Short-Term Outcomes of Expectant Management With Antibiotics for Preterm Subclinical Intra-Amniotic Infection

This study assessed the efficacy of expectant management with antibiotics in patients with intra-amniotic infections diagnosed and treated at our institution. Antimicrobial and corticosteroid treatments were initiated for patients with intra-amniotic inflammation and a high infection risk, and the diagnosis was confirmed 2 days later by culture results, including Ureaplasma spp. and Mycoplasma hominis, which guided further treatment.

This retrospective cohort study included singleton pregnant women diagnosed with intra-amniotic infection between 20 + 0 and 33 + 6 weeks of gestation between 2014 and 2021. Intra-amniotic inflammation was defined as an interleukin-6 concentration of ≥ 3.0 ng/mL in amniotic fluid, and intra-amniotic infection was confirmed by positive amniotic fluid cultures combined with inflammation. First-line antimicrobial therapy consisted of sulbactam/ampicillin and azithromycin. Primary outcome was the proportion of patients in which pregnancy was prolonged beyond 48 h without exacerbation of intra-amniotic inflammation. Secondary outcome was prolonged pregnancy beyond 168 h.

Of 56 diagnosed patients, 45 were analyzed. Pregnancy was prolonged beyond 48 h without exacerbation in 71.9% of the women in a Ureaplasma spp./Mycoplasma hominis-only group compared with 23.0% in the other bacterial group (p = 0.006). Pregnancy was significantly prolonged beyond 168 h in the Ureaplasma spp./Mycoplasma hominis-only group compared with that in the other bacterial group (28.1% vs. 0%, p = 0.04).

Expectant management with antibiotics is feasible in the short term for subclinical intra-amniotic infections caused solely by Ureaplasma spp./Mycoplasma hominis. However, for cases caused by the other bacteria, further studies are needed to determine appropriate management strategies.