Influence of Vaginal and Endometrial Microbiome on the Results of Assisted Reproduction Techniques and Probiotic Administration Effect: Controlled Before-and-after Study

This study will be performed after the observational study "Vaginal microbiome influence on the results of assisted reproduction techniques". The main goal of this previous study will be to identify patterns of vaginal and / or endometrial microbiome in relation to the gestation rate in women with implantation failure and / or repeat abortions who undergo an oocyte donation treatment. The vaginal and endometrial microbiome of women with (i) implantation failure, (ii) repeat abortions and (iii) control group without implantation failure or repeat abortions, will be analyzed before and after the embryo transfer.

Those women who do not achieve pregnancy will be eligible for the present study. The objective of the present study to analyze the vaginal microbiome in patients who have not achieved gestation after oocyte donation treatment and after probiotic administration.

All patients will receive vaginal probiotic according to the standard regimen: 1 tablet (via vaginal) for 5 days after menstruation during the same cycle of the next embryo transfer.

The vaginal sample will be analyzed after taking the probiotic. Sample collection will be performed the embryo transfer day and on the day of the pregnancy test. Follow up of gestation will be carried out.

Vaginal sample collection: obtention of vaginal fluid with vaginal swab by direct visualization. Direct visualization means having the patient in a lithotomy position, like a routine gynecological examination by visualization with a vaginal speculum.