Fertilization after intracytoplasmic sperm injection with cryopreserved testicular spermatozoa

A review of methods for preserving male fertility

Male infertility is responsible for 50% of men's health problems and has always been a concern for personal and social issues. A survey of global statistics suggests an increase in infertility rate as one of the critical issues documented in studies. There are different ways of maintaining fertility in men, depending on their age. In this paper, we review the preservation methods used for fertility treatment in Iran and other countries. Available data were reviewed from Google Scholar, PubMed, Scopus, Web of Science, IranMedex, MEDLIB, IranDoc and Scientific Information Database and searched for articles published up to 2018, using the medical subject heading (MeSH) terms for cryopreservation, sperm, testicular, spermatogonia stem cell, male infertility and/or Iranian and in the world, to provide evidence from evaluation of fertility preservation the methods. Based the search strategy, 274 manuscripts were found. After reviewing the titles, abstracts and manuscripts in their entirety, 119 articles were obtained and selected according to the eligibility criteria. The 85 studies mentioned above were divided into three categories (sperm, testis, and spermatogonia stem cells (SSCs)), and methods of fertility preservation were investigated. Ways to maintain male fertility were different depending on age, and included sperm, testicular, and SSC freezing. The number of studies on testicular tissue and SSCs was low for human samples, and more studies are still needed. Sperm freezing at infertility centres is the top for male fertility preservation.

Intracytoplasmic sperm injection with fresh versus cryopreserved testicular sperm in azoospermic patients

Background

The purpose of this study is to compare the outcome of intracytoplasmic sperm injection (ICSI) using fresh sperm versus frozen-thawed sperm in both obstructed and non-obstructed azoospermias. This retrospective study included 159 ICSI cycles from 126 couples. In 91 obstructed azoospermia cases, 66 cycles were treated with fresh testicular sperm and 25 cycles were treated with frozen-thawed testicular samples. In 68 non-obstructed azoospermia cases, 32 cycles were treated with fresh testicular sperm and 36 cycles were treated with frozen-thawed testicular sperm, and the main measure and outcomes calculated are fertilization rate, clinical pregnancy, and live birth rate.

Results

In case of obstructed azoospermia, there were no statistically significant differences between fresh sperm and frozen-thawed testicular sperm used for ICSI regarding fertilization rate, clinical pregnancy rate, and live birth rate as shown (57%, 47%, 0.093 p value; 23.7%, 17.4%, 0.54 p value; and 11.9%, 8.7%, 0.68 p value, respectively). Non-obstructed azoospermia cases also show no significant differences in fertilization rate (37%, 36%, 0.91 p value), clinical pregnancy rate (20%, 14.3%, 0.58 p value), and live birth rate (4%, 3.6%, 0.93 p value).

Conclusion

Cryopreservation of testicular sperm is reliable if carried out before ovulation induction especially in cases with non-obstructive azoospermia

Chapter 5 Slow Freezing of Human Sperm

Cryopreservation of human spermatozoa is a highly efficient procedure for managing male fertility, and much of its successful application seems to have a crucial impact on the reproductive outcome of assisted reproduction technologies. Here, we present, explain, and describe the slow freezing method for preserving human spermatozoa, which is currently the most commonly used freezing technique in most clinical andrology laboratories.

Chapter 1 Historical Background on Gamete and Embryo Cryopreservation

This chapter describes the development of the science of cryopreservation of gametes and embryos of various species including human. It attempts to record in brief the main contributions of workers in their attempts to cryopreserve gametes and embryos. The initial difficulties faced and subsequent developments and triumphs leading to present-day state of the art are given in a concise manner. The main players and their contributions are mentioned and the authors' aim is to do justice to them. This work also attempts to ensure that credit is correctly attributed for significant advances in gamete and embryo cryopreservation. In general this chapter has tried to describe the historical development of the science of cryopreservation of gametes and embryos as accurately as possible without bias or partiality.

Efficacy of cryopreservation of embryos generated by intracytoplasmic sperm injection with spermatozoa from frozen testicular tissue

PURPOSE

To evaluate the viability of frozen embryos generated by intracytoplasmic sperm injection (ICSI) with frozen testicular spermatozoa.

METHODS

A total of 68 fresh embryo transfer (ET) cycles and 85 subsequent frozen-thawed ET (FET) cycles were grouped according to the source of spermatozoa: fresh testicular spermatozoa (TESE) or frozen-thawed testicular spermatozoa (t-TESE).

RESULTS

There were no significant differences in the age of female patients, number of oocytes, or fertilization rates in fresh ET cycles with TESE (TESE-fresh ET) versus t-TESE (t-TESE-fresh ET). The rate of embryo survival after thawing (95.7 % vs. 94.0 %) was similar in frozen ET cycles (FET) with TESE (TESE-FET) and with t-TESE (t-TESE-FET). While there were significant differences in the proportion of good quality embryos, no statistical differences were found in the pregnancy or clinical abortion rates between the two groups. Moreover, delivery rates were not significantly different.

CONCLUSIONS

Although the proportion of good quality embryos was affected by cryopreservation of testicular tissue, embryo survival rate was not. As well, subsequent pregnancy could be achieved successfully via t-TESE-FET cycles. Therefore, FET is not affected by the cryopreservation of testicular tissue, and avoids further oocyte retrieval and TESE procedures.

Recovery, Preparation, Storage and Utilization of Spermatozoa for Fertility Preservation in Cancer Patients and Sub-Fertile Men

Sperm cryopreservation is an important part of an infertility program for patients undergoing infertility treatments, fertility assurance for vasectomy cases, and for fertility preservation due to cancer or other medical conditions. With recent developments in reproductive technology, even men with severely impaired sperm parameters can benefit from cryopreservation as procedures such as intra-cytoplasmic sperm injection (ICSI) require only a few sperm to achieve fertilization and pregnancy. The increasing success of cancer treatment and concerted efforts to ensure quality of life after successful treatment have placed great emphasis on the need to preserve the reproductive capability of young men. It is a highly effective method of protecting male fertility potential, and involves collection, freezing, and long-term storage of sperm. Based on the etiological condition of the patients, sperm can be collected by ejaculation or by surgical retrieval from epididymis or testes. The option to bank sperm should be offered systematically to all patients who may benefit. However, this is not a standard of practice yet; it may be overlooked due to lack of physician awareness regarding the need for fertility preservation and the effectiveness of this option, and/or overestimating the limitations of poor baseline sperm quality leading physician to view cryopreservation as futile. Failure to offer cryopreservation ignores the only possible reproductive option available to certain patients.

Testicular sperm from patients with obstructive and nonobstructive azoospermia: aneuploidy risk and reproductive prognosis using testicular sperm from fertile donors as control samples

OBJECTIVE

To establish a baseline incidence of chromosomal abnormalities in testicular sperm of fertile men and to determine the best control sample for comparisons with azoospermic males to estimate their reproductive prognosis.

DESIGN

Prospective study.

SETTING

Infertility clinic.

PATIENT(S)

Sixteen obstructive azoospermic (OA) and 19 nonobstructive azoospermic patients (NOA). Control samples were ejaculated sperm from ten fertile donors and testicular sperm from ten other fertile donors.

INTERVENTION(S)

Fluorescence in situ hybridization (FISH) in sperm.

MAIN OUTCOME MEASURE(S)

Sperm numerical abnormalities for chromosomes 13, 18, 21, X, and Y; ongoing implantation and pregnancy rates in intracytoplasmic sperm injection (ICSI) cycles.

RESULT(S)

In control samples, testicular sperm showed higher incidences of diploidy (0.27% vs. 0.10%) and disomy for chromosomes 13 (0.16% vs. 0.07%), 21 (0.25% vs. 0.12%), and sex chromosomes (0.34% vs. 0.21%) than ejaculated sperm. Comparisons with ejaculated control samples showed 12.5% OA and 68.4% NOA patients having significantly higher incidence of sperm chromosomal abnormalities. Compared with testicular control subjects, fewer OA (6.3%) and NOA (42.1%) patients had chromosomally abnormal sperm. NOA patients had lower ongoing implantation and pregnancy rates than OA patients, particularly those with abnormal FISH compared with testicular control samples.

CONCLUSION(S)

Sperm FISH analysis using testicular sperm control samples better identifies NOA patients with a lower likelihood of reproductive success.

Optimal use of fresh and frozen-thawed testicular sperm for intracytoplasmic sperm injection in azoospermic patients

PURPOSE

To optimize the use of fresh and frozen-thawed testicular biopsy specimens from patients with azoospermia.

METHODS

Fifty-one patients suffering from obstructive and non-obstructive azoospermia underwent testicular sperm extraction (TESE). The specimens were divided and used for either in vitro maturation or freezing for a future intracytoplasmic sperm injection (ICSI) cycle.

RESULTS

At initial testicular sperm extraction, very few motile spermatozoa were seen. After 24 h of in vitro maturation, sperm motility increased remarkably, with a maximum motility rate seen between 48 and 72 h of culture. Motile spermatozoa were observed up to 120 h in culture. In the 22 fresh ICSI cycles, a total of 294 oocytes were injected using motile sperm and 212 oocytes demonstrated normal 2PN formation (fertilization rate, 72.1%). In 36 frozen-thawed ICSI cycles, a total of 454 oocytes were injected and 302 oocytes became 2PN (66.5%). On day 3, high quality embryos were observed in 54.2% of fresh cycles and 54.1% of frozen cycles (P > 0.05). The clinical pregnancy rate did not show a significant difference between using fresh (59%) and frozen (55.5%) testicular biopsy sperm for ICSI (P > 0.05), but the embryo implantation rates did differ significantly between fresh (29.5%) and frozen-thawed (22.2%) cycles (P < 0.05). A total of 33 healthy babies have been born from 22 women, giving birth after 58 embryo transfer attempts (38%).

CONCLUSION

The freezing and in vitro culturing of testicular biopsy tissue is a very reliable approach for the management of testicular biopsy specimens from azoospermic patients, and offers the possibility of several treatments of IVF/ICSI from a single sample.

Cumulative pregnancy rate after ICSI with cryopreserved testicular tissue in non-obstructive azoospermia

The aim of the present study was to describe a simplified and inexpensive method of testicular tissue freezing, to assess the cumulative clinical pregnancy rate (CPR) by this technique, and to provide useful information for counselling couples with non-obstructive azoospermia. One hundred and sixty-five couples with non-obstructive azoospermic males pursuing assisted conception, from December 1995 to December 2002, were included. In all cases, the testicular tissue retrieved by open multiple-biopsy (both sides, by testicular sperm extraction) was frozen using a simple liquid nitrogen vapour freezing technique and was stored in liquid nitrogen thereafter. Only mature spermatozoa were used for intracytoplasmic sperm injection (ICSI) after thawing. Expected CPR were calculated using the Kaplan-Meier survival analysis. A total of 281 cycles were performed resulting in 53 clinical pregnancies. Crude and expected CPR (95% confidence intervals) after three cycles were 32.1 (25.7-40.1) and 55.7% (37.0-74.4) respectively. In conclusion, this simplified method for freezing testicular tissue resulted in a satisfactory outcome after ICSI in cases of non-obstructive azoospermia.

Intracytoplasmic sperm injection with motile and immotile frozen-thawed testicular spermatozoa (the Hungarian experience)

The authors summarize their experience in 75 in vitro fertilization cycles, where frozen-thawed testicular spermatozoa were used for intracytoplasmic sperm injection. In 32 cases, motile spermatozoa could be observed in the frozen-thawed sample. In 34 cases, motility could be induced by pentoxifylline and in nine cases immotile spermatozoa, selected with hypoosmotic swelling test, were used for fertilization. The fertilization rates obtained with motile and immotile spermatozoa (66.1% versus 52.3%) were not significantly different. Our data demonstrate that freezing of testicular spermatozoa opened new possibilities for the treatment of azoospermic men. The clinical pregnancy rate per embryo transfer (ET) (21.87%) was comparable with previous results use of fresh testicular spermatozoa (27.7%). The quality and number of transferred embryos had the most significant impact on the pregnancy rate. The fertilization rate and frequency distribution of good-quality embryos were lower in the case of immotile spermatozoa, and pregnancies were only achieved when motile spermatozoa had been used.

Crude cumulative delivery rate following ICSI using intentionally frozen–thawed testicular spermatozoa in 51 men with non-obstructive azoospermia

This prospective study evaluated the crude cumulative delivery rate following delayed intracytoplasmic sperm injection (ICSI) using spermatozoa recovered by testicular extraction (TESE) and intentionally frozen in men with non-obstructive azoospermia (NOA). This procedure can be termed 'cryoTESE-ICSI'. This study involved a series of 118 patients who underwent testicular biopsy for diagnosis of NOA in the period from January 1998 to December 2002. Testicular histology confirmed the diagnosis of NOA. Testicular parenchyma was obtained surgically from both testicles under general anaesthesia. Cryopreservation of spermatozoa was performed in 51 of 118 patients (43%). Ninety-nine delayed ICSI procedures were performed. Frozen-thawed suspensions were used in all cycles. Application of pentoxifylline was required to stimulate spermatozoa in 52% of cases. Fertilization, embryo transfer, and ongoing pregnancy rates were 60, 98 and 29% respectively. The crude cumulative delivery rate was 49% after two cycles and 57% after four cycles. A total of 39 healthy children were born in 29 deliveries. Thus, cryoTESE-ICSI is an effective procedure for routine use in patients with NOA. The main advantages of cryoTESE-ICSI are to (i) avoid repeated surgical biopsy, (ii) ensure the availability of spermatozoa when the ovarian stimulation cycle is begun, and (iii) allow programmed biopsy and therefore dissociate it from ICSI.

Should diagnostic testicular sperm retrieval followed by cryopreservation for later ICSI be the procedure of choice for all patients with non-obstructive azoospermia?

BACKGROUND

This was a retrospective study to determine if diagnostic testicular biopsy followed by cryopreservation should be the procedure of choice for all patients with testicular failure.

METHODS

The first part of the study analysed 97 ICSI cycles scheduled with frozen-thawed testicular sperm for 69 non-obstructive azoospermia (NOA) patients. The second part focused on a subgroup of 32 patients who underwent 42 ICSI cycles with frozen and 44 cycles with fresh testicular sperm. Sperm characteristics, fertilization, embryo quality, pregnancy and implantation rates were evaluated.

RESULTS

Part I: The average time needed to find sperm was 113 min per cycle and 17 min per individual sperm. Fertilization rate, embryo transfer rate, ongoing pregnancy and implantation rates were 58.4%, 83%, 20.8% and 11.3%, respectively. Part II: The search time per sperm was higher (P=0.016) in frozen (18 min) than in fresh suspensions (13 min). A higher embryo transfer rate was observed in fresh cycles than in frozen cycles (93.2% vs 76.2%, P=0.028). Fertilization, ongoing pregnancy and implantation rates were comparable for the two groups.

CONCLUSIONS

Even in a programme with low-restrictive criteria for patient allocation and for sperm cryopreservation, diagnostic testicular biopsy followed by cryopreservation can be the procedure of choice for patients with testicular failure.

Influence of motility on the outcome of in vitro fertilization/intracytoplasmic sperm injection with fresh vs. frozen testicular sperm from men with obstructive azoospermia

OBJECTIVE

To assess the efficacy of fresh vs. frozen testicular sperm on fertilization and pregnancy using intracytoplasmic sperm injection.

DESIGN

Retrospective study.

SETTING

Hospital-based infertility research laboratory.

PATIENT(S)

One hundred sixty patients with obstructive azoospermia undergoing testicular sperm extraction (TESE).

INTERVENTION(S)

Sections of seminiferous tubule were cryopreserved after TESE. Sperm motility and fertilizing ability were determined after thawing seminiferous tubule sections.

MAIN OUTCOME MEASURES

Sperm motility and optimal fertilization and pregnancy rate.

RESULT(S)

Intracytoplasmic sperm injection was performed using fresh testicular sperm (fresh-sperm group; 84 cases) and thawed seminiferous tubules (thawed-sperm group; 177 cases). The overall fertilization rate was 65.4%, and the pregnancy rate was 34.0%. In the fresh-sperm group, the fertilization rate was 70.9%, and the pregnancy rate was 38.8%. In the thawed-sperm group, the fertilization rate was 62.7%, and the pregnancy rate was 21.7%. Fertilization rates were higher using fresh motile sperm vs. nonmotile sperm (77.0% vs. 29.3%). Pregnancy rates were higher using fresh motile sperm vs. nonmotile sperm (44.3% vs. 20.0%). The fertilization and pregnancy rates of motile vs. nonmotile sperm extracted from the thawed seminiferous tubule were 70.0% vs. 50.9% and 33.9% vs. 27.3%, respectively. Motile spermatozoa could be obtained several hours after thawing in most of the cases.

CONCLUSION(S)

Optimal fertilization and pregnancy rates were achieved using fresh vs. frozen sperm obtained using TESE when motile sperm were identified. Motile spermatozoa provided superior results to nonmotile sperm and are necessary for optimal fertilization and pregnancy outcomes.

The effects of female age on the outcome of testicular sperm extraction and intracytoplasmic sperm injection in infertile patients with azoospermia

INTRODUCTION

Testicular sperm extraction (TESE) is well-defined procedure for surgical sperm retrieval in obstructive and non-obstructive azoospermia. This study was focused on the effectiveness of testicular sperm extraction and intracytoplasmic sperm injection (ICSI) for azoospermic men with different female age subgroups.

MATERIALS AND METHODS

A total of 107 men with azoospermia underwent TESE and ICSI treatment. The women were examined in three groups 20-29, 30-34 and 35 years or older. The main outcome in this study was fertilization and pregnancy rates with TESE and ICSI.

RESULTS

Spermatozoa were successfully retrieved during 97 of 107 (90.7%) TESE attempts, resulting in the fertilization of 286 of 563 (50.4%) injected metaphase II oocytes. Two hundred and fifty-five of them were transferred (89.8%). The clinical pregnancy rate and ongoing pregnancy rate per embryo transfer were 22.5% and 20.6% respectively. When comparing the fertilization and pregnancy rates, it was observed that women between the ages of 20-29 years had significantly higher pregnancy rates than women over 34 years of age (p < 0.05).

CONCLUSION

The female age is a major factor in determining successful implantation in ICSI.

Five years experiences with microinjection of testicular spermatozoa into oocytes in Hungary

The aim of the study was to summarize our five years experience (1996-2000) of testicular spermatozoa for intracytoplasmic sperm injection in Hungary. The influence of sperm count, maternal age, number of transferred embryos, and application of assisted hatching on outcome was investigated. Testicular spermatozoa were retrieved by microsurgical testicular sperm extraction. Samples were classified depending on the number of spermatozoa. Indication for testicular sperm extraction in conjunction with intracytoplasmic sperm injection was severe azoospermia or azoospermia combined with tubal origin infertility. Ovarian stimulation was carried out using an ultrashort protocol with GnRH agonist and gonadotrophin. Intracytoplasmic sperm injection was performed without PVP. Embryos were cultured for 48 or 72 h before embryo transfer. Indications for assisted hatching included elevated maternal age, increased zona thickness or at least two previous unsuccessful IVF cycles. Testicular spermatozoa were successfully retrieved in 218 out of 273 cases. Extreme low sperm count was found more frequently in cases of nonobstructive azoospermia. No significant differences were observed in fertilization rate (61.1% vs. 51.7%) or clinical pregnancy rate (29.0% vs. 26.7%) between patients with obstructive or nonobstructive azoospermia. Maternal age, number of transferred embryos and application of assisted hatching had a significant effect on outcome. A total of 55 clinical pregnancies were achieved, including 14 sets of twins, three sets of triplets and two sets of quadruplets. It is concluded that testicular sperm extraction is an efficient way of obtaining testicular spermatozoa, allowing not only successful fertilization by ICSI, but also freezing of testicular spermatozoa for use in subsequent cycles.

Predictive value of testicular histology in secretory azoospermic subgroups and clinical outcome after microinjection of fresh and frozen-thawed sperm and spermatids

BACKGROUND

A retrospective study was carried out on 159 treatment cycles in 148 secretory azoospermic patients to determine whether histopathological secretory azoospermic subgroups were predictive for gamete retrieval, and to evaluate outcome of microinjection using fresh or frozen-thawed testicular sperm and spermatids.

METHODS

Sperm and spermatids were recovered by open testicular biopsy and microinjected into oocytes. Fertilization and pregnancy rates were assessed.

RESULTS

In hypoplasia, 97.7% of the 44 patients had late spermatids/sperm recovered. In maturation-arrest (MA; 47 patients), 31.9% had complete MA, and 68.1% incomplete MA due to a focus of early (36.2%) or late (31.9%) spermiogenesis. Gamete retrieval was achieved in 53.3, 41.2 and 93.3% of the cases respectively. In Sertoli cell-only syndrome (SCOS; 57 patients), 61.4% were complete SCOS, whereas incomplete SCOS cases showed one focus of MA (5.3%), or of early (29.8%) and late (3.5%) spermiogenesis. Only 29.8% of the patients had a successful gamete retrieval, 2.9% in complete and 77.3% in incomplete SCOS cases. In total, there were 87 ICSI, 39 elongated spermatid injection (ELSI) and 33 round spermatid injection (ROSI) treatment cycles, with mean values of fertilization rate of 71.4, 53.6 and 17%, and clinical pregnancy rates of 31.7, 26.3 and 0% respectively.

CONCLUSIONS

Histopathological subgroups were positively correlated with successful gamete retrieval. No major outcome differences were observed between testicular sperm and elongated spermatids, either fresh or frozen-thawed. However, injection of intact round-spermatids showed very low rates of fertilization and no pregnancies.

Efficiency of using frozen-thawed testicular sperm for multiple intracytoplasmic sperm injections

PURPOSE

To compare fertilization and pregnancy rates of fresh and frozen-thawed testicular sperm injections (TESE-ICSI).

METHODS

Sperm collected from the testes of 28 azoospermic patients by an open testicular biopsy technique was used for initial ICSI or cryopreserved.

RESULTS

Fresh-sperm ICSI treatment (28 cycles) resulted in a 58.1% fertilization rate and a 32.1% clinical pregnancy rate per embryo transfer, while frozen-thawed sperm (24 subsequent cycles) had rates of 54.5 and 29.2%, respectively. The PR was lower using frozen-thawed sperm from nonobstructive azoospermia patients (9.1%) than from obstructive azoospermia patients (46.2%). PR declined to 0% upon the fourth ICSI attempt.

CONCLUSIONS

Fertilization, embryo cleavage, and pregnancy rates were unaffected by fresh or frozen-thawed sperm use. A 57.1% cumulative clinical PR was achieved using the latter. The PR was significantly lower using frozen-thawed sperm from nonobstructive azoospermia patients than from obstructive azoospermia patients.

Serum inhibin B may be a reliable marker of the presence of testicular spermatozoa in patients with nonobstructive azoospermia

OBJECTIVE

To establish the predictive value of serum inhibin B levels as an indicator of the presence of testicular spermatozoa in nonobstructive azoospermia, compared with the traditional serum FSH marker.

DESIGN

Prospective study.

SETTING

Private high-complexity reproductive center with university affiliation.

PATIENT(S)

Seventy-eight patients with nonobstructive azoospermia, 15 patients with obstructive azoospermia, and 10 fertile volunteers.

INTERVENTION(S)

Blood samples, testicular sperm extraction, percutaneous epididymal sperm aspiration, and semen collection.

MAIN OUTCOME MEASURE(S)

Serum levels of inhibin B and FSH and presence of spermatozoa on TESE, PESA, or regular semen analysis.

RESULT(S)

Patients with nonobstructive azoospermia has significantly higher levels of serum FSH and significantly lower levels of inhibin B. Mean inhibin B serum levels were significantly higher in patients with nonobstructive azoospermia who had spermatozoa on TESE than in those in whom no spermatozoa were found (89.31 +/- 73.24 pg/mL vs. 19.23 +/- 22.34 pg/mL), but mean FSH serum levels did not have similar predictive power (21.37 +/- 12.92 IU/mL vs. 19.27 +/- 10.28 IU/mL). The cut-off level of inhibin B separating both groups, as determined by the receiver-operating characteristic curves, was >53 pg/mL.

CONCLUSION(S)

Serum inhibin B level seems to be more accurate than serum FSH level in prediction of the presence of testicular spermatozoa in patients with nonobstructive azoospermia.

Intracytoplasmic sperm injection with cryopreserved testicular spermatozoa

To assess if testicular sperm cryopreservation is a valid alternative to repetition of testicular sperm retrieval techniques, results of a cryopreservation technique in pills have been retrospectively analyzed. Enough motile spermatozoa for ICSI were obtained in 172 from 190 (90.5%) frozen-thawed testicular sperm samples. Overall, 249 couples underwent 390 ICSI cycles, 156 using fresh and 234 using cryopreserved testicular sperm. Mean two-pronuclear fertilization rates per cycle were not significantly different after ICSI with fresh (62.0%) or with cryopreserved (63.2%) spermatozoa. Mean embryo cleavage rate per cycle was higher in the fresh (90.6%) than in the cryopreserved (84.6%) group (P = 0.016). However, clinical pregnancy rates per cycle (28.2% with fresh vs 27.8% with cryopreserved), implantation rates (12.2% vs 13.1%) and ongoing pregnancy rates per cycle (22.4% vs 21.8%) were not significantly different. Cryopreservation of testicular spermatozoa is an effective technique that can be used both in obstructive and in non-obstructive azoospermia.

Outcome of ICSI cycles using frozen-thawed surgically obtained spermatozoa in poor responders to ovarian stimulation: cancellation or proceeding to ICSI?

OBJECTIVE

To investigate the ICSI outcome of the patients who produced four follicles or less after ovarian stimulation using frozen-thawed surgically obtained spermatozoa.

STUDY DESIGN

The patient cohort of this study was composed of a carefully selected group of 20 men suffering from obstructive and non-obstructive azoospermia and in whom spermatozoa had been seen in their harvested epididymal aspirates and testicular tissues and the cryopreserved specimens had been used for subsequent ICSI cycles. This group of men represent those in whom the female partners produced only four follicles or less after ovarian stimulation.

RESULTS

For the cases of obstructive azoospermia with MESA (n=6) a total of nine cycles was carried out. Four couples went through one cycle, one couple underwent two cycles, one couple accomplished three cycles. Out of the nine cycles, seven went to embryo transfer. No pregnancy occurred in the MESA-ICSI group of patients. The mean+/-S.D. number of oocytes per cycle was 2.556+/-1.236, the mean+/-S.D. number of embryos per transfer was 1.444+/-1.014. Two couples did not have an embryo replacement because of absence of fertilisation. The mean+/-S. D. number of gonadotropin ampoules was 53.88+/-37.30 and the mean+/-S.D. duration of ovarian stimulation was 13.38+/-4.534 days. For the cases of non-obstructive azoospermia with TESE (n=14) a total of 16 cycles was carried out. Thirteen couples went through one cycle, one couple accomplished three cycles. Out of the 16 cycles, 11 cycles went to embryo transfer. One pregnancy occurred in the TESE-ICSI group of patients, which produced live offspring. The mean+/-S.D. number of oocytes per cycle was 3.00+/-1.211, the mean+/-S.D. number of embryos per transfer was 1.313+/-1.195. Five couples did not have an embryo replacement, four of them because of absence of fertilisation and one because of abnormal fertilisation (3 PN). The mean+/-S.D. number of gonadotropin ampoules was 81. 77+/-53.40 and the mean+/-S.D. duration of ovarian stimulation was 16.71+/-3.667 days.

CONCLUSION

In our opinion, these data show that it is possible to achieve satisfactory fertilisation rates using frozen-thawed epididymal and testicular spermatozoa obtained from men with obstructive or non-obstructive azoospermia, but the limiting factor in reaching the stage of embryo transfer is the poor ovarian response to stimulation induction. It therefore seems preferable to cancel these cycles, in the hope that a better response might be obtained in a subsequent cycle, avoiding in this way financial and emotional implications.

Biological aspects of testicular sperm extraction

Since the first reports of successful pregnancies after treatment with intra cytoplasmic sperm injection (ICSI) in humans, intensive investigations focused on the use of testicular spermatozoa and immature sperm cells in the treatment of azoopsermic patients. Several studies explore the technical development of the preparation, isolation and cryo storage of testicular germ cells. Other studies focus on ICSI itself and try to identify the biochemical and biophysical processes involved in fertilisation after injection of a testicular sperm cell into a human oocyte. Indications for azoospermic patients to whom this first line treatment can be offered are becoming more defined. But one of the major concerns is of course the safety of the technique, especially, for the health and reproductive life of the babies born after application of ICSI with testicular germ cells. An evaluation of ICSI with testicular germ cells is presented in this manuscript.

In vitro fertilization outcomes after intracytoplasmic sperm injection with fresh or frozen-thawed testicular spermatozoa

OBJECTIVE

To compare the outcomes of intracytoplasmic sperm injection (ICSI) and in vitro fertilization (IVF) with fresh and cryopreserved testicular spermatozoa in patients with obstructive and nonobstructive azoospermia.

DESIGN

Retrospective analysis of consecutive ICSI cycles.

SETTING

Large urban reproductive medicine program.

PATIENT(S)

Twenty-nine patients with obstructive and nonobstructive azoospermia undergoing testicular sperm extraction for a total of 46 IVF-ICSI cycles (12 fresh, 34 frozen).

INTERVENTION(S)

Testicular sperm extraction, cryopreservation, and IVF-ICSI with fresh or frozen-thawed spermatozoa.

MAIN OUTCOME MEASURE(S)

Fertilization rates, embryo cleavage rates, embryo implantation rates, clinical pregnancy rates per cycle and per embryo transfer, and delivery and spontaneous abortion rates.

RESULT(S)

No statistically significant differences were noted in any of the parameters examined between IVF-ICSI cycles from fresh or frozen-thawed testicular spermatozoa. Fertilization rates were 56% with fresh vs. 61% with frozen-thawed testicular sperm, cleavage rates 92% vs. 95%, implantation rates 26% vs. 17%, clinical pregnancy rates per cycle 33% vs. 41%, and pregnancy rates per embryo transfer 33% vs. 45%, respectively. Delivery rates were 75% with fresh vs. 69.2% with frozen-thawed testicular sperm, and spontaneous abortion rates 25% and 30.8%, respectively.

CONCLUSION(S)

No differences were found in IVF-ICSI outcomes between cryopreserved and fresh testicular sperm. In addition, cryopreservation provides several advantages for the patients and reproductive team.

Use of frozen-thawed testicular sperm for intracytoplasmic sperm injection

OBJECTIVE

To determine the feasibility of using frozen-thawed testicular spermatozoa for intracytoplasmic sperm injection.

DESIGN

Prospective clinical study.

SETTING

A university hospital.

PATIENT(S)

One hundred seventy-five azoospermic men participating in a routine intracytoplasmic sperm injection program.

INTERVENTION(S)

The men underwent testicular biopsy for cryopreservation of tissue to be used in consecutive intracytoplasmic sperm injection treatment cycles. Their female partners underwent controlled ovarian hyperstimulation for conventional IVF treatment.

MAIN OUTCOME MEASURE(S)

Fertilization and pregnancy rates.

RESULT(S)

In 77% of the patients, spermatozoa could be harvested from the testis by an open testicular biopsy technique and used for intracytoplasmic sperm injection after freezing and thawing of testicular tissue. Histopathologic evaluation revealed a Sertoli cell-only pattern in 21%, maturation arrest in 60%, and hypospermatogenesis in 19% of the patients. In 2. 9% of the patients, carcinoma in situ or a germ cell tumor was detected. In all patients, viable spermatozoa could be visualized after the tissue samples were thawed. One hundred thirty-five intracytoplasmic sperm injection treatment cycles were performed, with a fertilization rate of 45% and a clinical pregnancy rate of 30% per oocyte retrieved.

CONCLUSION(S)

The use of frozen-thawed testicular tissue allows ovarian stimulation of the female partner to be timed and avoids cancellation of ovum pick-up when spermatozoa cannot be retrieved.

Extraction of testicular sperm from previously cryopreserved tissue in couples with or without transport of oocytes and testicular tissue

OBJECTIVE

To evaluate results of IVF and intracytoplasmic sperm injection (ICSI) with extraction of sperm from frozen-thawed testicular tissue.

DESIGN

Retrospective follow-up study.

SETTING

Fertility center.

PATIENT(S)

Thirty-five couples with transport of testicular tissue from a transport clinic and 125 local couples.

INTERVENTION(S)

Extraction of testicular sperm by maceration and enzymatic digestion from frozen-thawed testicular tissue before ICSI.

MAIN OUTCOME MEASURE(S)

Clinical pregnancy rate (PR) and implantation rate in couples with obstructive or nonobstructive azoospermia, motile or immotile sperm, and differing male serum FSH values.

RESULT(S)

The clinical PR per ET and implantation rate per embryo in couples with transport of testicular tissue were 40% and 18%, respectively, in cases of obstructive azoospermia and 37% and 26%, respectively, in cases of nonobstructive azoospermia. In the local couples, these rates were 42% and 19%, respectively, in cases of obstructive azoospermia and 18% and 10%, respectively, in cases of nonobstructive azoospermia. The implantation rates for ICSI were 26% with motile sperm and 11% with immotile sperm in the transport group and 16% and 8%, respectively, in the local group. Male serum FSH level did not clearly correlate with implantation rate.

CONCLUSION(S)

Clinical PR and implantation rate are not affected by transport of testicular tissue but are significantly affected by nonobstructive azoospermia and the use of immotile sperm. No major increase in chromosomal aberration or congenital malformation was noted in the offspring of this limited group.

Pregnancies achieved after frozen-thawed pronuclear oocytes obtained by intracytoplasmic sperm injection with spermatozoa extracted from frozen-thawed testicular tissues from non-obstructive azoospermic men

The use of frozen-thawed testicular tissue as a source of spermatozoa for intracytoplasmic sperm injection (ICSI) in non-obstructive azoospermia yields favourable fertilization and pregnancy rates while avoiding both repetitive biopsies and unexpected cycle cancellations. Spermatozoa were obtained from frozen-thawed testicular biopsy specimens from 67 non-obstructive azoospermic men. Following fertilization, supernumerary two pronuclear (2PN) oocytes were frozen. After thawing, 17 cycles of embryo transfer were carried out with a mean number of 2.7 embryos and a mean cumulative embryo score (CES) of 18.3 per transfer. The clinical pregnancy and implantation rates per transfer in these cycles (23.5 and 8.3% respectively) were comparable to those of fresh embryo transfers (35.7 and 12.7% respectively) with a mean number of 2.7 embryos and a mean CES of 28.7 per transfer. Abortion rates, although higher with cryopreserved 2PN oocytes were not significantly different. With this approach, cryopreservation of supernumerary 2PN oocytes can be used to improve the cumulative pregnancy rates in a severely defective spermatogenetic population. To our knowledge, these are the first pregnancies reported which have been obtained by the transfer of cryopreserved pronuclear oocytes obtained from ICSI using cryopreserved testicular spermatozoa.

Testicular sperm retrieval and cryopreservation prior to initiating ovarian stimulation as the first line approach in patients with non-obstructive azoospermia

The potency for fertilization and successful implantation was compared between fresh and cryopreserved testicular spermatozoa obtained from the same patient with non-obstructive azoospermia. Spermatozoa cryopreserved at the outset were also evaluated. Non-obstructive azoospermic men (n = 55) underwent testicular sperm extraction (TESE); mature spermatozoa were found in 33 (60%) of them. Of 57 intracytoplasmic sperm injection (ICSI) cycles in 25 patients, 15 used fresh spermatozoa (14 patients, group 1), 24 used the excess spermatozoa cryopreserved after 'fresh' ICSI (11 couples who did not conceive in the 'fresh' cycle, group 2) and 18 cycles used cryopreserved spermatozoa at the outset (11 other patients, group 3). Fertilization, cleavage, embryo quality, implantation and take home baby rates were not significantly different in groups 1 and 2, and 6/14 couples ultimately had healthy babies (42.8% cumulative take home baby rate per TESE). In group 3, neither the fertilization rate, embryo development, pregnancy nor implantation rates per embryo transfer were significantly different from groups 1 and 2. The cumulative delivery and ongoing pregnancy rate in this group was 36. 4%. Cryopreservation did not impair the availability of motile spermatozoa for ICSI. When immotile spermatozoa were injected, however, fertilization rate decreased dramatically. Since criteria for predicting the presence of spermatozoa in the testicular tissue of patients with non-obstructive azoospermia are inadequate, it is suggested that TESE be performed prior to initiating ovarian stimulation.

Freezing of testicular tissue as a minced suspension preserves sperm quality better than whole-biopsy freezing when glycerol is used as cryoprotectant

Frozen-thawed testicular spermatozoa have been used successfully for ICSI, especially in cases of obstructive azoospermia with normal spermatogenesis. Fewer attempts, however, have been made to check whether these rather immature spermatozoa, in a different environment with several other cell types present, have cryobiological requirements other than those of ejaculated spermatozoa. This is the reason why the freezing protocols and cryoprotectants (glycerol) used for freezing testicular tissue are based on experience with semen freezing. This study aimed to assess whether cryosurvival and/or motility was influenced by freezing of testicular tissue either as an intact biopsy or as a shredded tissue suspension, when glycerol was used as cryoprotectant. Freezing of testicular tissue as a suspension preserved motility (type B + C) significantly better than freezing of whole biopsies (9.2% vs. 4.0%). Similar observations have been made for vitality (39.3% vs. 25.4%). Centrifugation on 50% Percoll in order to remove the cryoprotectant resulted in a huge loss of spermatozoa (or late spermatids) and should therefore be especially avoided in cases of testicular failure. On the basis of these observations, mincing of the testicular biopsies before freezing may be advocated. Testicular spermatozoa seem to be better preserved when frozen in suspension, at least when slowly permeating glycerol is used as a cryoprotectant.

Frozen-thawed epididymal sperm is effective for intracytoplasmic sperm injection: implications for the urologist

OBJECTIVE

To evaluate the pregnancy potential of frozen-thawed surgically retrieved epididymal sperm when used with intracytoplasmic sperm injection (ICSI).

PATIENTS AND METHODS

From August 1994 to January 1997, 20 thawed samples of sperm from 19 patients, surgically retrieved and frozen after percutaneous or open epididymal aspiration, were used for ICSI. The results were compared with those obtained using fresh sperm obtained at the same procedure.

RESULTS

Of the specimens of surgically retrieved sperm which had been frozen, stored and thawed, 15 had sufficient motile sperm for use with ICSI. The fertilization, cleavage and pregnancy rates in those cycles were similar to the same couples' previous cycle using fresh sperm from the same collection and to the overall results in the NURTURE ICSI programme obtained with fresh epididymal sperm.

CONCLUSION

Scrotal exploration for diagnostic testicular biopsy and/or reconstructive surgery without having access to sperm-freezing and storage facilities could represent a lost opportunity for the patient.

Use of testicular sperm for the treatment of male infertility

Testicular biopsy has been widely used for the diagnosis of male infertility. Since the introduction of intracytoplasmic sperm injection (ICSI), sperm recovered from a testicular biopsy specimen can be successfully used for establishing pregnancies. Testicular spermatozoa may be recovered from testicular tissue in patients with excretory azoospermia but also in many patients with secretory azoospermia. In the latter patients spermatozoa may be recovered only after multiple excisional testicular biopsies, irrespective of follicle-stimulating hormone level, testicular size or medical history. Less invasive techniques such as percutaneous fine-needle aspiration have been introduced and may yield comparable success rates in patients with normal testicular function. The use of cryopreserved testicular spermatozoa may become an alternative to repeated surgery for obtaining testicular tissue for subsequent ICSI treatment cycles if larger series confirm the preliminary case reports. The introduction of the use of testicular spermatozoa for ICSI has raised new concerns because potentially genetically immature germ cells are being used from patients who may carry genetic defects causing their infertility problems.

Intracytoplasmic injection of fresh and cryopreserved testicular spermatozoa in patients with nonobstructive azoospermia--a comparative study

OBJECTIVE

To compare the outcome of intracytoplasmic sperm injection (ICSI) with fresh and frozen-thawed testicular spermatozoa in patients with nonobstructive azoospermia.

DESIGN

Retrospective analysis of consecutive ICSI cycles.

SETTING

In Vitro Fertilization Unit, Assaf Harofeh Medical Center.

PATIENT(S)

Eighteen with nonobstructive azoospermia in whom testicular sperm was found after testicular sperm extraction.

INTERVENTION(S)

Testicular sperm retrieval, cryopreservation, and ICSI with fresh or frozen-thawed testicular spermatozoa.

MAIN OUTCOME MEASURE(S)

Two-pronuclear fertilization; embryo cleavage rates, mean number of embryos transferred per cycle, and their relative quality, embryo implantation, clinical pregnancy, and ongoing pregnancy rates (PRs) per ET.

RESULT(S)

No statistically significant differences were noted in all parameters examined between ICSI cycles with fresh or cryopreserved testicular spermatozoa from the same nine patients and comparing all ICSI cycles performed; with fresh (25 cycles) and thawed (14 cycles) testicular spermatozoa, respectively: two-pronuclear fertilization, 47% versus 44%; embryo cleavage rates, 94% versus 89%; implantation rates, 9% versus 11%; and clinical PR, 26% versus 27%. The delivery or ongoing PR using fresh sperm was better (21% versus 9%), but the difference did not reach statistical significance. The cumulative clinical PRs and ongoing PRs per testicular sperm extraction procedure were 36% and 24%, respectively.

CONCLUSION(S)

Testicular sperm cryopreservation using a simple freezing protocol is promising in patients with nonobstructive azoospermia augmenting the overall success achieved after surgical sperm retrieval.

A new method for freezing testicular biopsy sperm: three pregnancies with sperm extracted from cryopreserved sections of seminiferous tubule

OBJECTIVE

To determine whether spermatozoa, located in the seminiferous tubules obtained by needle puncture testicular biopsy, could be cryopreserved successfully within the tubules and subsequently be used for in oocyte fertilization via intracytoplasmic sperm injection (ICSI) after the spermatozoa were removed from the thawed tubules.

DESIGN

Clinical case series.

SETTING

Private IVF unit.

PATIENT(S)

Six azoospermic patients (four obstructive, two maturation arrest).

MAIN OUTCOME MEASURE(S)

Survival rate of thawed spermatozoa, fertilization rate of oocytes after ICSI with spermatozoa extracted from thawed tubules and pregnancies.

RESULT(S)

All six patients had adequate motile spermatozoa extracted from the thawed tubule sections, and all patients achieved fertilization via ICSI with their partner's eggs. The fertilization rate was 46%, compared with 56% obtained in other previous patient cycles using fresh testicular spermatozoa. Three pregnancies resulted from five ETs.

CONCLUSION(S)

Cryopreservation and subsequent thawing of seminiferous tubules proved to be a simple and successful method for storage of testicular spermatozoa, reducing the need for repetitive testicular biopsies and increasing the likelihood of sperm availability on the day of oocyte retrieval.

Evaluation of seminiferous tubule scores obtained through testicular biopsy examinations of nonobstructive azoospermic men

OBJECTIVE

To evaluate the seminiferous tubules of nonobstructive azoospermic men, a modified version of the Johnsen score known as the seminiferous tubule score was used.

DESIGN

Retrospective clinical study.

SETTING

University-based urology center.

PATIENTS

One hundred twenty-eight infertile men with nonobstructive azoospermia who underwent open testicular biopsy.

INTERVENTION(S)

Categorization as follows of various seminiferous tubule characteristics according to the modified seminiferous tubule score parameters: [1] a total absence of cells within the seminiferous tubule, [2] Sertoli cell only, [3] a few spermatogonia, [4] many spermatogonia, [5] a few primary spermatocytes, [6] many primary spermatocytes, [7] a few secondary spermatocytes, [8] many secondary spermatocytes, [9] a few round spermatids, [10] many round spermatids, [11] a few late spermatids and/or spermatozoa, and [12] many late spermatids and/or spermatozoa.

MAIN OUTCOME MEASURE(S)

Seminiferous tubule score.

RESULT(S)

In terms of maximum seminiferous tubule score, scores of 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, and 12 corresponded with total patient numbers of 9, 90, 0, 0, 3, 10, 0, 0, 3, 1, 11, and 1, respectively.

CONCLUSION(S)

It was discovered that intracytoplasmic sperm injection (ICSI) of round spermatids could be performed in 3.1% of the patients in this study and that ICSI using late spermatids or spermatozoa could be performed in 9.4% of the patients in order to achieve fertilization.

Quality of frozen-thawed testicular sperm and its preclinical use for intracytoplasmic sperm injection into in vitro-matured germinal-vesicle stage oocytes

OBJECTIVE

To study the effects of cryopreservation on the quality of human testicular spermatozoa and the efficiency of intracytoplasmic sperm injection (ICSI) with frozen-thawed testicular sperm into metaphase II oocytes in vitro-matured from the germinal-vesicle stage oocyte.

DESIGN

Preclinical freezing study on supernumarary testicular spermatozoa after ICSI.

SETTING

Tertiary IVF center coupled with an institutional research environment.

PATIENT(S)

Twenty-nine patients undergoing excisional testicular biopsy for ICSI.

INTERVENTION(S)

Isolated testicular spermatozoa were cryopreserved and thawed; frozen-thawed motile testicular spermatozoa were microinjected.

MAIN OUTCOME MEASURE(S)

Prefreezing and post-thawing motility and viability, survival rate, fertilization rate, cleavage rate, and embryo quality after ICSI.

RESULT(S)

Mean percentage motility decreased from 21% before freezing to 6% after thawing. Vitality was impaired to a similar extent, decreasing from 68% to 22% (32% recovery rate). Injection of frozen-thawed testicular spermatozoa into in vitro-matured oocytes resulted in a fertilization rate of 50.9%. Cleavage rate was severely impaired. Half of the fertilized oocytes became arrested in the one-cell stage.

CONCLUSION(S)

Despite the low quality of the fresh testicular spermatozoa, a high percentage of prepared testicular sperm fractions showed survival and motility after the freezing and thawing process. Injection of frozen-thawed testicular sperm into matured oocytes resulted in fertilization rates comparable with these with fresh testicular sperm, but cleavage rates were severely impaired, which might be due to source of oocytes used for ICSI.