Preterm Birth

Overview

Preterm birth (<37 weeks gestation) is the leading cause of neonatal mortality and morbidity worldwide (~15 million/year). The vaginal microbiome is a key determinant of preterm birth risk — Lactobacillus-depleted vaginal communities (CST-IV, enriched in gardnerella, atopobium, sneathia, megasphaera, prevotella) are associated with increased risk of ascending infection, cervical inflammation, and preterm delivery ^[1].

Microbiome Connection

Protective: lactobacillus crispatus (CST-I) dominance — lowest preterm risk via D-lactic acid production and barrier maintenance.
Risk: CST-IV (BV-associated) communities → ascending infection → chorioamnionitis → preterm labor.
Ureaplasma: Colonization in preterm infants associated with bronchopulmonary dysplasia ^[2].

Metal Connection

Prenatal trace element exposure affects infant gut microbiome programming and preterm birth risk ^[3].
Nickel in preterm formula may fuel pathogen expansion contributing to necrotizing enterocolitis post-delivery ^[2].
Statins explored for preterm delivery prevention ^[4].

Cross-References

bacterial vaginosis — BV as primary preterm risk factor
lactobacillus crispatus — protective CST-I dominance
necrotizing enterocolitis — consequence in preterm survivors
ureaplasma — preterm colonization and BPD
gestational diabetes — GDM increases preterm risk

References (4)

Pamela Pruski, Gonçalo D. S. Correia, Holly V. Lewis et al. (2021). Pruski & Correia 2021 — Direct On-Swab Metabolic Profiling of Vaginal Microbiome Host Interactions During Pregnancy and Preterm Birth. Nature Communications. doi:10.1038/s41467-021-26215-w
Karen Pendergrass (2026). Nickel as a Catalytic Driver of Necrotizing Enterocolitis: Dietary Nickel, Microbial Metallomics, and the Activation of Nickel-Dependent Virulence Pathways in the Preterm Gut. Zenodo Preprint. doi:10.5281/zenodo.18200348
Shimao Xiong, Bing Xie, Naiyi Yin et al. (2025). Xiong 2025 — Prenatal Exposure to Trace Elements Impacts Mother-Infant Gut Microbiome, Metabolome and Resistome During the First Year of Life. Nature Communications. doi:10.1038/s41467-025-60508-8
Eleanor Whitaker (2021). Whitaker 2021 — Could Statins Be a Novel Therapeutic for the Prevention of Preterm Delivery? Evidence from an Animal Model and Phase II Feasibility Trial. University of Edinburgh (PhD thesis)