The Importance of a Healthy Vaginal Microbiome

Vaginal Microbiome testing is gathering rather a lot of attention in the reproductive medicine field and for all the right reasons! The latest research shows that a healthy microbiota is essential for implantation success and a healthy ongoing pregnancy. Yet it’s unlikely you’ll hear your UK IVF consultant offering you such a test.

Once again I’m afraid we’re behind the times when it comes to relevant diagnostics before embarking on your IVF cycles. But clinics abroad are now running these tests as standard due to the overwhelming evidence supporting their use in aiding a healthy microbiome prior to planning a pregnancy. 

As you know, we always aim to remain ahead of the curve so that we may bridge the gap between the diagnostics patients are offered abroad and those that they are afforded here. So, we’ve been offering vaginal microbiome tests for several months now and we’ve seen some pretty remarkable things. So much so that we are now recommending these tests as standard to all our patients. Let me tell you about it…

A study from October 2023 analysed the evidence to date and what it confirmed is that, basically, vaginas and babies alike love Lactobacillus. It likes all the flavours - gasseri, iners, jensenii - but the one it likes the most when it comes to cooking up a baby is crispatus.

“Non-Lactobacillus-dominated vaginal microbiota has been associated with poor gynecologic health and complications during pregnancy. Lactobacilli and especially Lactobacillus crispatus associate with good reproductive health and dominate the microbiota during healthy pregnancy.” (Väinämö, 2023)

L. crispatus has been shown to be so fundamentally important for a healthy pregnancy that some scientists in the field of reproductive medicine (Koedooder et al) developed an algorithm to predict the success of a woman’s first IVF/Embryo Transfer based on the relative abundance of L. crispatus prior to transfer. (Väinämö, 2023)

“L. crispatus was the most abundant species in the vaginal samples of women who achieved clinical pregnancy and live birth, compared to women with no pregnancy or live births (43.3% vs 23.1%, q = 0.017).” “And of the healthy pregnancies. L. crispatus (76.2%) dominated all early pregnancy samples.” (Väinämö, 2023)

Ok, so I think we get it… L. crispatus is a big frickin deal in the fertility game. But what about the other guys? 

There are various other types of bacteria that have been shown to negatively affect implantation and pregnancy outcome. The key players are those associated with bacterial vaginosis (Prevotella bivia, garnderella vaginalis, atopobium vaginae), Strep B and E. Coli. 

“In the non-pregnancy group, P. bivia and Streptococcus anginosus were more prevalent and abundant” (Väinämö, 2023)

“Ralph et al. indicated when BV is identified before 16 weeks of gestation, the highest rates of preterm labor was detected, and BV was responsible for twofold risk of miscarriage in the first trimester. Similar to these results, Ugwumadu et al. found threefold increase in the risk of miscarriage in the first trimester.” (Işik et al, 2016)

E. Coli in pregnancy can be responsible for preterm rupture of the membranes (waters breaking), preterm delivery, or stillbirth in severe cases. It can also cause a low birth weight (weighing less than 5 pounds, 8 ounces) and sepsis in pregnancy. (NIH, 2023)

Therefore we feel it’s incredibly important that our patients take us up on our recommendation of vaginal microbiome testing and we are now offering this as standard, regardless of whether you may have symptoms of BV or otherwise. We are certainly seeing from the women we have tested that there are a good number of patients showing to have a high prevalence of bacterias associated with BV but who are asymptomatic (not showing symptoms). 

Another important point to mention is that some of these bacterias are considered sexually transmissible and therefore we can assume your partner is also infected and so the bacteria is happily passing between you. This is why it is important that both couples are treated at the same time and barrier method contraception is used prior to and during treatment.
 
And it’s not just female fertility that is affected by certain bacteria. Women with a high prevalence of ureaplasma or mycoplasma will be passing this bacteria to their partners. 

“Ureaplasma spp. has been identified as an etiology of male infertility since 1967. Friberg and Gnarpe demonstrated a higher frequency of Ureaplasma spp. isolated from the semen of men with unexplained infertility (76%) compared with fertile men (19%). Since then the relationship between Ureaplasma spp. infection and male infertility has been studied widely.”

So what is the treatment? A simple course of antibiotics. 

Now, we all know that antibiotics are not to be handed out like sweets. But if we know that treating bacterial infections has such a massive impact on our ability to conceive and carry a pregnancy to full term then it is obviously important we have access to these potentially life giving medications. 

For the main part your GP should be happy to assist you if have evidence of a bacterial infection. We also have our GP/quick prescribe service via The Thyroid Clinic that our patients can access should they feel in a hurry to start their course of antibiotics. 

We then ensure that women are given targeted probiotics that are rich in that all important L. crispatus to repopulate the vaginal microbiota with the types of bacteria they need for a healthy pregnancy…
​
Et Voila! (To honour all those delicious Latin words.)


S Väinämö, 2023, Longitudinal analysis of vaginal microbiota during IVF fresh embryo transfer and in early pregnancy [https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10715154/]


G Işık et al, 2016, Bacterial vaginosis in association with spontaneous abortion and recurrent pregnancy losses [https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4995870/]


NIH National Library of Medicine, April 2023, Escherichia coli (E. coli) [https://www.ncbi.nlm.nih.gov/books/NBK582525/]


Y Heng Zhou et al, December 2018, Journal of Microbiology, Immunology and Infection [https://www.sciencedirect.com/science/article/pii/S1684118217300713] 

---