Re-evaluation of chorioamnionitis and funisitis with a special reference to subacute chorioamnionitis.

Our purpose is to prove that prolonged inflammation of the chorionic plate, which we have termed subacute chorioamnionitis (SCAM), is a distinctive entity and should be differentiated from acute chorioamnionitis (ACAM) because it is an excellent prognostic indicator of chronic lung disease (CLD), including Wilson-Mikity syndrome (WMS). Ninety singleton placentas with stage-3 chorioamnionitis were delivered at 23 to 32 weeks of gestation during 1993 to 1996, and the infants survived more than 28 days. There were 49 placentas with stage 3 SCAM, 33 placentas with stage 3 ACAM, and 8 placentas with subacute necrotizing funisitis (SNF) and without inflammation of the chorionic plate. Fifty-three of gestation- and birthweight-matched placentas without chorioamnionitis were selected as control. To determine the risk factors for CLD, 27 clinical and 6 histological variables were analyzed. Logistic regression analysis showed that amniotic necrosis (AN) (P =.0168) and low birthweight (P =.0341) were the major contributing risk factors for CLD. SNF was not significantly related to CLD. Patients with SCAM (AN+, SNF-) were highly susceptible to CLD. In conclusion, SCAM, especially when associated with AN, seems to be a unique prognostic indicator of CLD.