International Journal of Pediatrics Research

Objective The purpose of this study was to investigate the relationship between the changes of vaginal flora and preterm labor in pregnant women with imbalanced maternal fetal immunity. How: Thirty preterm pregnant women (<37 weeks gestation) and 30 full-term pregnant women (≥37 weeks gestation) admitted to the obstetrics Department of our hospital from January 2021 to December 2021 were included. Vaginal swabs were collected before delivery, microbial DNA was extracted, and 16S rRNA sequencing was performed. Shannon index, OTU number and Faiths PD index were used to evaluate microbial diversity, richness and evolutionary diversity, respectively. The distribution of FoxP3 protein was observed by immunohistochemical staining of placenta, and its average cumulative optical density was calculated to understand the distribution of Treg cells. Results: The Shannon index (2.35±0.43) in the preterm pregnant women group was lower than that in the full-term pregnant women group (3.12±0.50), P<0.05. The mean OTU number in the preterm pregnant women group (432.11±58.22) was lower than that in the full-term pregnant women group (509.12±65.32), P<0.05. The Faiths PD index of preterm pregnant women (15.71±3.41) was lower than that of full-term pregnant women (18.92±4.22), P<0.05. Compared with the full-term placenta group (0.201±0.13), the preterm placenta group (0.168±0.12) had a lower average cumulative optical density of FoxP3 protein. Conclusion: The diversity, richness and evolutionary diversity of vaginal flora in preterm pregnant women are decreased, which may affect the maintenance of pregnancy by changing the distribution of Treg cells, thus leading to preterm birth.

Maternal fetal immune imbalance; Maternal flora; Treg cells; Premature.