Intravaginal probiotics before embryo transfer do not improve pregnancy rates in recurrent implantation failure cases: An RCT.

Background: Considering the considerable influence of the vaginal microbiome on endometrial receptivity and embryo implantation, we hypothesized that cases of recurrent implantation failure (RIF) might benefit from the intravaginal probiotic administration. Objective: Evaluation of the effects of intravaginal probiotic administration before frozen embryo transfer (FET) on the rates of pregnancy and the status of vaginal lactobacillary flora in cases of RIF. Materials and Methods: This was a randomized, parallel-group, clinical trial conducted at an infertility clinic in Tehran, Iran between January 2021 and September 2022. A total of 166 reproductive-aged women with a history of unexplained RIF were randomly assigned to either the probiotic group or the control group (n = 83/each group). The probiotic group received intravaginal probiotics (LactoVagⓇ) daily for 2 wk from the second day of the menstrual cycle along with the routine treatment of FET. The control group received only the routine treatment of FET. The primary outcome was the chemical pregnancy rate, and the secondary outcomes were the clinical pregnancy rate and the status of vaginal lactobacillary flora. Results: A total of 163 participants were included in the final analysis. The probiotic group had a slightly higher chemical pregnancy rate than the control group (39.02% vs. 33.33%), but the difference was not statistically significant (risk ratio: 1.71, 95% CI: 0.77-1.76; p = 0.449). The clinical pregnancy rate was also non-significantly higher in the probiotic group than the control group (37.80% vs. 33.33%; RR: 1.14, 95% CI: 0.76-1.74; p = 0.623). Conclusion: Intravaginal probiotic administration did not significantly improve the pregnancy rates in RIF cases undergoing FET. Further studies are needed to explore the optimal dose, duration, and timing of probiotic administration, as well as the mechanisms of action and the potential adverse effects of probiotics on the vaginal microbiome and the implantation process.

Comparing reactive oxygen species and DNA fragmentation in semen samples of unexplained infertile and healthy fertile men.

BACKGROUND: Male factor infertility has increased to more than 40% during the last decade. About 30% of these couples are diagnosed with unexplained infertility. In fact, reactive oxygen species (ROS), especially superoxide anion (O2-·) and hydrogen peroxide (H2O2), play a crucial role in regulation of physiological and pathological processes in spermatozoa. Moreover, since the diagnosis of unexplained infertility just through semen analysis is a matter of much controversy; we aimed to evaluate the levels of ROS and sperm DNA fragmentation in the semen samples of unexplained infertile and fertile control couples. METHODS: The semen samples of 28 unexplained infertile couples and 30 fertile control couples were analyzed according to WHO criteria. The intracellular levels of H2O2 and O2-· were detected by flow cytometry with 2',7'-Dichlorodihydrofluorescin diacetate and Dihydroethidium, respectively, and DNA fragmentation was evaluated by sperm chromatin dispersion test. RESULTS: In unexplained infertile group, sperm motility and normal morphology were significantly lower than the control. The levels of sperm H2O2, O2-·, and DNA fragmentation were significantly higher in unexplained infertile men compared to fertile. Moreover, a positive correlation was found between the level of H2O2 and sperm DNA fragmentation in the unexplained infertile group. Besides, reduced sperm motility in the unexplained infertile group was significantly correlated with elevated levels of ROS. CONCLUSIONS: The higher levels of intracellular ROS and DNA fragmentation in the semen samples of unexplained infertile couples and their causes might be considered as an important factor related to diagnosis and treatment of the unexplained infertile couples.