IVF or IVF-ICSI (intracytoplasmic sperm injection)achieve live birth rates ranging between 25-35% per cycle. There are so many factors that go into whether or not the embryo transfer is going to take, and even more factors coming into play if the pregnancy is going to result in a live birth.
A prospective study was done assessing one of the factors that may play a role in the success of IVF – the composition of the vaginal microbiome. The study evaluated the different compositions of the vaginal microbiome in women undergoing IVF and then assessed the implantation rates of their IVF cycle.
The study found that women with a lower percentage of lactobacillus bacteria as a part of their vaginal microbiome were less likely to have successful embryo implantation. The study found that women who had favorable lactobacillus species in their vaginal microbiome but had <60% composition of lactobacillus crispatushad a higher chance of pregnancy.
This study opens up conversation around the role the vaginal microbiome may play in embryo implantation and pregnancy – however this study is only looking at implantation with respect to ART, not non-ART pregnancies. As well, this study is only looking at successful implantation, not necessarily pregnancy outcomes after implantation.
It is neat to think though, that if more research is to come out on the vaginal microbiome and its correlation to pregnancy outcomes, clinically that is something we can manipulate via healthy diet, probiotic supplementations and vaginal hygiene. If more solid research is to come out on this topic and we have the ability to clinically control one of the many factors that goes into implantation rates, that would be amazing!