Chorioamnionitis in the Development of Cerebral Palsy: A Meta-analysis and Systematic Review

CONTEXT: Chorioamnionitis (CA) has often been linked etiologically to cerebral palsy (CP). OBJECTIVES: To differentiate association from risk of CA in the development of CP. DATA SOURCES: PubMed, Cochrane Library, Embase, and bibliographies of original studies were searched by using the keywords (chorioamnionitis) AND ((cerebral palsy) OR brain). STUDY SELECTION: Included studies had to have: (1) controls, (2) criteria for diagnoses, and (3) neurologic follow-up. Studies were categorized based on: (1) finding incidence of CP in a CA population, or risk of CP; and (2) incidence of CA in CP or association with CP. DATA EXTRACTION: Two reviewers independently verified study inclusion and extracted data. RESULTS: Seventeen studies (125 256 CA patients and 5 994 722 controls) reported CP in CA. There was significantly increased CP inpreterm histologic chorioamnionitis (HCA; risk ratio [RR] = 1.34, P < .01), but not in clinical CA (CCA). Twenty-two studies (2513 CP patients and 8135 controls) reported CA in CP. There was increased CCA (RR = 1.43, P < .01), but no increase in HCA in preterm CP. Increased HCA was found (RR = 4.26, P < .05), as well as CCA in term/near-term CP (RR = 3.06, P < .01). CONCLUSIONS: The evidence for a causal or associative role of CA in CP is weak. Preterm HCA may be a risk factor for CP, whereas CCA is not. An association with term and preterm CP was found for CCA, but only with term CP for HCA.