Impact of subclinical chorioamnionitis on maternal and neonatal outcomes

Chorioamnionitis is considered to be one of the main causes of preterm labor and has been associated with an adverse perinatal outcome in preterm infants. The controversy about the benefits/risks of delaying labor is a critical issue concerning the management of chorioamnionitis.

The database between July 2001 and March 2006 was reviewed for women with singleton pregnancies between 22 and 28 weeks of gestation and with chorioamnionitis diagnosed on admission by amniotic fluid neutrophil elastase level. Women were classified according to the severity of chorioamnionitis (group A, amniotic fluid neutrophil elastase level of 0.15-1 microg/ml; B, 1-10 microg/ml; and C, > or = 10 microg/ml). During expectant management, serum C-reactive protein levels monitored the remission and aggravation of chorioamnionitis. Following deliveries, placentas were examined for histologic chorioamnionitis.

One hundred women were enrolled (group A, 38; B, 34; C, 28). The latency period until delivery was significantly longer in group A than in groups B and C. C-reactive protein levels just before delivery were higher than those on admission in 61% of the overall cases. Histologic chorioamnionitis and funisitis were manifested in 90.4% and 65.5%, respectively. Intrauterine fetal demise (4 cases) and neonatal and postneonatal deaths during admission (10 cases) were observed. Bronchopulmonary dysplasia was the most common major morbidity noted in groups B and C.

Chorioamnionitis could be controlled but is hard to cure. Higher levels of amniotic fluid neutrophil elastase are associated with a shorter interval from admission to delivery in women with subclinical chorioamnionitis.