On this basis, the authors suggest that it may be advisable to postpone fertility treatment in patients with ‘unfavorable’ vaginal microbiota until a normal balance is achieved.
Principal investigator Ida Engberg Jepsen from the Fertility Clinic at the University Hospital of Zealand, Denmark, will present the findings today at ESHRE’s 38th Annual Meeting. She said the ‘spontaneous’ improvement rates observed in the patients could provide the basis for a change in approach to timing IVF.
‘However, rates of spontaneous improvement over a period of one to three months may provide the basis for an alternative treatment. This strategy would involve postponing fertility treatment until spontaneous improvement occurs, but further research is still needed. The specific vaginal probiotics tested in this study did not affect the predisposition of the vaginal microbiota prior to IVF. But probiotics in general have yet to be discounted. ‘
In contrast, people with an imbalance – or a biological disorder – where lactobacillus levels are too low may have a lower chance of implantation of the embryo in the uterus.
The study was conducted at a university fertility clinic from April 2019 to February 2021. A total of 74 women referred to IVF treatment were recruited. All had abnormal lactobacillus profiles, varying from low to moderate quality.
The women were randomly assigned to receive a vaginal probiotic capsule (n = 38) or a placebo (n = 36). Samples were taken to determine the effect on vaginal microbiota 10 days after taking probiotics and again during the next menstrual cycle (on days 21 to 25 of the cycle). Improvement in vaginal microbiota was defined as a change in receptivity from low to moderate; from low to high; and medium to high.
The results showed that the vaginal microbiome was improved by 40% in the placebo group and 29% in those taking the lactobacillus probiotic. This does not represent a significant difference. Similar results were observed in the menstrual cycle after the intervention.
The authors recommend that only two strains of lactobacilli be contained in the probiotic samples. In addition, they say that a broad classification of the vaginal microbiome profile may not capture ‘more subtle changes’ that could affect fertility.
The study was part of The ReproHealth Research Consortium Zealand University Hospital.