Eradication of intra-amniotic Streptococcus mutans in a woman with a short cervix.

Background: Microbial invasion of the amniotic cavity (MIAC) remains an important pathogenetic factor in preterm births. Although most MIACs seem to originate in vaginal microflora, other reservoirs such as the oral microflora have been suggested.

Case: We report a case of successful eradication of Streptococcus mutans (a bacterium generally found in dental plaque) from the amniotic cavity, using ampicillin, gentamycin, and azythromycin in a woman who presented with threatened preterm labour and a short cervix at 25 weeks' gestation. She delivered at 34 weeks' gestation and was treated for tooth decay 12 weeks after delivery.

Conclusion: Intra-amniotic infection should be suspected in the presence of a short cervix during the second trimester. Appropriate parenteral antibiotics can eradicate intra-amniotic infection and potentially prolong pregnancy.