Chorioamnionitis: the association between clinical and histological diagnosis

Objective: To determine the association between clinical and histological diagnoses of chorioamnionitis.Methods: A retrospective 9-year review of hospital records for all perinatal deaths (N = 804) occurring at a Western New York regional perinatal center between 1988 and 1996 was conducted. Information concerning clinical indicators of chorioamnionitis were recorded including: maternal fever, leukocytosis, uterine tenderness, foul smelling discharge, and fetal tachycardia. Histological examination of the placenta was conducted in 797 of 804 perinatal deaths and staged by a standardized method. Type and number of clinical signs and symptoms were correlated with severity of histologic grade to determine their relation.Results: Chorioamnionitis was diagnosed either clinically or histologically in 243 (30.5%) of 797 perinatal deaths. Of these, 72 cases (23.5%) occurred in the 307 fetal deaths and 171 (34.9%) occurred in the 490 neonatal deaths. Five cases were diagnosed only on autopsy. In 51 of 243 cases (21%) there was histologic confirmation of chorioamnionitis without any clinical indicators present. In 13 of 243 cases (5.4%) there were 1 or more clinical indicators of chorioamnionitis without histologic confirmation. Sensitivity and specificity for 1 or more clinical indicators was 77.8% and 97.7%, respectively.Conclusion: Chorioamnionitis was present in 30.5% of perinatal deaths in this cohort. Identification of one or more clinical signs or symptoms was found to be both a sensitive and specific screening method for a presumptive diagnosis of chorioamnionitis when using histologic confirmation as the gold standard.