Vaginal bacterial load in the second trimester is associated with early preterm birth recurrence: a nested case-control study



Goodfellow, Laura ORCID: 0000-0002-8111-5007, Verwijs, Marijn, Care, Angharad, Sharp, Andrew, Ivandic, Jelena, Poljak, Borna, Roberts, Devender, Bronowski, Christina, Gill, Christina, Darby, Alistair
et al (show 4 more authors) (2021) Vaginal bacterial load in the second trimester is associated with early preterm birth recurrence: a nested case-control study.

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Abstract

<h4>Objective</h4> To assess the association between vaginal microbiome (VMB) composition and recurrent early spontaneous preterm birth (sPTB)/preterm prelabour rupture of membranes (PPROM). <h4>Design</h4> Nested case-control study. <h4>Setting</h4> UK tertiary referral hospital. <h4>Sample</h4> High-risk women with previous sPTB/PPROM <34 +0 weeks gestation who had a recurrence (n=22) or delivered at ≥37 +0 weeks without PPROM (n=87). <h4>Methods</h4> Vaginal swabs collected between 15-22 weeks gestation were analysed by 16S rRNA gene sequencing and 16S quantitative PCR. <h4>Main outcome measure</h4> Recurrent early sPTB/PPROM. <h4>Results</h4> 28/109 high-risk women had anaerobic vaginal dysbiosis, with the remainder dominated by lactobacilli ( L. iners 36/109, L. crispatus 23/109, or other 22/109). VMB type, diversity, and stability were not associated with recurrence. Women with a recurrence, compared to those without, had a higher median vaginal bacterial load (8.64 vs. 7.89 log 10 cells/μl, adjusted odds ratio (aOR)=1.90, 95% confidence interval (CI)=1.01-3.56, p=0.047) and estimated Lactobacillus concentration (8.59 vs. 7.48 log 10 cells/μl, aOR=2.35, CI=1.20-4.61, p=0.013). A higher recurrence risk was associated with higher median bacterial loads for each VMB type after stratification, although statistical significance was reached only for L. iners -domination (aOR=3.44, CI=1.06-11.15, p=0.040). Women with anaerobic dysbiosis or L. iners -domination had a higher median vaginal bacterial load than women with a VMB dominated by L. crispatus or other lactobacilli (8.54, 7.96, 7.63, and 7.53 log 10 cells/μl, respectively). <h4>Conclusions</h4> Vaginal bacterial load is associated with early sPTB/PPROM recurrence. Domination by lactobacilli other than L. iners may protect women from developing high bacterial loads. Future PTB studies should quantify vaginal bacteria and yeasts. <h4>Funding</h4> Wellbeing of Women, London, UK <h4>Tweetable abstract</h4> Increased vaginal bacterial load in the second trimester may be associated with recurrent early spontaneous preterm birth.

Item Type: Article
Depositing User: Symplectic Admin
Date Deposited: 12 Feb 2021 14:31
Last Modified: 12 Aug 2022 07:11
DOI: 10.1101/2021.01.14.21249680
URI: https://livrepository.liverpool.ac.uk/id/eprint/3115563