Intra-amniotic infection is often the cause of a second-trimester abortion.
The bacterial species involved include bacteria with low pathogenicity lik
e Ureaplasma urealyticum and various Mycoplasma species. In this case we de
scribe an intra-amniotic infection caused by Capnocytophaga sputigena, ofte
n found in the normal bacterial flora of the oral cavity, but not in the va
gina. Oral sex during pregnancy was the most probable source of the infecti
on. The aborted fetus showed signs of pneumonia upon histologic examination
. The bacterial species was identified using broad-spectrum 16S rDNA polyme
rase chain reaction (PCR) directly from the amniotic fluid and after bacter
ial culture. Amniotic fluid glucose was below detection level, confirming t
he presence of an intra-amniotic infection.