Acute Placental Villitis as Evidence of Fetal Sepsis: An Autopsy Case Report.

Acute placental villitis is very rare and believed to reflect overwhelming fetal sepsis in utero, commonly caused by Escherichia coli or group B streptococci. We present a case of intrauterine fetal death associated with acute placental villitis and acute necrotizing chorioamnionitis by early-onset group B streptococcal infection. A 36-year-old woman presented with decreased fetal movement and fever at 21 weeks of gestation. Ultrasound demonstrated intrauterine fetal death. After delivery, the placenta revealed multifocal neutrophilic infiltration in chorionic villi, most prominently beneath the trophoblast basement membrane, which was also accompanied by acute necrotizing chorioamnionitis. Gram-positive microorganisms were detected in villous vessels as well as in the major organs of the fetus, which was consistent with Streptococcus agalactiae (group B) cultured from maternal blood. Acute placental villitis should be recognized as evidence of fetal sepsis that often has lethal clinical outcome, as compared to intra-amniotic infection associated with acute chorioamnionitis alone.