A population-based study of the risk of repeat clinical chorioamnionitis in Washington State, 1989-2008

Chorioamnionitis can cause severe complications for the infant; therefore, characterization of the risk of recurrence and identification of the factors that modify it are clinically relevant to pregnant women and their providers.

The risk of recurrence was examined in a retrospective population-based cohort study with the use of birth certificate and delivery hospitalization discharge data from Washington State for the years 1989-2008.

Women who had chorioamnionitis in their first deliveries were 3.43 times as likely to have chorioamnionitis in their second deliveries as were women who did not have chorioamnionitis in their first deliveries (95% confidence interval [CI], 2.67-4.42; P < .001). Smoking status modified this association (smokers: odds ratio, 1.38 [95% CI, 0.62-3.08]; nonsmokers: odds ratio, 3.80 [95% CI, 2.88-5.00]).

These data provide strong evidence for the occurrence of repeat chorioamnionitis; the association is strongest in women who do not smoke during pregnancy.