Transfer of IVF-contaminated blastocysts with removal of the zona pellucida resulted in live births

Effects of Embryo Microbial Contamination on ART and Neonatal Outcomes

Purpose

This study investigated the incidence and microbial etiology of embryo contamination in assisted reproductive technology (ART), and its influence on embryo development, pregnancy and neonatal outcomes.

Methods

A retrospective analysis was conducted on embryo contamination at the Reproductive Centre of the Third Affiliated Hospital of Guangzhou Medical University, between 2018 and 2021.

Results

In the period from 2018 to 2021, the average incidence of embryo contamination was 0.12%. Bacterial growth was observed in 39 cases, with a preponderance of Escherichia coli (20, 51.28%), Streptococcus agalactiae (7, 17.95%). The fertilization rate of contaminated embryos was 18.18% (Klebsiella pneumoniae) to 94.79% (S. agalactiae), the cleavage rate was 9.09% (Enterobacter cloacae) to 98.90% (S. agalactiae), and the available embryo rate of Day 3 was 0 (Klebsiella pneumoniae, Enterobacter cloacae) to 63.33% (S. agalactiae). Blastocyst formation rate was 3.23% (Proteus mirabilis) to 64.29% (Streptococcus mitis). E. coli contamination occurred mostly on Day 1, and S. agalactiae on Days 3 and 5. After rinsing and rescuing treatment, six healthy male babies were born.

Conclusion

E. coli and S. agalactiae were the most common bacterial embryo contaminants. Most microbial contamination can significantly decrease the fertilization rate. Embryo transfer after rinsing and continuing culture had no negative effect on neonatal outcomes, but there was an increased risk of early abortion due to E. coli contamination.

Vertical transmission of microbiomes into embryo culture media and its association with assisted reproductive outcomes

RESEARCH QUESTION

Can microbes vertically transmit from semen and follicular fluid to embryo culture media during assisted reproductive technology (ART) treatment?

DESIGN

Spent embryo culture media (SECM), seminal fluid and follicular fluid samples were collected from 61 couples with infertility undergoing ART treatment at the Prince of Wales Hospital, Hong Kong SAR, China. Metagenomic analysis was conducted using 16s rRNA sequencing to identify the source of microbes in SECM, correlation between the semen microbiome and male infertility, and correlation between the follicular fluid microbiome and female infertility.

RESULTS

Microbial vertical transmission into SECM was reported in 82.5% of cases, and semen was the main source of contamination in conventional IVF cases. The increased abundances of Staphylococcus spp. and Streptococcus anginosus in semen had negative impacts on total motility and sperm count, respectively (P < 0.001). Significant increases in abundance of the genera Prophyromonas, Neisseria and Facklamia were observed in follicular fluid in women with anovulation, uterine factor infertility and unexplained infertility, respectively (P < 0.01). No significant correlation was found between the bacteria identified in all sample types and ART outcomes, including fertilization rate, embryo development, number of available embryos, and clinical pregnancy rate.

CONCLUSION

Embryo culture media can be contaminated during ART treatment, not only by seminal microbes but also by follicular fluid and other sources of microbes. Strong correlations were found between specific microbial taxa in semen and sperm quality, and between the follicular fluid microbiome and the aetiology of female infertility. However, no significant association was found between the microbiomes of SECM, semen and follicular fluid and ART outcomes.

Successful pregnancy with intracytoplasmic sperm injection after bacterial contamination of embryo culture in in vitro fertilization: a case report

BACKGROUND

Bacterial infection of embryo culture medium is rare but may be detrimental. The main source of embryo culture contamination is semen. Assisted reproduction centers currently lack consensus regarding the methods for preventing and managing embryo culture infection. In our recent case, a successful pregnancy was achieved with intracytoplasmic sperm injection after failed conventional in vitro fertilization owing to bacterial contamination.

CASE PRESENTATION

We present a case report of two consecutive in vitro fertilization-intracytoplasmic sperm injection cycles with photo and video documentation of the bacterial growth. A 36-year-old Hungarian woman and her 37-year-old Hungarian partner came to our department. They had two normal births followed by 2 years of infertility. The major causes of infertility were a closed fallopian tube and asthenozoospermia. Bacterial infection of the embryo culture medium was observed during in vitro fertilization and all oocytes degenerated. The source was found to be the semen. To prevent contamination, intracytoplasmic sperm injection was used for fertilization in the subsequent cycle. Intracytoplasmic bacterial proliferation was observed in one of the three fertilized eggs, but two good-quality embryos were successfully obtained. The transfer of one embryo resulted in a successful pregnancy and a healthy newborn was delivered.

CONCLUSION

Intracytoplasmic sperm injection may be offered to couples who fail conventional in vitro fertilization treatment owing to bacteriospermia, as it seems to prevent infection of the embryo culture. Even if bacterial contamination appears, our case encourages us to continue treatment. Nevertheless, the development of new management guidelines for the prevention and management of bacterial contamination is essential.

Zona pellucida removal resulted in a successful live birth: Report on a case with recurrent implantation failure due to embryonic bacteria contamination

Key clinical message

In in vitro fertilization (IVF), laser offers several advantages. In this study, we employed laser to eliminate the zona pellucida of a contaminated embryo. This approach helps to rescue embryo with bacterial contamination, and improve embryo-endometrium interaction.

Abstract

To present a case report on the removal of a contaminated zona pellucida from an embryo of patient with a history of recurrent implantation failure (RIF), which was followed by a successful live birth. We present the case of a 34-year-old patient with a history of 3 years of infertility who underwent in vitro fertilization. During the culture process, the embryos became contaminated, leading to three failed implantations. Despite the aneuploidy of the embryo and the implementation of a washing technique, the contamination persisted. In the final attempt, the contaminated zona pellucida was successfully removed using laser, followed by embryo transfer, resulting in a live birth. We provided detailed clinical information, including patient demographics, infertility history, ovarian response, evidence of bacterial contamination, embryo development, treatment protocols, and outcomes. Laser excision of the zona pellucida is a safe and effective method for addressing bacterial infection in embryos.

Analysis of the clinical outcomes of microbial contamination caused by environmental contamination of the embryology laboratory during IVF-ET treatment cycles

BACKGROUND

Bacterial contamination may cause loss of or damage to cultured oocytes or embryos, resulting in the lack of transplantable embryos during IVF embryo culture. However, there are few reports about IVF embryo contamination caused by embryology laboratories. In this work, we evaluated clinical pregnancy outcomes and the risk of maternal and infant complications after embryo contamination caused by environmental pollution during IVF.

METHODS

The authors retrospectively analyzed 2490 IVF-ET ovulation induction therapy cycles in the Reproductive Center of Yichang Central People's Hospital from January 2015 to May 2022. According to the presence or absence of embryo culture medium contamination, the two groups were divided into an embryo contamination cycle and a nonembryo contamination cycle. The primary outcome parameters were the characteristics and progress of embryo culture medium contamination. Embryo laboratory outcomes, pregnancy outcomes, and maternal and infant complications were secondary outcome parameters.

RESULTS

One case of embryo contamination originated from semen contamination. The remaining 15 cases involved environmental contamination outbreaks in embryo culture chambers, caused by Staphylococcus pasteuri. Compared with conventional uncontaminated IVF cycles, the 15 cases of contaminated embryo cycles showed no significant difference in embryo laboratory outcomes, pregnancy outcomes, or maternal and infant complications except for a slightly higher rate of fetal growth retardation. Ultimately, 11 live-born infants were successfully delivered, of which 2 were premature. The remaining 4 patients did not become pregnant after 1-2 transfers due to a lack of transferable embryos.

CONCLUSION

When the embryo culture medium is contaminated due to the environmental contamination of the IVF culture room, it is feasible to perform daily rapid rinsing of the culture medium and avoid blastocyst culture as remedial treatment. However, the long-term impact on offspring needs further prospective research.

Bacteriospermia - A formidable player in male subfertility

Bacterial colonization of male reproductive tissues, cells, and fluids, and the subsequent impact of bacteria on the sperm architecture, activity, and fertilizing potential, has recently gained increased attention from the medical and scientific community. Current evidence strongly emphasizes the fact that the presence of bacteria in semen may have dire consequences on the resulting male fertility. Nevertheless, the molecular basis underlying bacteriospermia-associated suboptimal semen quality is sophisticated, multifactorial, and still needs further understanding. Bacterial adhesion and subsequent sperm agglutination and immobilization represent the most direct pathway of sperm-bacterial interactions. Furthermore, the release of bacterial toxins and leukocytic infiltration, associated with a massive outburst of reactive oxygen species, have been repeatedly associated with sperm dysfunction in bacteria-infested semen. This review serves as a summary of the present knowledge on bacteriospermia-associated male subfertility. Furthermore, we strived to outline the currently available methods for assessing bacterial profiles in semen and to outline the most promising strategies for the prevention and/or management of bacteriospermia in practice.

A new method to rescue embryos contaminated by bacteria

Objective

To report a case of successful pregnancy involving embryos that wereaffected by bacterial contamination.

Design

A case report.

Setting

Academic assisted reproductive center.

Patient(s)

A 31-year–old infertile patient with obstructed fallopian tubes facing bacterial contamination in her embryos during in vitro fertilization.

Intervention(s)

The zona pellucida (ZP) of the embryos that was contaminated by bacteria was removed by acidic Tyrode’s solution. The ZP-free embryos were then cultured in a time-lapse culture dish with 1 zygote per well until day 5 when a single ZP-free blastocyst was selected for transfer.

Main Outcome Measure(s)

The rate of obtaining embryos without recurrence of bacterial contamination and the developmental potential of the embryos.

Result(s)

Twenty oocytes were retrieved and were coincubated with sperm in vitro overnight. A total of 9 zygotes with 2 pronuclei and 3 zygotes with 1 pronucleus were obtained. Unfortunately, all zygotes were contaminated by the Klebsiella pneumoniae bacteria. The ZP of 7 zygotes were removed using acidic Tyrode’s solution (ZP-free group), whereas the remaining 5 zygotes and 3 metaphase II (MII) stage oocytes were washed with G-1 PLUS medium multiple times (washing treatment group). In the washing treatment group, all embryos experienced recontamination on day 2 and were dead by day 3. In the ZP-free group, 2 embryos were found to be recontaminated on day 2. The remaining 5 embryos that stayed uncontaminated were selected for blastocyst culture. On day 5, 2 of the cultured embryos developed into blastocysts. One blastocyst was transferred during the fresh cycle, and the other was vitrified. A single intrauterine gestation was confirmed 4 weeks after the transfer. At the time of writing this article, the patient was 30 weeks pregnant without any occurrence of intrauterine infection during pregnancy.

Conclusion(s)

Zona pellucida removal is a safe and effective method to rescue embryos contaminated with bacteria.

Contamination of ART culture Media-The role of semen and strategies for prevention

OBJECTIVE

Microbial contamination of ART culture media is rare but serious. We examined our own experience and conducted a review of the literature with a view to preventing its occurrence and recurrence.

CASE REPORT

A total of 12 cases were recorded during January 2006 to March 2019. The contaminations were caused by semen and were shown to be bacteria that were resistant to the prophylactic antibiotics used in the medium. After the procedures were cancelled due to contaminations, nine husbands received antibiotic treatment, while nine couples changed over to the ICSI program. Eventually, eight couples concluded the study with live birth deliveries, and there was no recurrence of contamination.

CONCLUSION

ART laboratories should preserve all sperm suspension samples until embryo transfer has been completed for the purpose of checking whether contamination has occurred. In addition to antibiotic treatment, implementation of the ICSI procedure during the next ART cycle has already been proven to be effective. In the future, the zona-removal technique may be considered as another potential option.

The complex microbiome from native semen to embryo culture environment in human in vitro fertilization procedure

BACKGROUND

Only a few microbial studies have conducted in IVF (in vitro fertilization), showing the high-variety bacterial contamination of IVF culture media to cause damage to or even loss of cultured oocytes and embryos. We aimed to determine the prevalence and counts of bacteria in IVF samples, and to associate them with clinical outcome.

METHODS

The studied samples from 50 infertile couples included: raw (n = 48), processed (n = 49) and incubated (n = 50) sperm samples, and IVF culture media (n = 50). The full microbiome was analyzed by 454 pyrosequencing and quantitative analysis by real-time quantitative PCR. Descriptive statistics, t-, Mann-Whitney tests and Spearman's correlation were used for comparison of studied groups.

RESULTS

The study involved normozoospermic men. Normal vaginal microbiota was present in 72.0% of female partners, while intermediate microbiota and bacterial vaginosis were diagnosed in 12.0 and 16.0%, respectively. The decreasing bacterial loads were found in raw (35.5%), processed (12.0%) and sperm samples used for oocyte insemination (4.0%), and in 8.0% of IVF culture media. The most abundant genera of bacteria in native semen and IVF culture media were Lactobacillus, while in other samples Alphaproteobacteria prevailed. Staphylococcus sp. was found only in semen from patients with inflammation. Phylum Bacteroidetes was in negative correlation with sperm motility and Alphaproteobacteria with high-quality IVF embryos.

CONCLUSION

Our study demonstrates that IVF does not occur in a sterile environment. The prevalent bacteria include classes Bacilli in raw semen and IVF culture media, Clostridia in processed and Bacteroidia in sperm samples used for insemination. The presence of Staphylococcus sp. and Alphaproteobacteria associated with clinical outcomes, like sperm and embryo quality.

Microbial contamination in assisted reproductive technology: source, prevalence, and cost

Even the strictest laboratories and clinics are prone to the occurrence of microbial contamination. In the case of in vitro fertilization (IVF) research and practice facilities, the number of possible sources is particularly vast. In addition to ambient air, personnel, and non-sterilized materials, follicular fluid and semen from patients are a very common gateway for a diverse range of bacteria and fungi into embryo cultures. Even so, reports of contamination cases are rare, what leads many clinics to see the issue as a negligible risk. Microbiological contamination may result in the demise of the patient's embryos, leading to additional costs to both the patient and the clinics. Regardless of financial loss, emotional costs, and stress levels during IVF are highly distressing. Other worrisome consequences include DNA fragmentation, poor-quality embryos, early pregnancy loss or preterm birth, and possible long-term damages that need further investigation. In this review, we aimed to shed a light on the issue that we consider largely underestimated and to be the underlying cause of poor IVF outcomes in many cases. We also discuss the composition of the microbiome and how its interaction with the reproductive tract of IVF-seeking patients might influence their outcomes. In conclusion, we urge clinics to more rigorously identify, register, and report contamination occurrences, and highlight the role of the study of the microbiome to improve overall results and safety of assisted reproduction.