Association of clinical embryologists - guidelines on good practice in clinical embryology laboratories 2012

Value of estrogen pretreatment in patients with diminished ovarian reserve and elevated FSH on a line antagonist regimen: a retrospective controlled study

BACKGROUND

The key to enhancing the efficacy of antagonistic regimens in pregnancy is to better synchronize follicular growth during cycles of controlled ovarian stimulation (COS), especially in patients with diminished ovarian reserve (DOR). During in vitro fertilization-embryo transfer (IVF-ET) treatment, luteal phase estrogen pretreatment may enhance follicular development synchronization and yield of mature oocytes. However, the effect of estrogen pretreatment in DOR patients with elevated basal follicle-stimulating hormone (FSH) levels has not been well studied.

METHODS

We retrospectively analyzed the clinical data of patients with elevated basal FSH levels and DOR (401 cycles) who underwent IVF/intracytoplasmic monosperm injection (ICSI)-assisted conception. Both groups were treated with a flexible gonadotropin-releasing hormone (GnRH) antagonist regimen and were further divided into two groups according to whether they received luteal estrogen pretreatment. There were 79 patients in the estrogen pretreatment group and 322 patients in the control group. On the second day of the menstrual cycle, gonadotropin (Gn) stimulation of the ovaries was initiated. The general characteristics, clinical, biological parameters and outcomes of the two groups were compared.

RESULTS

The basic profiles of the two groups were similar (P > 0.05). More patients in the pretreatment group showed FSH rebound after gonadotropin (Gn) initiation, resulting in a significantly higher number of Gn days and total Gn than those in the control group (P < 0.05). There was no statistically significant difference in the number of days of antagonist use, follicle output rate (FORT), number of metaphase II(MII)eggs obtained, number of Two pronuclei (2PN) fertilized, number of D3 quality embryos, blastocyst formation rate, fresh embryo clinical pregnancy rate, cumulative pregnancy rate, and non-transferable embryo rate between the two groups (P > 0.05).

CONCLUSIONS

The use of luteal phase estrogen pretreatment in patients with elevated basal FSH combined with DOR resulted in high FSH levels after the release of negative feedback, which was detrimental to early follicular growth, did not increase the follicular output rate, may have increased the use and duration of controlled ovarian stimulation drugs, and did not increase the number of eggs gained or improve clinical outcomes.

ASEBIR Quality Special Interest Group guidance for quality in assisted reproduction technology

Assisted human reproduction has undergone rapid advances since its inception 45 years ago. To keep pace with these advances, assisted reproduction laboratories should adhere to a quality management system that addresses staffing and training, physical space and air quality, equipment maintenance and other operational matters, and ensures gamete and embryo handling in accordance with the latest quality and safety standards. Accordingly, this review aims to provide a reference document that highlights the critical aspects to consider when establishing and operating an ART laboratory. The review collates and expands upon published national and international guidelines and consensus documents, providing easier access to this large body of important information.

The paradox of the Italian clinical embryologist in the national public health system: hints towards harmonization of a postgraduate educational curriculum

Clinical embryologists are highly trained laboratory professionals with multiple roles, including laboratory, clinical, biobanking and quality system management. In most European countries, clinical embryologists are trained to work in Medically Assisted Reproduction (MAR) centres without a specifically dedicated educational path. The criteria required for employment vary according to the educational structure and the public or private nature of the centre. We have herein described the educational profile required by Italian clinical embryologists to work in MAR centres of the National Health System (NHS). Public centres currently represent 36% of all the Italian MAR clinics. According to the Italian law, a future clinical embryologist must achieve a 3-4 year unpaid post-graduate specialization in a different field, choosing from Genetics, Microbiology, Clinical Pathology or Nutrition. Accesses to the above-mentioned post-graduate courses are themselves very limited. Clinical embryologists are basically trained by senior colleagues. This situation makes inevitably difficult to recruit laboratory staff in NHS centres. Moreover, it represents an emblematic example of the need for an equal training curriculum, possibly ensuring a comparable education quality, mobility of trainees and dissemination of skills for clinical embryologists all over Europe.

The use of ICSI in ART: evidence for practice

This article reviews the evidence regarding the safety and efficacy of intra-cytoplasmic sperm injection (ICSI). It provides evidence-based clinical and laboratory guidelines and recommendations for use of ICSI within an assisted reproductive technology (ART) service. The guidelines address the evidence for the use of ICSI rather than conventional IVF (cIVF); the use of ART techniques supplementary to ICSI; and risks associated with ICSI. This article is not intended to be the only approved standard of practice or to dictate an exclusive course of treatment. Other plans of management may be appropriate, taking into account the needs and medical history of the patient, available resources, and institutional or clinical practice limitations.

Management of recurrent implantation failure: British Fertility Society policy and practice guideline

Recurrent implantation failure (RIF) is defined as the absence of a positive pregnancy test after three consecutive transfers of good quality embryos. There remains significant variation in clinical practice in the management of RIF. This British Fertility Society (BFS) Policy and Practice guideline analyses the evidence for investigations and therapies that are employed in RIF and provides recommendations for clinical practice and for further research. Evidence for investigations of sperm and egg quality, uterine and adnexal factors, immunological factors and thrombophilia, endocrine conditions and genetic factors and for associated therapies have been evaluated. This guideline has been devised to assist reproductive medicine specialists and patients in making shared decisions concerning management of RIF. Finally, suggestions for research towards improving understanding and management of RIF have also been provided.

Recalculating the staff required to run a modern assisted reproductive technology laboratory

STUDY QUESTION

What number of staff is sufficient to perform increasingly complicated processes in today's modern ART laboratories?

SUMMARY ANSWER

The adequate number of personnel required for the efficient and safe operation of modern ART laboratories needs to be calculated.

WHAT IS KNOWN ALREADY

In today's modern ART laboratories, the amount of time required to perform increasingly complicated processes has more than doubled, with a downward trend in the amount of work an embryologist can do. Different workload unit values have been used to evaluate each workload task and efficiency in a particular ART laboratory, as well as to occasionally compare one laboratory with another.

STUDY DESIGN, SIZE, DURATION

Seven senior embryologists working at different IVF centers, three public and four private centers, participated in this multicenter study conducted between 2019 and 2020. We prepared a survey to create a calculator for staff using the average (of three attempts) time spent in every laboratory by each embryologist of the center to perform any ART process.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Different laboratory processes and activities related to quality control, time spent and conventional human double witnessing were included in the survey. To calculate the number of processes that each embryologist can perform per year, an embryologist was considered to be having a full-time contract and working 7 or 8 h/day. The times included in the calculation of each task were those corresponding to the 95th percentile. For the calculations, Microsoft® Office Excel® Professional Plus 2019 was used.

MAIN RESULTS AND THE ROLE OF CHANCE

The survey showed that the time needed per embryologist to perform the different processes necessary for a classic IVF cycle without time lapse (TL) was 8.11 h, and with TL, it was 10.27 h. The calculated time also considered the time spent in documentation handling, cycle preparation, database management and conventional human double witnessing verification. An ICSI without TL needed 8.55 h, and with TL, it needed 10.71 h. An ICSI-PGT without a TL cycle needed 11.75 h, and with TL, it needed 13.91 h. Furthermore, 1.81 h should be added for every vitrification support needed. The time needed to control more than 200 critical steps, including equipment control and culture parameters, was 30 min per day plus 3.9 min per device to control.The time spent in semen analysis (including documentation handling, cycle preparation and database management) or intrauterine insemination with a partner sperm was 2.7 h. For donor sperm, an additional hour was required for the management involved. The time required to perform a testicular biopsy and cryopreserve the sample was 4 h. Similarly, the time required to perform seminal cryopreservation was 3.7 h.

LIMITATIONS, REASONS FOR CAUTION

The study was conducted considering a full-time contract embryologist working 7 or 8 h/day, 5 days a week, with days off according to the Spanish regulations. However, our findings can be adapted to foreign regulations using the developed online calculation platform.

WIDER IMPLICATIONS OF THE FINDINGS

A new advanced staff calculator allows any IVF laboratory to estimate the minimum number of embryologists necessary without compromising the security or success of the results. Nevertheless, we recommend a minimum of two qualified embryologists in every laboratory, regardless of the workload.

STUDY FUNDING/COMPETING INTEREST(S)

This work was funded by the Asociación para el Estudio de la Biología de la Reproducción (ASEBIR). None of the authors has any conflict of interest to declare.

TRIAL REGISTRATION NUMBER

N/A.

ISAR Consensus Guidelines on Safety and Ethical Practices in In vitro Fertilization Clinics

STUDY QUESTION

What are the Safe and Ethical practices for ART applicable in INDIA?

WHAT IS ALREADY KNOWN

The Indian IVF industry is booming; with mushrooming of assisted reproductive technology (ART) clinics in the country, the need for regulation is immense. The ISAR has taken up this initiative to lead the way forward in establishing practice guidelines for the safe and ethical use of ARTs in our country. These guidelines discuss the points to consider before the starting of an IVF unit, to the designing of the laboratory, the staffing pattern and experience recommendations, laboratory safety guidelines, documentation and patient traceability, gamete traceability, handling biological material, the consumables and media, and different consents and checklists and also propose key performance indicators for the Indian scenario.

STUDY DESIGN SIZE DURATION

This is the report of a 2-day consensus meeting where two moderators were assigned to a group of experts to collate information on safe and ethical ivf practices in INDIA. This meeting utilised surveys, available scientific evidence and personal laboratory experience into various presentations by experts on pre-decided specific topics.

PARTICIPANTS/MATERIALS SETTING METHODS

Expert professionals from ISAR representing clinical and embryology fields.

MAIN RESULTS AND THE ROLE OF CHANCE

The report is divided in various components including the regulations, the various requirements for an ART center, qualifications and trainings, recommendations on good practices and quality management: the report and recommendations of the expert panel reflect the discussion on each of the topics and try to lay down good practice points for labs to follow.

LIMITATIONS REASONS FOR CAUTION

The recommendations are solely based on expert opinion. Future availability of data may warrant an update of the same.

WIDER IMPLICATIONS OF THE FINDINGS

These guidelines can help labs across the country to standardise their ART services and improve clinical outcomes.

STUDY FUNDING/COMPETING INTERESTS

The consensus meeting and writing of the paper was supported by funds from CooperSurgical India.

Fertility technologies and how to optimize laboratory performance to support the shortening of time to birth of a healthy singleton: a Delphi consensus

PURPOSE

To explore how the assisted reproductive technology (ART) laboratories can be optimized and standardized to enhance embryo culture and selection, to bridge the gap between standard practice and the new concept of shortening time to healthy singleton birth.

METHODS

A Delphi consensus was conducted (January to July 2018) to assess how the ART laboratory could be optimized, in conjunction with existing guidelines, to reduce the time to a healthy singleton birth. Eight experts plus the coordinator discussed and refined statements proposed by the coordinator. The statements were distributed via an online survey to 29 participants (including the eight experts from step 1), who voted on their agreement/disagreement with each statement. Consensus was reached if ≥ 66% of participants agreed/disagreed with a statement. If consensus was not achieved for any statement, that statement was revised and the process repeated until consensus was achieved. Details of statements achieving consensus were communicated to the participants.

RESULTS

Consensus was achieved for all 13 statements, which underlined the need for professional guidelines and standardization of lab processes to increase laboratory competency and quality. The most important points identified were the improvement of embryo culture and embryo assessment to shorten time to live birth through the availability of more high-quality embryos, priority selection of the most viable embryos and improved cryosurvival.

CONCLUSION

The efficiency of the ART laboratory can be improved through professional guidelines on standardized practices and optimized embryo culture environment, assessment, selection and cryopreservation methodologies, thereby reducing the time to a healthy singleton delivery.

An Ethical Assessment Tool (ETHAS) to Evaluate the Application of Assisted Reproductive Technologies in Mammals' Conservation: The Case of the Northern White Rhinoceros (Ceratotherium simum cottoni)

Assisted reproductive technologies (ARTs) can make a difference in biodiversity conservation. Their application, however, can create risks and raise ethical issues that need addressing. Unfortunately, there is a lack of attention to the topic in the scientific literature and, to our knowledge, there is no tool for the ethical assessment of ARTs in the context of conservation that has been described. This paper reports the first applications of the Ethical Assessment Tool (ETHAS) to trans-rectal ovum pick-up (OPU) and in vitro fertilization (IVF) procedures used in a northern white rhinoceros (Ceratotherium simum cottoni) conservation project. The ETHAS consists of two checklists, the Ethical Evaluation Sheet and the Ethical Risk Assessment, and is specifically customized for each ART procedure. It provides an integrated, multilevel and standardized self-assessment of the procedure under scrutiny, generating an ethical acceptability ranking (totally, partially, not acceptable) and a risk rank (low, medium, high), and, hence, allows for implementing measures to address or manage issues beforehand. The application of the ETHAS to the procedures performed on the northern white rhinoceros was effective in ensuring a high standard of procedures, contributing to the acceptability and improved communication among the project's partners. In turn, the tool itself was also refined through an iterative consultation process between experts and stakeholders.

Occupational health issues experienced by UK embryologists: informing improvements in clinical reproductive science practice

A consultation exercise was undertaken with UK embryologists to construct knowledge of the occupational health issues they experience in everyday practice. Data were obtained from 223 eligible survey responses. Work-related ill health was self-reported by 58.3% of respondents, 76.2% of whom reported multiple issues. The most frequently disclosed ill-health conditions were musculoskeletal disorders (45.3%) and stress and mental health problems (27.8%). Other issues with an incidence above 3% were ocular and auditory problems and needlestick and liquid nitrogen injuries. Shoulder injury or pain correspondingly increased in incidence with length of time in service. Absence from work and/or light duties were necessitated for 34.5% of those affected. Assessment of the evidence base for these work-related ill-health conditions explored contributory and ameliorating factors, which enabled a series of evidence-based recommendations to be formulated via the adoption of a GRADE-based framework.

ESHRE Clinical Embryologist certification: the first 10 years

STUDY QUESTION

What has the ESHRE programme ‘ESHRE Certification for Clinical Embryologists’ achieved after 10 years?

SUMMARY ANSWER

The post-exam analysis showed a pass rate of 60% for Clinical and 50% for Senior Clinical Embryologists and a high level of internal consistency of all exams, leading to a total of 773 certified Clinical and 493 Senior Clinical Embryologists over the decade.

WHAT IS KNOWN ALREADY

In an ESHRE survey on the educational and professional status of Clinical Embryology in Europe, it was found that education of laboratory personnel working in the field of assisted reproduction is highly variable between countries. In 2008, ESHRE introduced a programme, curriculum and certification in the field of Clinical Embryology. Knowledge gained by postgraduate study of recommended literature, following a clear curriculum, is verified by a written two-level exam for obtaining a certificate for Clinical (basic) or Senior Clinical (advanced) Embryologists. With a total of 1266 certificates awarded over a period of 10 years and recognition by the Union Européenne des Médecins Spécialistes and their Council for European Specialists Medical Assessment, the ESHRE Clinical Embryology exams have become an internationally recognized educational standard in the field of Clinical Embryology.

STUDY DESIGN, SIZE, DURATION

A retrospective analysis of all applications for ESHRE Clinical (2009–2018) and Senior Clinical Embryologist Certification (2008–2018) and exam results of the first decade was carried out by the Steering Committee for Clinical Embryologist Certification.

PARTICIPANTS/MATERIALS, SETTING, METHODS

A total of 2894 applications for ESHRE Certification for Clinical Embryologists and the results of 10 exams for the Clinical (1478 candidates) and 11 exams for Senior Clinical (987 candidates) levels were analysed. A detailed post-exam retrospective analysis was performed regarding difficulty, discrimination and reliability levels of 1600 multiple-choice questions (MCQs) with a single best answer among four options, from eight different curriculum topics (Basic cell biology, Genetics, Developmental biology, Female reproduction, Male reproduction, IVF laboratory, Cryopreservation and Laboratory management), representing the core theoretical knowledge of Clinical Embryology. Difficulty levels of the MCQs were subsequently compared regarding each topic and each yearly exam. The participation and success rates in the ESHRE Clinical Embryology exams were also assessed in terms of the educational and geographic backgrounds of candidates.

MAIN RESULTS AND THE ROLE OF CHANCE

Over the 10 years studied, the mean pass rate for the Clinical Embryologist exam was 60% (range 41–86%), and for the Senior Clinical Embryologist exam was 50% (range 34–81%). On average, 63% European candidates and 35% non-European candidates passed the Clinical Embryologist exam, while 52% European candidates and 31% non-European candidates passed the Senior Clinical Embryologist exam. The candidates’ educational level impacted on the success of the Clinical Embryologist exam but not of the Senior Clinical Embryologist exam. The mean difficulty indices by study topic showed that in the period of 10 years, there were no statistically significant differences between topics, for either the Clinical or Senior Clinical Embryologist exams. However, the overall exam difficulty varied between years. Reassuringly, the exam MCQ discrimination and reliability indices always showed a high level of internal consistency in all exams.

LIMITATIONS, REASONS FOR CAUTION

Some data from the initial ESHRE certification programme were not obtained electronically, in particular data for education, implying tables and figures reflect the specified valid data periods. Several countries exhibit different study profiles for those working in ART laboratories, such that laboratory technicians/technologists predominate in some countries, while in others only biologists and medical doctors are allowed to work with human embryos. Such differences could consequently affect the exam performance of candidates from specific countries.

WIDER IMPLICATIONS OF THE FINDINGS

The ESHRE exams on Clinical Embryology are the most widely, internationally accepted tests of knowledge in the rapidly growing area of human reproduction. Clinical Embryology is increasingly recognized as a specific discipline for scientific staff who are collaborating closely with clinicians in managing human infertility through medically assisted reproduction. The analysis of the first 10 years of application of a two-level exam for Clinical Embryology shows a consistent high quality and reliability of the exam and MCQs used. These results represent an important follow-up of the quality of the ESHRE Certification programme for Clinical Embryologists, and convincingly position Clinical Embryology in the wider group of health disciplines that are harmonized through professional bodies such as ESHRE and European Board & College of Obstetrics and Gynaecology. The exams provide a clear step towards the increasing professional recognition and establishment of Clinical Embryology within health systems at both European and international level.

STUDY FUNDING/COMPETING INTEREST(S)

No competing interest. All costs of the Steering Committee meetings were covered by ESHRE.

[Impact of air quality on practices and results in the IVF laboratory]

The concept of Air Quality often refers to particulate and microbiological contamination of ambiant air. European Directive 2006/86/CE encompass the IVF process and specify a class A air quality for manipulation of tissue and cells, in a class D environment (A over D rule). Recognizing the paramount importance of ensuring the highest microbiological and particulate safety in the IVF laboratory, it is equally important to take into account practicability issues and the financial burden of these recommendations, as well as the utter need to protect gametes and embryo viability during their IVF journey. The usefulness of such stringent recommendations may also be questionned given the absence of published cases of airborne contaminations and related patients infections after embryo transfer. The European directive stems from pharmaceutical standards and were not specifically designed for human IVF. Gametes and embryos are indeed extremely sensitive to physical and chemical stress and require strict temperature, osmolarity and pH control, as well as an absence of chemical contamination during manipulation and culture. These conditions are hardly obtained when using laminar flow hoods. Following concerns raised by many experts in the field, exceptions to the A over D rule were added in the 2006/86/CE Directives. This narrative review discusses all these aspects in a critical way and compare scientific and legal requirements applying to IVF practices in different regions of the world.

Cumulative live birth rates and perinatal outcomes with the use of time-lapse imaging incubators for embryo culture: a retrospective cohort study of 1882 ART cycles

OBJECTIVE

Comparison of live birth rates and the perinatal outcomes after fresh and frozen embryo transfer between time-lapse imaging (TLI) and standard culture (SC) incubators.

DESIGN

Retrospective cohort study.

SETTING

A single tertiary level IVF unit.

POPULATION

Women undergoing IVF between January 2014 and October 2015.

METHODS

Comparison was done between 1064 IVF cycles using TLI (TLI cycles) and 818 IVF cycles using SC (SC cycles).

MAIN OUTCOME MEASURES

Cumulative live birth rate per oocyte retrieval and perinatal outcomes including birthweight, gestational age, preterm birth (PTB) (<37 weeks), early preterm birth (PTB; <32 weeks), low birthweight (LBW; <2500 g), very LBW (<1500 g) and macrosomia (>4500 g).

RESULTS

The fresh embryo transfer live birth rate was noted to be higher for TLI cycles [TLI 36.8 versus SC 33.9%, adjusted odds ratio (aOR) 1.28, 95% CI 1.05-1.57], but the frozen embryo transfer live birth rates were not significantly different. The mean birthweight was higher in the TLI group after both fresh [adjusted mean difference (aMD) 174.78 g, 95% CI 64.80-284.77] and frozen embryo transfers (aMD 175.91 g, 95% CI 16.98-334.84). After a fresh embryo transfer, there was a lower risk of early PTB and very LBW in the TLI group. Among frozen embryo transfers, there was a lower risk of early PTB and LBW in the TLI group.

CONCLUSIONS

TLI incubators are associated with improved perinatal outcomes and higher mean birthweight after fresh and frozen embryo transfer.

TWEETABLE ABSTRACT

Time-lapse imaging incubators in IVF improve perinatal outcomes after both fresh and frozen embryo transfers.

The Vienna consensus: report of an expert meeting on the development of ART laboratory performance indicators

This proceedings report presents the outcomes from an international workshop supported by the European Society of Human Reproduction and Embryology (ESHRE) and Alpha Scientists in Reproductive Medicine, designed to establish consensus on definitions and recommended values for Indicators for the assisted reproductive technology (ART) laboratory. Minimum performance-level values ('competency') and aspirational ('benchmark') values were recommended for a total of 19 Indicators, including 12 Key Performance Indicators (KPIs), five Performance Indicators (PIs), and two Reference Indicators (RIs).

The Vienna consensus: report of an expert meeting on the development of art laboratory performance indicators

STUDY QUESTION

What are appropriate performance indicators (PIs) for ART laboratories for use in monitoring 'fresh' IVF and ICSI cycles?

SUMMARY ANSWER

Minimum performance (competence) levels and aspirational (benchmark) values were recommended for a total of 19 indicators, including 12 key PIs (KPIs), five PIs and two reference indicators (RIs).

WHAT IS ALREADY KNOWN

PIs are necessary for systematic monitoring of the laboratory and an important element within the Quality Management System. However, there are no established PIs for ART laboratories and there is very little evidence on the topic.

STUDY DESIGN SIZE DURATION

This is the report of a 2-day consensus meeting of expert professionals. As a starting point for the discussion, two surveys were organized to collect information on indicators used in IVF laboratories. During the meeting, the results of the surveys, scientific evidence (where available), and personal clinical experience where integrated into presentations by experts on specific topics. After presentation, each proposed indicator was discussed until consensus was reached within the panel.

PARTICIPANTS/MATERIALS SETTING METHODS

Expert professionals representing different countries and settings convened in the consensus meeting.

MAIN RESULTS AND THE ROLE OF CHANCE

The paper is divided in two parts: the workshop report and the recommendations of the expert panel. The second part reflects the discussion on each of the indicators, with the agreed definition, competence level and benchmark value for each of the 19 indicators, including 12 KPIs, 5 PIs and 2 RIs.

LIMITATIONS REASONS FOR CAUTION

The KPIs are mainly based on expert opinion. Future research may warrant an update of the recommended KPIs, their definition and the competence level and benchmark values.

WIDER IMPLICATIONS OF THE FINDINGS

Based on the information presented, each ART laboratory should select its own set of KPIs founded on laboratory organization, and processes.

STUDY FUNDING/COMPETING INTERESTS

The consensus meeting and writing of the paper was supported by funds from ESHRE and Alpha. Alpha gratefully acknowledges the following organizations for their financial support, through the provision of unrestricted educational grants: Global Fertility Alliance, Merck, Origio and Vitrolife. There are no conflicts of interest to disclose.

Optimizing human semen cryopreservation by reducing test vial volume and repetitive test vial sampling

OBJECTIVE

To investigate optimal test vial (TV) volume, utility and reliability of TVs, intermediate temperature exposure (-88°C to -93°C) before cryostorage, cryostorage in nitrogen vapor (VN2) and liquid nitrogen (LN2), and long-term stability of VN2 cryostorage of human semen.

DESIGN

Prospective clinical laboratory study.

SETTING

University assisted reproductive technology (ART) laboratory.

PATIENT(S)

A total of 594 patients undergoing semen analysis and cryopreservation.

INTERVENTION(S)

Semen analysis, cryopreservation with different intermediate steps and in different volumes (50-1,000 μL), and long-term storage in LN2 or VN2.

MAIN OUTCOME MEASURE(S)

Optimal TV volume, prediction of cryosurvival (CS) in ART procedure vials (ARTVs) with pre-freeze semen parameters and TV CS, post-thaw motility after two- or three-step semen cryopreservation and cryostorage in VN2 and LN2.

RESULT(S)

Test vial volume of 50 μL yielded lower CS than other volumes tested. Cryosurvival of 100 μL was similar to that of larger volumes tested. An intermediate temperature exposure (-88°C to -93°C for 20 minutes) during cryopreservation did not affect post-thaw motility. Cryosurvival of TVs and ARTVs from the same ejaculate were similar. Cryosurvival of the first TV in a series of cryopreserved ejaculates was similar to and correlated with that of TVs from different ejaculates within the same patient. Cryosurvival of the first TV was correlated with subsequent ARTVs. Long-term cryostorage in VN2 did not affect CS.

CONCLUSION(S)

This study provides experimental evidence for use of a single 100 μL TV per patient to predict CS when freezing multiple ejaculates over a short period of time (<10 days). Additionally, semen cryostorage in VN2 provides a stable and safe environment over time.