The effect of normalizing vaginal microbiome using Lactovag in improving pregnancy outcomes in frozen embryo transfer cycles: a randomized clinical trial.

Introduction: Successful frozen-thawed embryo transfer (FTET) depends on multiple factors among which the woman's vaginal microbiota has recently been considered important. Using probiotic products, such as Lactovag in infertile women, the vaginal microbiome can become close to the healthy status.

Objectives: The aim of this study was to evaluate the effect of Lactovag on normalizing vaginal microbiome, as well as its role in improving pregnancy outcomes in FTET cycles.

Patients And Methods: This randomized blinded clinical trial was conducted on 103 patients undergoing Assisted Reproductive Technology (ART) treatment at a tertiary university-based hospital between January and August of 2019. In the experiment group, the vaginal suppository Lactavag was prescribed, whereas in the control group, patients did not receive any microbiome supplements. Then, the pregnancy rate was compared in the two groups.

Results: There were no significant differences in baseline characteristics between the two study groups (p > 0.05). Positive B hCG was present in 28% (n = 26) of women, clinical pregnancy was achieved in 23.4% (n = 22) of them and fetal heart rate was detected in 21.3% (n = 20). These proportions were higher in the Lactovag group, although these differences were not significant (p > 0.05). Results showed that although transferring fetuses with grade A increased the odds of pregnancy with 1.53 (p = 0.001) folds, this ratio would be improved using Lactovag;1.68 (P value = 0.008).

Conclusions: It seems that the vaginal microbiota critically interplays with women's health and reproduction. A probiotic agent such as Lactovag can be useful in normalizing this environment and improving pregnancy outcomes in infertile women.