Strengths and Limitations
Our study has some limitations. First, since we analyzed the
relationship between the results of vaginal culture at admission and
neonatal outcomes, our analysis did not consider antibiotic treatment
during hospitalization, which may affect the neonatal outcomes. Second,
although cerclage was identified as a risk factor for ESBL-E vaginal
colonization, the causality is uncertain. In fact, a previous study has
demonstrated that the proportion of Lactobacillus spp. was
reduced, while that of abnormal vaginal flora increased before rescue
cerclage.28 Considering this result, the possibility
that ESBL-E vaginal colonization had already occurred before the
operation could not be excluded because information on vaginal culture
before cerclage was not available in this study population.
To the best of our knowledge, this is the first study to identify
changes in the prevalence and risk factors of ESBL-E vaginal
colonization in high-risk pregnancies. Our study is also meaningful in
that we included a relatively large number of patients who underwent
vaginal culture according to the protocol of our institution. In
addition, the need for further studies on the treatment of ESBL-E
colonization and pregnancy outcomes was identified in this study. For
example, there are only a few randomized controlled trials on ESBL-E
infection treatment, and there are many controversies on whether
antibiotic treatment for ESBL-E infection is effective or on which
treatment methods are effective.45,46