ORIGINAL RESEARCH article
Front. Med.
Sec. Obstetrics and Gynecology
This article is part of the Research TopicMaternal and Infant Microbiota during Gestation and the Postpartum PeriodView all 3 articles
The Impact of Vaginal Microbiota on Preterm Birth in Early Pregnancy
Provisionally accepted
- 1Yantaishan Hospital, Yantai, China
- 2Zhifu District Maternal and Child Health Hospital, Yantai, China
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Background: Dysbiosis of the vaginal microbiota adversely affects women ' s health and is associated with negative pregnancy outcomes. Understanding its role in early pregnancy is critical for predicting and preventing preterm birth (PTB). Objective: This study aimed to compare vaginal microbiota profiles in early pregnancy between women who delivered preterm and those who delivered at term, and to evaluate the predictive value of microbial markers for PTB. Methods: We conducted a retrospective cohort study involving 180 pregnant women diagnosed with threatened preterm labor who delivered at our hospital between June 2023 and November 2024. Gestational age was confirmed using last menstrual period and early transvaginal ultrasound. Participants were categorized into preterm (delivery < 37 weeks, n = 89) and full-term (delivery ≥37 weeks, n = 91) groups. Results: There were no significant differences in maternal age, parity, or obstetric history between the two groups (all p > 0.05). As expected, gestational age at delivery and neonatal birth weight were significantly lower in the preterm group (both p < 0.001). Vaginal pH was significantly higher in the preterm group (5.60 ± 0.98 vs. 4.58 ± 0.98, p < 0.05). Microbial dysbiosis and aerobic vaginitis (AV) were more prevalent in the preterm group. The relative abundance of Lactobacillus was reduced, whereas Gardnerella, Prevotella, Streptococcus, Mycoplasma, and Fusobacterium were enriched in preterm deliveries. The combination of Gardnerella and Prevotella showed promising predictive value for PTB, with an area under the curve (AUC) of 0.866. Conclusion: Vaginal microbiota dysbiosis and decreased Lactobacillus abundance in early pregnancy are associated with an increased risk of preterm birth. Screening vaginal microbiota during early pregnancy may help identify women at high risk for PTB.
Keywords: early pregnancy, Preterm Birth, Term Birth, vaginal microbiota, pH, Aerobic vaginitis, prediction
Received: 29 Apr 2025; Accepted: 06 Oct 2025.
Copyright: © 2025 Zhang, Yu, Yi, Zhang, Shi and Dong. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
* Correspondence: Pingping Dong, aa1254113@163.com
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