Chorioamnionitis: a study of organisms isolated in perinatal autopsies

The purpose of this study was to determine the validity of postmortem cultures in perinatal autopsies; in particular, those cases where there is gross or histologic evidence of chorioamnionitis. Lung, liver, blood, and placental cultures were obtained from 159 neonatal autopsies with histologic evidence of chorioamnionitis at Magee-Women's Hospital between January 1980 and July 1985. The criterion for chorioamnionitis was a polymorphonuclear leukocytic infiltrate in the placental membranes. The neonates studied were 63 percent white and 36 percent black; the male to female ratio was 83 to 76. Intrauterine fetal death occurred in 43 percent of the cases. The mean gestational age was 24 weeks. Premature labor occurred in 64 percent of the cases, and 70 percent of the cases presented with premature rupture of fetal membranes. Congenital pneumonia (defined by the presence of polymorphonuclear leukocytes in the alveolar spaces) was present in 45 percent of cases. The lung was the most frequent site cultured; the four most frequently isolated organisms were: Staphylococcus epidermidis--18 percent; Beta Streptococcus Group B--13 percent; E. coli--nine percent; Ureaplasma urealyticum--nine percent. Negative cultures from multiple sites occurred in seven percent of cases. The results of this investigation indicate that multi-organ cultures help in defining the role of a particular bacteria as a pathogen, and that Staphylococcus epidermidis may be a true fetal pathogen under certain conditions. It is recommended that cultures for Chlamydia trachomatis not be done on fetal tissues.