Association of the vaginal microbiota with pregnancy outcomes in Chinese women after cervical cerclage

Research question The study aimed to investigate the relationship between risk factors associated with vaginal microbiota and outcomes of cervical cerclage. Design A retrospective cohort study of singleton pregnancies with cervical cerclage was conducted. Before cerclage, participants underwent a vaginal microbiota assay, including morphological examination and functional vaginal microecological analysis using a vaginitis multi-test kit. The chi-squared test and logistic and linear regression analyses were performed to evaluate the associations of various risk factors with maternal and neonatal outcomes. Results Eighty-five participants were included. The mean interval between cerclage and delivery was 69.4 ± 36.7 days, and 12 (14.1%) of newborns died. A higher grade of vaginal cleanliness, a higher pH, a lower abundance of Lactobacillus spp., a higher sialidase-positive percentage, a higher positive percentage of clue cells, a higher lactobacillary grade, a higher Nugent score and a higher rate of microecological dysbiosis were significantly associated with a poor neonatal outcome and shorter cerclage to delivery intervals (P < 0.001–0.041). Furthermore, sialidase positivity was associated with the highest risk of cervical cerclage failure (odds ratio [OR] 10.469; 95% confidence interval [CI] 1.096–36.087), followed by the presence of bulging membranes (OR 6.400; 95% CI 0.428–15.641) and vaginal microbiota dysbiosis (OR 6.038; 95% CI 0.173–17.072). Conclusions An absence of Lactobacillus spp. and some functional factors of vaginal microbiota are potential risk factors that predict subsequent cerclage failure. These findings indicate the potential clinical utility of these factors to predict cervical cerclage failure for managing patient expectations and providing improved postoperative surveillance.