 (95 % CI: 1.55-1.89). Four studies looked at lung function in childhood, three of which showed no statistically significant association between chorioamnionitis exposure and altered lung function. One study found lower lung function in those exposed to chorioamnionitis and lower expiratory flows with increasing levels of chorioamnionitis (forced expiratory flow at 50 % of exhaled forced vital capacity (=FEF₅₀) p=0.012, forced expiratory flow at 25-75 % of the forced vital capacity is exhaled (=FEF_25-75) p=0.014).

Outlook: There was a significant association between chorioamnionitis and the development of wheeze or asthma in childhood, but overall not in impairment of lung function.