Abstract
OBJECTIVES: To explore the correlation between changes in oral and vaginal/intestinal microbiota during pregnancy and threatened preterm birth, providing a theoretical basis for further mechanism research. METHODS: The study retrospectively analyzed pregnant women who gave birth in the gynecological outpatient department of a medical university affiliated hospital in East China from December 2021 to September 2022. The case group included pregnant women who experienced regular or irregular uterine contractions (with the cervical canal gradually shortening but the cervical opening not exceeding 1 cm) within 24 to 28 weeks of pregnancy and were at risk of preterm birth; The control group included individuals without such symptoms. Two sets of deoxyribonucleic acids (DNA) were extracted from oral and vaginal/intestinal microbiota, and bioinformatics (BI) methods were used to sequence and analyze these three sets. RESULTS: Oral microbiota analysis showed significant differentiation between two groups, with significant clustering within each group. Vaginal microbiota analysis revealed enrichment of specific bacteria in Group D compared to Group C. Gut microbiota analysis showed varying proportions of different genera in Group E and F. Significant differences were observed in species composition between the groups. CONCLUSIONS: (1) Compared to normal and healthy pregnant women, there was a significant imbalance in the diversity of oral microbiota in patients with threatened premature delivery. (2) The overall composition and structure of vaginal microbiota in patients with threatened premature delivery have changed. The relative abundance of probiotic lactobacilli in the vaginal microbiota decreased in the case group. (3) There was no significant difference in the overall community structure of gut microbiota in patients with threatened premature delivery compared to normal pregnant women.