Wet Mount Microscopy of the Vaginal Milieu Does Not Predict the Outcome of Fertility Treatments: A Cross-sectional Study.

Abstract

The aim of the study was to evaluate whether vaginal dysbiosis (bacterial vaginosis [BV] or moderate/severe aerobic vaginitis [AV]/desquamative inflammatory vaginitis) in women subjected to intrauterine insemination (IUI) or in vitro fertilization/intracytoplasmic sperm injection influences the rates of pregnancy. This is a cross-sectional study involving 392 women who underwent IUI or in vitro fertilization/intracytoplasmic sperm injection at a fertility clinic. All had a slide collected for phase contrast wet mount microscopy (WMM), which was classified according to the International Society for the Study of Vulvovaginal Disease recommendations. Correlation between flora patterns and the rate of pregnancy were evaluated. There were no differences in any of the groups in terms of pregnancy rate (biochemical, clinical, at first trimester ultrasound, or live birth) after stratifying for the presence of BV, moderate or severe (ms) AV, BV and/or moderate or severe AV, cytolysis, or abnormal vaginal flora (lactobacillary grade ≥ IIb). The presence of Candida species, cocci, or bacilli morphotypes other than lactobacilli also showed no differences. The vaginal flora assessment by WMM at the time of IUI or oocyte retrieval was not predictive of the success of fertility treatments.The absence of differences may be due to intrinsic limitations of WMM (i.e., identifying only bacterial morphotypes), a positive impact of the treatments in the vaginal flora or because the sperm and embryo transfer is made directly into the uterine cavity, thus overcoming any cervical or vaginal dysbiosis disadvantage. Future studies should focus on the endometrial milieu, rather than in the vaginal and/or cervical one.