Predicting Premature Birth With Vaginal Microbiome Testing

Nicky Broyd

August 24, 2021

The risk of premature birth could be predicted as early as week 10 of pregnancy by testing the vaginal microbiome, according to King's College London research.

The study, published in the Journal of Clinical Investigation JCI Insight, builds on previous research linking spontaneous preterm birth with infection and inflammation shortening and weakening the cervix.

Cervicovaginal Samples

Cervicovaginal samples were studied from 346 mothers at four UK hospitals, including 60 who gave birth prematurely.

Samples were taken at 10-15 weeks and 16-23 weeks, before being grouped by bacterial and biochemical analysis.

These data were cross referenced with cervical length measurement, the current standard premature birth risk assessment method.

The study found a combination of Lactobacillus crispatus, L. acidophilus, glucose, aspartate, and calcium was linked to birth at or before 34 weeks

The metabolites leucine, tyrosine, aspartate, lactate, betaine, acetate, and calcium were associated with birth at or before 37 weeks.

The study also found ethnicity differences in samples, but the authors say these were not significant enough to explain higher rates of premature birth in Black women and larger studies are needed in this area. 

Managing Risks

Study author, Professor Andrew Shennan, King's College London, who runs the Tommy's charity Preterm Birth Surveillance Clinic at St Thomas' Hospital, said in a news release: "Premature birth is very hard to predict, so doctors have to err on the side of caution and mothers deemed to be at risk often don't actually have their babies early, putting undue strain on everyone involved.

"My team has developed preterm birth prediction tools that are very accurate later in pregnancy, like foetal fibronectin tests – but at that stage, you can only manage the risks, not stop it from happening. The sooner we can find out who's at risk, the more we can do to keep mothers and babies safe."

Lead academic on the ongoing INSIGHT study, Rachel Tribe, professor of maternal and perinatal sciences at King's College, added: "With so many factors in play, it's unlikely that testing for the same single bacteria species will predict premature birth in every mother, but we now have a panel of bacteria and metabolites that could be useful. In particular, tests during early pregnancy for Lactobacillus crispatus and L. acidophilus could provide reassurance to mothers who would otherwise be unduly worried, and help those who need it get specialist care as soon as possible. After 5 years of work on this study, we're delighted to have this greater understanding of how the vaginal environment can influence preterm birth risk."

Exciting Potential

Funding and support for the research included charities Tommy's and the Rosetrees Trust, along with the National Institute for Health Research, and the Wellcome Trust.

Tommy's Chief Executive, Jane Brewin, said: "With 60,000 babies born prematurely each year in the UK, there's a real and urgent need for better ways to predict and prevent preterm birth. This new study has not only uncovered warning signs that could be used to develop new tests, but also a possible treatment which could make pregnancy safer for the most vulnerable, so this new avenue of research has really exciting potential for clinical practice."

Citation Information: JCI Insight. 2021;6(16):e149257.


Comments on Medscape are moderated and should be professional in tone and on topic. You must declare any conflicts of interest related to your comments and responses. Please see our Commenting Guide for further information. We reserve the right to remove posts at our sole discretion.
Post as: