Miss Mikayla Li1,2, Dr Xin-Yi Chua3, Dr Amanda Henry1,2,4, Dr Gregory Davis1,2, Dr Daniella Susic2,3
1Department of Women's and Children’s Health, St George Hospital, Sydney, Australia, 2Discipline of Women's Health, School of Clinical Medicine, University of New South Wales Faculty of Medicine and Health, Sydney, Australia, 3Microbiome Research Centre, University of New South Wales Faculty of Medicine, Sydney, Australia, 4The George Institute for Global Health, University of New South Wales, Sydney, Australia
Biography:
Mikayla Li is a 5th year UNSW medical student with a long-standing interest in obstetrics and gynaecology. Last year, she received first-class honours for her research on the human vaginal microbiome and its associations with pregnancy complications. She is currently the president of the Women and Children’s Society at UNSW.
Abstract:
Background and Aim: Knowledge about the vaginal microbiome and its significance in pregnancy is progressing, but there is a lack of longitudinal studies investigating associated pregnancy complications. This sub-study assessed microbial signatures within the vaginal microbiome in trimesters one (T1) and three (T3) that are linked to hypertensive disorders of pregnancy (HDP) [preeclampsia (PE) or gestational hypertension (GH)] and/or gestational diabetes mellitus (GDM).
Methods: Maternal vaginal samples were self-collected using a 5 second vaginal swab from the mid-vagina. Samples were collected from the same 98 women at T1 (≤13 weeks) and T3 (32-36 weeks). DNA was extracted at the Microbiome Research Centre (MRC) at UNSW, Sydney. Shotgun metagenomic sequencing (WGS) was performed at the Ramacciotti Centre, UNSW, Sydney. Bioinformatic microbiota profiling was conducted using Metagenomic Phylogenetic Analysis 2 (MetaPhlan2)¹ and statistical analyses for microbiome and diversity data were performed using R (v4.0.2)² at the MRC.
Results: The vaginal microbiome analysis showed no significant association between alpha or beta diversity measurements and HDP or GDM. Species level analysis revealed a significant association with GDM and Peptoniphilus harei (p=0.016) in T1 and Lactobacillus gasseri (p=0.028) prior to a GDM diagnosis being made, and Corynebacterium kroppenstedtii (p=0.028) in T3. HDP were associated with Corynebacterium amycolatum (p = 0.002) in T1 and Veillonella parvula (p = 0.028), Peptoniphilus sp HMSC062D09 (p = 0.047) and Peptostreptococcus anaerobius (p = 0.028) in T3. Only Peptoniphilus and Peptostreptococcus genera have previously demonstrated associations with PE.
Conclusion: Pregnancy complications such as GDM and HDP are associated with specific vaginal microbial species. The clinical significance of these associations requires further study. More research is needed to determine if early trimester screening methods of vaginal microbial signatures can predict the development of these complications later in the pregnancy to serve as targets for therapeutic intervention periconceptually.
Keywords
human vaginal microbiome, gestational diabetes mellitus, preeclampsia
References
1. Truong DT, Franzosa EA, Tickle TL, Scholz M, Weingart G, Pasolli E, et al. MetaPhlAn2 for enhanced metagenomic taxonomic profiling. Nature Methods. 2015;12(10):902-3.
2. R Core Team. R: A Language and Environment for Statistical Computing. Vienna, Austria: R Foundation for Statistical Computing; 2022.