Does bacterial colonization during embryo transfer have an impact on pregnancy rate in ICSI? : Tunisian preliminary results

Vaginal dysbiosis - the association with reproductive outcomes in IVF patients: a systematic review and meta-analysis

PURPOSE OF REVIEW

To examine impact of vaginal dysbiosis (VD), including bacterial vaginosis (BV) and aerobic vaginitis (AV) on reproductive outcomes of in vitro fertilization (IVF) patients.

RECENT FINDINGS

BV-bacteria (e.g. Gardnerella ) and AV-bacteria (e.g. Streptococci and Enterococci ) have been identified in the endometrium. However, there is inconclusive evidence whether IVF patients with VD have lower success rates.

SUMMARY

The present systematic review and meta-analysis of PubMed/Medline, until December 2023 included 25 studies, involving 6835 IVF patients. Overall VD was defined as an approximation of community state type IV, including BV and AV-type dysbiosis based on either molecular or microscopy methods. Outcomes were live birth rate (LBR), early pregnancy loss (EPL), clinical pregnancy rate (CPR), and biochemical pregnancy rate (BPR).Vaginal dysbiosis prevalence was 19% [1271/6835, 95% confidence interval (CI) 18-20%]. Six studies examined AV-type dysbiosis with a prevalence of 4% (26/628, 95% CI 3-6%). Vaginal dysbiosis correlates with a higher EPL [relative risk (RR) = 1.49, 95% CI 1.15-1.94] and lower CPR (RR = 0.82, 95% CI 0.70-0.95). No statistically significant impact of VD, BV, or AV was found on LBR and BPR.Thus, the association between VD and reproductive outcome remains puzzling as it is difficult to explain how VD impacts CPR and EPL but not LBR and BPR.

The relationship between microbial contaminations of embryo transfer catheters with pregnancy outcome after embryo transfer

Background

Different stages of assisted reproductive technologies are susceptible to contamination by various microorganisms.

Objective

The aim of the study was to investigate the relationship between microbial contamination of embryo transfer catheters and the pregnancy outcome after embryo transfer.

Methods

This cohort study was conducted on 60 patients candied for in vitro fertilization and embryo transfer cycles from 2021 to 2022. All embryos were transferred using a sterile syringe. The catheter contamination was checked by the microbial culture method, and in the case of microbial culture that were negative, polymerase chain reaction was done to confirm the result. The data analyzed using STATA 17 to determine the impact of catheter contamination on the clinical pregnancy rate.

Results

The average age of peoples whose microbial culture was positive was lower than that of people whose microbial culture was negative (P<0.05). Also the results showed that people who live in villages have more positive microbial cultures than people who live in cities (P<0.05). Also there is no difference between the number of successful implantations and the pregnancy outcome between people whose microbial culture results were positive or negative.

Conclusion

The results of the current study showed that the contamination of the embryo transfer catheter with microorganisms under our investigation did not affect the pregnancy outcome.

The effects of microbiota on reproductive health: A review

Reproductive issues are becoming an increasing global problem. There is increasing interest in the relationship between microbiota and reproductive health. Stable microbiota communities exist in the gut, reproductive tract, uterus, testes, and semen. Various effects (e.g., epigenetic modifications, nervous system, metabolism) of dysbiosis in the microbiota can impair gamete quality; interfere with zygote formation, embryo implantation, and embryo development; and increase disease susceptibility, thus adversely impacting reproductive capacity and pregnancy. The maintenance of a healthy microbiota can protect the host from pathogens, increase reproductive potential, and reduce the rates of adverse pregnancy outcomes. In conclusion, this review discusses microbiota in the male and female reproductive systems of multiple animal species. It explores the effects and mechanisms of microbiota on reproduction, factors that influence microbiota composition, and applications of microbiota in reproductive disorder treatment and detection. The findings support novel approaches for managing reproductive diseases through microbiota improvement and monitoring. In addition, it will stimulate further systematic explorations of microbiota-mediated effects on reproduction.

The effect of endocervical and catheter bacterial colonisation during in vitro fertilisation and embryo transfer (IVF-ET) on IVF success rate among asymptomatic women: a longitudinal prospective study

The adverse effects of bacterial contamination during in vitro fertilisation and embryo transfer (IVF-ET) have been studied previously. However, data on asymptomatic women with positive bacterial culture and their IVF outcome are lacking. This prospective longitudinal study was conducted on 74 women undergoing IVF-ET, of whom specimens from the endocervix and ET catheter were taken and sent to a laboratory for microbiological assessment. Then, patients were followed up for evaluation of chemical pregnancy (β-HCG > 25 mIU/mL) and clinical pregnancy (detected foetal heartbeat). The findings revealed that there was no significant difference in terms of biochemical (35.4% vs. 19.2%, p= .116) and clinical pregnancy rate (25.0% vs. 15.4%, p= .257) among ET catheter culture positive and negative women. This finding allows us to conclude that the positive culture in the absence of clinical signs of infection may not increase the risk of implantation failure.Impact StatementWhat is already known on this subject? There is growing evidence indicating that endometritis may decrease the endometrial receptiveness in in vitro fertilisation (IVF) cycles; however, there is a paucity of knowledge regarding IVF outcomes when the bacterial culture of embryo transfer (ET) catheter is positive.What the results of this study add? The present study demonstrates that positive ET catheter culture in asymptomatic women does not increase the risk of IVF failure.What the implications are of these findings for clinical practice and/or further research? Positive-culture, per se, may not be associated with poor IVF outcomes and further studies should be undertaken on this topic in various clinical settings using different protocols.

Withholding antibiotics does not reduce clinical pregnancy outcomes of natural cycle frozen embryo transfers

OBJECTIVE

To assess the impact of withholding doxycycline on the success rate of natural cycle frozen embryo transfers (NC-FET).

DESIGN

Retrospective cohort study.

SETTING

Single academic institution.

PATIENT(S)

Women undergoing 250 NC-FET with euploid blastocysts performed by a single provider.

INTERVENTION(S)

One hundred and twenty-five NC-FET cycles performed after January 2019 without antibiotic administration compared with 125 NC-FET cycles before January 2019 with doxycycline administration.

MAIN OUTCOME MEASURE(S)

Primary outcome: live birth (LB) or ongoing pregnancy rate (OPR, defined as pregnancies ≥13 weeks); secondary outcomes included positive β-human chorionic gonadotropin (β-hCG) level and clinical pregnancy rate (CPR, defined as the presence of fetal cardiac activity on ultrasound).

RESULT(S)

Each group of women comprised 125 NC-FET during the study period of March 2017 to March 2020. The women's mean age was 36.3 years and mean body mass index was 24 kg/m². Between the two groups, the baseline characteristics were similar, including age, body mass index, race, smoking status, parity, endometrial thickness, Society of Assisted Reproductive Technology diagnosis, and number of prior failed transfers. Comparing NC-FET with doxycycline administration versus without, we found no statistically significant difference in LB-OPR (64% vs. 62.6%), positive β-hCG (72.8% vs. 74.0%), or CPR (68% vs. 65.9%). After controlling for all variables in a logistic regression, doxycycline still had no effect on LB-OPR.

CONCLUSION(S)

In this analysis of similar patients undergoing NC-FET by a single provider, withholding doxycycline does not reduce success rates. Given the risks of antibiotics, our findings support withholding their use in NC-FET.