Actinomyces in Pregnancy: A Review of the Literature.

IMPORTANCE: Actinomyces is commonly found in many areas of the body where it derives a benefit without harming the host. When it does infect the host during pregnancy, is that infection a threat to the obstetric patient and does that infection cause adverse pregnancy outcomes?

OBJECTIVE: The aim of this study was to review what is known about Actinomyces infections and the impact of an Actinomyces infection on pregnancy outcomes.

EVIDENCE ACQUISITION: A PubMed search was undertaken with the search years unlimited to April 1, 2016, and restricted to articles in English. The search terms included "actinomyces," "pregnancy," "prenatal," "maternal," "actinomyces infection," "pregnancy," "chorioamnionitis," "preterm labor," "premature birth," or "postpartum actinomyces."

RESULTS: Eighteen of the 154 identified articles are the basis of this review. Actinomyces is a rod-like positive bacterium. The diagnosis of an Actinomyces infection can be by culture or Gram stain. Actinomyces is commensal and typically only infects after a mucosal break or lesion. Seventeen cases were identified in pregnancy. Ten cases were complicated by chorioamnionitis and a preterm delivery. A nidus leading to infection was identified in 12 of the cases including women with a cervical cerclage, dental abscesses, appendicitis, renal actinomycosis, and ovarian abscesses. Adverse pregnancy outcomes have been linked with periodontal disease, but treatment did not prevent preterm delivery in a randomized, blinded, controlled trial.

CONCLUSIONS: Actinomyces infections in pregnancy are rare but, if they occur, have been linked primarily with preterm deliveries.

TARGET AUDIENCE: Obstetricians and gynecologists, family physicians.

LEARNING OBJECTIVES: After completing this activity, the learner should be better able to identify the areas of the body where Actinomyces infections occur and how the infections typically occur, identify the pathophysiologic changes that occur during pregnancy that might lead to an Actinomyces infection and how that infection may affect pregnancy outcomes, and describe the treatment for mild and severe Actinomyces infections.