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



Goodfellow, Laura, Verwijs, Marijn C, Care, Angharad, Sharp, Andrew, Ivandic, Jelena, Poljak, Borna, Roberts, Devender, Bronowski, Christina, Gill, A Christina, Darby, Alistair C
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

<jats:title>Abstract</jats:title><jats:sec><jats:title>Objective</jats:title><jats:p>To assess the association between vaginal microbiome (VMB) composition and recurrent early spontaneous preterm birth (sPTB)/preterm prelabour rupture of membranes (PPROM).</jats:p></jats:sec><jats:sec><jats:title>Design</jats:title><jats:p>Nested case-control study.</jats:p></jats:sec><jats:sec><jats:title>Setting</jats:title><jats:p>UK tertiary referral hospital.</jats:p></jats:sec><jats:sec><jats:title>Sample</jats:title><jats:p>High-risk women with previous sPTB/PPROM &lt;34<jats:sup>+0</jats:sup> weeks gestation who had a recurrence (n=22) or delivered at ≥37<jats:sup>+0</jats:sup> weeks without PPROM (n=87).</jats:p></jats:sec><jats:sec><jats:title>Methods</jats:title><jats:p>Vaginal swabs collected between 15-22 weeks gestation were analysed by 16S rRNA gene sequencing and 16S quantitative PCR.</jats:p></jats:sec><jats:sec><jats:title>Main outcome measure</jats:title><jats:p>Recurrent early sPTB/PPROM.</jats:p></jats:sec><jats:sec><jats:title>Results</jats:title><jats:p>28/109 high-risk women had anaerobic vaginal dysbiosis, with the remainder dominated by lactobacilli (<jats:italic>L. iners</jats:italic> 36/109, <jats:italic>L. crispatus</jats:italic> 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<jats:sub>10</jats:sub> cells/μl, adjusted odds ratio (aOR)=1.90, 95% confidence interval (CI)=1.01-3.56, p=0.047) and estimated <jats:italic>Lactobacillus</jats:italic> concentration (8.59 vs. 7.48 log<jats:sub>10</jats:sub> 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 <jats:italic>L. iners</jats:italic>-domination (aOR=3.44, CI=1.06-11.15, p=0.040). Women with anaerobic dysbiosis or <jats:italic>L. iners</jats:italic>-domination had a higher median vaginal bacterial load than women with a VMB dominated by <jats:italic>L. crispatus</jats:italic> or other lactobacilli (8.54, 7.96, 7.63, and 7.53 log<jats:sub>10</jats:sub> cells/μl, respectively).</jats:p></jats:sec><jats:sec><jats:title>Conclusions</jats:title><jats:p>Vaginal bacterial load is associated with early sPTB/PPROM recurrence. Domination by lactobacilli other than <jats:italic>L. iners</jats:italic> may protect women from developing high bacterial loads. Future PTB studies should quantify vaginal bacteria and yeasts.</jats:p></jats:sec><jats:sec><jats:title>Funding</jats:title><jats:p>Wellbeing of Women, London, UK</jats:p></jats:sec><jats:sec><jats:title>Tweetable abstract</jats:title><jats:p>Increased vaginal bacterial load in the second trimester may be associated with recurrent early spontaneous preterm birth.</jats:p></jats:sec>

Item Type: Article
Depositing User: Symplectic Admin
Date Deposited: 12 Feb 2021 14:31
Last Modified: 21 Oct 2021 07:10
DOI: 10.1101/2021.01.14.21249680
URI: https://livrepository.liverpool.ac.uk/id/eprint/3115563