A case-referent study on fetal bacteremia and late fetal death of unknown etiology in Lithuania

Background. The objectives were to test the hypothesis that certain strains of microorganisms are present in fetal blood in a significant proportion o f parturient women suffering unexplained third trimester fetal death, and t o examine the correlation between fetal bacteremia and histologic chorioamn ionitis and vasculitis. Methods. A case-referent study was carried out on 58 pregnant women with fe tal death of unknown etiology (cases) and 116 pregnant women at term (refer ents) with live fetuses. Cultures from maternal endocervix, amniotic fluid, placental homogenate, external ear and blood of newborns were performed in both groups. Histological examination of placentas and fetal membranes was carried out in order to identify chorioamnionitis and chorionic vasculitis . Results. Intrauterine fetal bacteremia was observed in 36% of cases and in 0% of referents (p= 0.001). Escherichia coli was the most common strain, is olated in 21% of fetal blood samples in cases. Extensive histologic chorioa mnionitis was observed in 50% of cases with the presence of Escherichia col i in blood of stillborns. Chorionic vasculitis was found in 67% of such cas es. Positive significant correlations between isolation of the Escherichia coli from maternal endocervix, amniotic fluid, placenta, fetal ear and bloo d in stillborns and histological chorioamnionitis and chorionic vasculitis were observed. Conclusions. Escherichia coli bacteremia was detected in a significant prop ortion of stillborns suffering a third trimester prelabor death. Fetal bact eremia significantly correlated with histologic signs of inflammation in pl acenta and membranes. Ascending subclinical intrauterine infection may Flay an important role in the etiology of otherwise unexplained late prelabor f etal death.