Reversal of intra-amniotic Chlamydia trachomatis antigen status

Chlamydia trachomatis (CT) infection in pregnant women is related to unfavorable obstetric outcomes such as prematurity, intrauterine growth retardation, and stillbirth. A 22-year-old woman underwent transabdominal amniocentesis at 16 weeks of gestation (GW). A CT antigen test using polymerase chain reaction in the amniotic fluid was found to be positive, though the patient had no symptom of infection. Beginning at 20 GW, clarithromycin was orally administered at a dose of 400 mg/day for 2 weeks. The CT antigen test in amniotic fluid at 28 GW turned to a negative result. A female baby was vaginally born at 38 GW by spontaneous labor. The CT antigen test of her gastric contents showed a negative result and anti-CT IgM in umbilical cord blood was negative. Neither respiratory distress, pneumonia, nor conjunctivitis was detected. To the best of our knowledge, this case is the first report showing the reversal of the intra-amniotic CT antigen status by antibiotic treatment.