The relative viability of human spermatozoa from the vas deferens, epididymis and testis before and after cryopreservation

Testicular and epididymal spermatozoa are routinely used with in-vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI) to achieve pregnancies. In addition, excess cryopreserved spermatozoa can be thawed and used for ICSI. However, information on the recovery of epididymal and testicular spermatozoa after freeze-thaw is lacking. This is important to determine the feasibility of using previously cryopreserved aspirated spermatozoa for ICSI. We prospectively compared the viability of fresh and frozen-thawed spermatozoa from the vas deferens, epididymis and testicle by several measures. Testis spermatozoa were obtained from men with non-obstructive azoospermia (n = 5), epididymal spermatozoa from men with obstructive azoospermia (n = 8), and vasal spermatozoa from fertile men by vasal irrigation at vasectomy (n = 5). The viability of fresh spermatozoa was assessed by motility, two vital stains (carboxyfluorescein, 0.08 mg/ml and propidium iodide, 20 mg/ml) and the hypo-osmotic swelling assay (HOS; 100 mmol/l citrate and fructose). After cryopreservation, spermatozoa were thawed and all viability measures repeated. Although fresh vasal spermatozoa were the most motile, testicular spermatozoa exhibited similar, high viability (91 and 86% respectively) by vital stain. Spermatozoa from testis, epididymis and vas deferens survived cryopreservation equally well by vital stain, but not by motility. As a selection measure, the HOS assay identified significantly more viable epididymal and testicular spermatozoa than did motility in both fresh and frozen-thawed populations. It appears feasible to use frozen-thawed extracted spermatozoa for ICSI when motility and a selection measure such as the HOS assay are used. With fresh testis spermatozoa, selection methods may not be necessary prior to ICSI, as cell viability is high.     

Fertilization and pregnancy outcome with intracytoplasmic sperm injection for azoospermic men

The evident ability of the intracytoplasmic sperm injection (ICSI) procedure to achieve high fertilization and pregnancy rates regardless of semen characteristics has induced its application with spermatozoa surgically retrieved from azoospermic men. Here, ICSI outcome was analysed in 308 cases according to the cause of azoospermia; four additional cycles were with cases of necrozoospermia. All couples were genetically counselled and appropriately screened. Spermatozoa were retrieved by microsurgical epididymal aspiration or from testicular biopsies. Epididymal obstructions were considered congenital (n = 138) or acquired (n = 103), based on the aetiology. Testicular sperm cases were assessed according to the presence (n = 14) or absence (n = 53) of reproductive tract obstruction. The fertilization rate using fresh or cryopreserved epididymal spermatozoa was 72.4% of 911 eggs for acquired obstructions, and 73.1% of 1524 eggs for congenital cases; with clinical pregnancy rates of 48.5% (50/103) and 61.6% (85/138) respectively. Spermatozoa from testicular biopsies fertilized 57.0% of 533 eggs in non-obstructive cases compared to 80.5% of 118 eggs (P = 0.0001) in obstructive azoospermia. The clinical pregnancy rate was 49.1% (26/53) for non-obstructive cases and 57.1% (8/14) for testicular spermatozoa obtained in obstructive azoospermia, including three established with frozen-thawed testicular spermatozoa. In cases of obstructive azoospermia, fertilization and pregnancy rates with epididymal spermatozoa were higher than those achieved using spermatozoa obtained from the testes of men with non-obstructive azoospermia.     

Reproductive capacity of spermatozoa from men with testicular failure.

Controversial reports have been published about the influence of sperm source and of the underlying testicular pathology on success rates of intracytoplasmic sperm injection (ICSI). In this controlled study, ICSI treatment cycles with testicular spermatozoa from men with obstructive and non-obstructive azoospermia were compared with ICSI ejaculated sperm cycles with semen parameters < or = 5 x 10(6)/ml and < or = 10% progressive motility. The control cases were matched for female age, rank of trial, female basal follicle-stimulating hormone serum concentrations and close proximity to the study group's procedure. The fertilization, cleavage, pregnancy and abortion rates were similar in matched groups irrespective of the type of azoospermia. However, the implantation rate in the non-obstructive azoospermic patient group was significantly lower than that in the matched ejaculated sperm group (13.4% versus 26%, P = 0.05). On the other hand, no impairment of the implantation rate was observed in the obstructive azoospermic patient group. These data show that testicular pathology has a negative impact on reproductive performance of testicular spermatozoa, resulting in a decreased implantation potential without any apparent effect on fertilization and early preimplantation development.     

The outcome of intracytoplasmic injection of fresh and cryopreserved epididymal spermatozoa from patients with obstructive azoospermia--a comparative study

The aim of our study was to compare the outcome of intracytoplasmic sperm injection (ICSI) with fresh and frozen-thawed epididymal spermatozoa retrieved by percutaneous epididymal sperm aspiration (PESA) or microepididymal sperm aspiration (MESA) from patients with obstructive azoospermia. A retrospective analysis of consecutive ICSI cycles was performed, comparing the outcome in 24 patients with obstructive azoospermia undergoing surgical sperm aspiration by MESA (7 cycles) or PESA (17 cycles). In 23 of 24 patients, excess spermatozoa were cryopreserved. Following thawing, 21 ICSI cycles were performed (11 cycles after MESA, 10 after PESA). No statistically significant differences were noted in all parameters examined in ICSI cycles with fresh or cryopreserved spermatozoa from the same patients. Comparing all ICSI cycles with fresh and frozen-thawed epididymal spermatozoa, the rates of two-pronuclear fertilization (56% versus 53%), embryo cleavage (90% versus 86%), implantation (10% versus 14%), clinical pregnancy per embryo transfer (32% versus 37%) and delivery/ongoing pregnancy rate (27% versus 26%) were not statistically different. The cumulative ongoing pregnancy rate per sperm retrieval procedure was 46%, respectively. We conclude that the clinical outcome of ICSI with fresh and frozen-thawed spermatozoa after retrieval by PESA was similar to that by MESA. Epididymal sperm cryopreservation in patients with obstructive azoospermia is feasible and efficient using a simple freezing protocol and should be offered to optimize the yield of pregnancies achieved following such procedures.      

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.     

Assisted reproduction with in-vitro-cultured testicular spermatozoa in cases of severe germ cell apoptosis: a pilot study.

BACKGROUND: Apoptosis-related cell damage is known to compromise success rates of assisted reproduction with ejaculated spermatozoa. This study was undertaken to determine whether the frequency of apoptosis-related cell damage and reproductive performance of testicular spermatozoa from men with non-obstructive azoospermia can be improved by in-vitro culture. METHODS: Testicular tissue samples were cultured for 2 days in the presence of 50 IU/l FSH and 1 micromol/l testosterone. The frequency of spermatozoa showing DNA strand breakage and plasma membrane phosphatidylserine externalization was compared in before-culture and after-culture samples. The after-culture samples were used in assisted reproduction attempts. RESULTS: In a group of 11 azoospermic patients with at least two previous intracytoplasmic sperm injection (ICSI) failures, the incidence of DNA strand breakage was high in living testicular spermatozoa from before-culture samples, but significantly lower in after-culture samples (96 versus 30%, P < 0.001). The same applied to the incidence of phosphatidylserine externalization in the motile sperm subpopulation from the before-culture and after-culture samples (83 versus 6%, P < 0.001). Seven ongoing clinical pregnancies (six with fresh embryos and one with cryopreserved embryos) were established. CONCLUSIONS: Severe testicular sperm apoptosis may become a new indication for testicular tissue in-vitro culture before ICSI.     

Intracytoplasmic sperm injection in obstructive and non-obstructive azoospermia

We compared the results of intracytoplasmic sperm injection (ICSI) in: (i) obstructive versus non-obstructive azoospermia, (ii) obstructive azoospermia using epididymal versus testicular spermatozoa and (iii) acquired versus congenital obstructive azoospermia due to congenital absence of the vas deferens (CAVD). A retrospective analysis was done of 241 consecutive ICSI cycles done in 103 patients with non- obstructive azoospermia and 119 patients with obstructive azoospermia. In the obstructive group, 135 ICSI cycles were performed. Epididymal spermatozoa were used in 44 cycles and testicular spermatozoa in 91 cycles. In the non-obstructive group, 106 cycles were performed. The fertilization and pregnancy per cycle rates were 59.5 and 27.3% respectively using epididymal spermatozoa, 54.4 and 31.9% respectively using testicular spermatozoa in obstructive cases, and 39 and 11.3% respectively in non-obstructive cases. The fertilization and pregnancy per cycle rates were 56.6 and 37% respectively in acquired obstructive cases, and 55.2 and 20.4% respectively in CAVD. In conclusion, ICSI using spermatozoa from patients with acquired obstructive azoospermia resulted in significantly higher fertilization and pregnancy rates as compared to CAVD and non-obstructive cases.      

Pregnancies after intracytoplasmic sperm injection with cryopreserved testicular spermatozoa

In 25 patients (14 suffering from obstructive azoospermia, sixfrom non-obstructive azoospermia, three from astheno-azoospermiaand two from absence of ejaculation) spermatozoa were extractedfrom testicular biopsies. Intracytoplasmic sperm injection (ICSI)with fresh testicular spermatozoa was performed in 18 cases;spermatozoa in excess were cryopreserved in pills. No pregnancieswere achieved. In the remaining seven patients, testicular spermatozoawere retrieved and cryopreserved during a diagnostic testicularbiopsy. After thawing, sperm motility was assessed in 17 cases(68%), and 18 ICSI with cryopreserved testicular spermatozoawere performed. The mean two-pronuclear (2PN) fertilizationrate was 59%, the mean cleavage rate was 92%, and six clinicalpregnancies were achieved, all of them still ongoing (pregnancyrate 33%). A comparison of the results of ICSI carried out withfresh or cryopreserved testicular spermatozoa showed that themean 2PN fertilization rates per cycle (53 compared with 55%),mean cleavage rates per cycle (99 compared with 96%) and embryoquality were not significantly different In conclusion, cryopreservationof testicular spermatozoa is feasible, even in patients withnon-obstructive azoospermia, and the results of ICSI with frozen-thawedtesticular spermatozoa are similar to those obtained using freshtesticular spermatozoa. Cryopreservation of testicular spermatozoamay avoid repetition of testicular biopsies to retrieve spermatozoafor successive ICSI cycles in patients in whom the only sourceof motile spermatozoa is the testicle.     

Surgical sperm recovery for intracytoplasmic sperm injection: which method is to be preferred?

Different methods for recovering epididymal or testicular spermatozoa have been described and each has its drawbacks and advantages. Percutaneous aspiration of the testis may be the method of choice in cases of irreparable obstructive azoospermia. Using a 21-gauge needle, spermatozoa may be recovered in 96 % of patients. More patients undergoing fine-needle aspiration experienced less pain than expected as compared with those undergoing open biopsy. Microsurgical epididymal sperm aspiration (MESA) is the preferred method in patients with an incomplete work-up because, if indicated, a vasoepididymostomy can be performed concomitantly with a full scrotal exploration. In azoospermic patients with testicular failure, the sperm recovery rate, i.e. the chance of finding at least one spermatozoon, is around 50% after multiple open biopsies. However, the fertilization rates after intracytoplasmic sperm injection (ICSI) are significantly lower than in men with normal spermatogenesis, and complete fertilization failure may occur more frequently. Although the combination of testicular sperm extraction (TESE) and ICSI may be the sole treatment available for infertility because of non-obstructive azoospermia, the overall success rate is limited and ongoing pregnancies are obtained in < or =20% of ICSI cycles. In patients with incomplete Sertoli cell-only syndrome, testicular damage may be limited by use of a selective microsurgical approach; less invasive methods such as fine-needle aspiration are not useful in these patients. Of 14 patients with primary testicular failure as proven by histopathology, only in one case (7.1%) were spermatozoa recovered by multiple aspirations, while in nine cases (64.3%) spermatozoa were recovered by open biopsy. Although the pregnancy rates reported after ICSI with frozen-thawed testicular spermatozoa from patients with primary testicular failure are relatively low, the recovery of testicular spermatozoa by open biopsy followed by cryopreservation may be the method of choice by which to prevent repeat surgery and pointless ovarian stimulation in the female partner.     

Comparison of the fertilizing capability of spermatozoa from ejaculates, epididymal aspirates and testicular biopsies using intracytoplasmic sperm injection

A prospective study was carried out to compare the fertilizing capability and pregnancy outcome following intracytoplasmic sperm injection (ICSI) using spermatozoa obtained from ejaculates, or surgically from epididymis or seminiferous tubules. A total of 77 ICSI cycles (one per patient) was included. In all, 28 patients had severe oligoasthenoteratozoospermia, 19 patients had obstructive azoospermia and 30 patients had non-obstructive azoospermia. The main outcome measures were fertilization rate per injected metaphase II oocyte and the clinical pregnancy rate per embryo transferred back to the female recipients. In patients with severe oligoasthenoteratozoospermia, the fertilization and pregnancy rates were 79 and 25 %. In patients with obstructive azoospermia, for whom epididymal spermatozoa were used, these were 75 and 28%, and in the non-obstructive group for which testicular spermatozoa were used for injection, they were 69 and 21% respectively. These rates were not significantly different in the three groups (P = 0.85 and P = 0.14 respectively), suggesting that spermatozoa from the ejaculates and epididymal or testicular biopsies are able to fertilize equally by using ICSI. Live birth per embryo transfer was significantly reduced in patients with non-obstructive azoospermia compared to the other two groups. The high abortion rate (50%) in the group in which testicular spermatozoa were used raises doubts about the developmental competence of such embryos.      

Diagnostic epididymal and testicular sperm recovery and genetic aspects in azoospermic men.

Various procedures for sperm recovery in azoospermic men have been described, from open testicular biopsy to simple needle aspiration from the epididymis and the testis. Fifty-one obstructive and 86 non-obstructive azoospermic men were treated to compare the recovery of spermatozoa obtained by percutaneous aspiration from the epididymis (PESA) and aspiration/extraction from the testis (TESA, TESE) with histopathology. If TESA failed, the work up proceeded with TESE. All patients were karyotyped. Spermatozoa were recovered by PESA or TESA in all obstructive men (51/51 patients). In 22 out of 86 patients with non-obstructive azoospermia, testicular spermatozoa could be successfully recovered by TESA. In five additional patients TESE was successful in recovering spermatozoa where TESA had failed. In 43 patients, neither TESA nor TESE was successful. Sixteen patients chose not to proceed with TESE. Seven out of 86 patients had an abnormal karyotype in the non-obstructive group (8%), none in the obstructive group. In the non-obstructive patient group testicular histopathology showed hypospermatogenesis, incomplete maturation arrest and germ cell aplasia with focal spermatogenesis in cases where spermatozoa were recovered and complete germ cell aplasia, complete maturation arrest and fibrosis in cases where no spermatozoa were found. Spermatozoa were recovered by PESA or TESA from all patients with obstructive azoospermia and from approximately 40% of patients with non-obstructive azoospermia by TESA or TESE. Retrieval of viable spermatozoa in the infertility work-up was highly predictable for sperm recovery in subsequent ICSI cycles. TESA performed under local anaesthesia seems almost as effective as more invasive procedures in recovering testicular spermatozoa, both in obstructive and non-obstructive azoospermic men.     

Fertilization, pregnancy and embryo implantation rates after ICSI in cases of obstructive and non-obstructive azoospermia

The aetiology of azoospermia can be grossly divided into obstructive and non-obstructive causes. Although in both cases testicular spermatozoa can be used to treat male fertility, it is not well established whether success rates following intracytoplasmic sperm injection (ICSI) are comparable. Therefore, a retrospective analysis of fertilization, pregnancy and embryo implantation rates was performed following ICSI with testicular spermatozoa in obstructive or non-obstructive azoospermia. In total, 193 ICSI cycles were carried out with freshly retrieved testicular spermatozoa; in 139 cases of obstructive and 54 cases of non-obstructive azoospermia. The fertilization rate after ICSI with testicular spermatozoa in non-obstructive azoospermia was significantly lower than in obstructive azoospermia (67.8% versus 74.5%; P = 0.0167). Within the non-obstructive group, the fertilization rate in the group of maturation arrest (47.0%) was significantly lower than in case of Sertoli cell-only (SCO) syndrome (71.2%) or germ cell hypoplasia (79. 5%). Embryo quality on day 2 after ICSI was similar for all groups. Pregnancy rates per transfer between obstructive (36.8%) and non-obstructive groups (36.7%) were similar. In cases of maturation arrest the pregnancy rate per transfer was lowest (20.0%) although not significantly different from SCO syndrome or hypoplasia groups. Embryo implantation rates were not different between the obstructive (19.6%) and non-obstructive groups (25.8%), and were lowest in cases of germ cell hypoplasia (15.8%). This retrospective analysis shows that although fertilization rate after ICSI with testicular spermatozoa in non-obstructive azoospermia is significantly lower than in obstructive azoospermia, pregnancy and embryo implantation rates are similar.     

The results of 154 ICSI cycles using surgically retrieved sperm from azoospermic men

BACKGROUND: The effects of source of sperm, aetiology and sperm cryopreservation on ICSI cycles in azoospermic men were evaluated. The effect of aetiology of azoospermia on embryo development was also assessed. METHODS: This study was a retrospective analysis of 154 cycles (91 couples) using surgically retrieved sperm. Outcome measures were fertilization rate (FR), implantation rate (IR), and clinical pregnancy rate (CPR) and livebirth rate (LBR) per transfer. RESULTS: Our data demonstrated similar outcome between the use of epididymal or testicular sperm in men with obstructive azoospermic (OA). FR and IR were significantly lower (P < 0.05) using sperm from men with non-obstructive azoospermic (NOA), but although pregnancy outcome appeared lower, this did not reach statistical significance (P = 0.08). Cryopreservation of epididiymal sperm did not alter outcome, but the use of frozen-thawed testicular sperm did demonstrate a lower FR, with no statistical difference in IR or pregnancy outcome. Embryos derived from NOA sperm had impaired development beyond day 2 post-oocyte retrieval (OA, 44% <5 cell; NOA, 71% <5 cell; P = 0.002). CONCLUSIONS: The use of sperm from men with NOA significantly affects fertilization and implantation in ICSI cycles. The use of frozen-thawed testicular sperm affects fertilization rate without significantly altering pregnancy outcome. The use of such data on which to base clinical decisions needs to be supported by the meta-analyses of previous reports.     

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.     

In-vitro culture of spermatozoa induces motility and increases implantation and pregnancy rates after testicular sperm extraction and intracytoplasmic sperm injection.

The aim of this study was to determine the effect of 24-h in-vitro culture of testicular spermatozoa in recombinant follicle stimulating hormone (recFSH) supplemented medium versus simple medium on sperm motility, and to analyse the outcome of intracytoplasmic sperm injection (ICSI) of such spermatozoa. A total of 143 positive testicular sperm extraction procedures in men with non-obstructive azoospermia was evaluated prospectively. Extracted testicular tissue samples were randomized to be cultured in vitro for 24 h in simple medium or recFSH supplemented media. ICSI was performed with spermatozoa cultured in recFSH (n = 73) or in simple medium (n = 70). Sperm motility following in-vitro culture, embryo quality after ICSI, and implantation and pregnancy rates were assessed. Of the 898 MII oocytes available in the recFSH group, 646 (71.9%) were injected with spermatozoa showing either twitching or progressive motility. However, only 29.1% of the oocytes in the simple medium group (245/841) were injected with motile spermatozoa (P < 0.05). Fertilization rate (68.8 versus 42.1%), implantation rate per embryo (20.1 versus 13.2%), and clinical pregnancy rate (47. 9 versus 30%) were significantly increased in the recFSH group compared with the simple medium group respectively (P < 0.05). In conclusion, in-vitro culture with recFSH appears to increase the motility of testicular spermatozoa, thus increasing the success of ICSI.     

Outcome of testicular sperm recovery and ICSI in patients with non-obstructive azoospermia with a history of orchidopexy

BACKGROUND: Little is known about sperm recovery and ICSI using testicular sperm from men with non-obstructive azoospermia who had a previous orchidopexy. We therefore studied the sperm recovery in this subgroup and evaluated clinical parameters predicting successful sperm retrieval and the outcome of ICSI. METHODS: A total of 79 non-obstructive azoospermic men with a history of orchidopexy underwent a sperm recovery procedure. The predictive value of clinical parameters such as age at sperm retrieval, age at orchidopexy, testicular volume, FSH, FSH/LH ratio, testosterone and androgen sensitivity index (LH x testosterone) for successful testicular sperm retrieval was evaluated using receiver operating characteristics (ROC) curve analysis. A comparison between 64 ICSI cycles performed in these couples and 92 cycles performed in couples in which the men had an unexplained non-obstructive azoospermia was carried out. RESULTS: Testicular spermatozoa were recovered in 41 patients (52%). The mean age at orchidopexy of the patients with a positive sperm recovery was 10.6 years [95% confidence interval (CI) 7.3-13.8] versus 15.5 years (95% CI 11.3-19.8) for those where no spermatozoa were found. The mean testicular volume of the largest testis of patients with spermatozoa found was 10 ml (95% CI 8.3-11.9) versus 8.5 ml (95% CI 5.8-11.1) in patients with no spermatozoa found. The mean FSH and testosterone value for patients with successful and unsuccessful sperm recovery, respectively, was 24.1 IU/l (95% CI 17.9-30.3) and 4.4 ng/ml (95% CI 3.7-5.1) versus 28.8 IU/l (95% CI 19.4-38.2) and 3.4 ng/ml (95% CI 2.2-4.5). All clinical and biological parameters examined failed to predict the outcome of the testicular sperm extraction. No differences were observed between the orchidopexy and unexplained group for the number of oocytes retrieved, fertilization rate, embryo quality, pregnancy rate and implantation rate. CONCLUSIONS: As in the population of men with non-obstructive azoospermia, the sperm recovery rate for patients with a history of orchidopexy is approximately 50% and there are currently no clinical parameters predicting successful sperm retrieval in this subpopulation of patients. The outcome of the ICSI cycles is comparable with that in the population of men with non-obstructive azoospermia.     

Reproductive capacity of round spermatids compared with mature spermatozoa in a population of azoospermic men

The present study aims to evaluate the injection of testicular round spermatids from patients with complete failure of spermiogenesis compared with that of mature epididymal and testicular spermatozoa. Over a period of 8 months, 188 azoospermic patients were evaluated with a view to their inclusion in our intracytoplasmic sperm injection (ICSI) programme. All patients had had a previous testicular biopsy; 38 had pure obstructive azoospermia, while 150 had non-obstructive azoospermia. Mature spermatozoa were found in 93 patients, whereas spermatozoa were entirely absent, with a predominance of round spermatids in 87. In eight patients, spermatids could not be found and therefore their cycles were cancelled. There was an early appearance of the two pronuclei stage in the round spermatid group compared with the mature spermatozoa group of patients (10.2 and 16 h respectively). The fertilization rate was also significantly lower (P = 0.00001) in the round spermatid group. The numbers of embryos developed and of embryo transfers in the round spermatid injection group were significantly lower compared with the mature spermatozoa injection group (P = 0.05 and 0.0001 respectively). No pregnancies resulted from round spermatid injection, while 18 pregnancies were achieved from the injection of mature spermatozoa. In conclusion, injection of round spermatids from patients with complete failure of spermiogenesis resulted in a significantly lower fertilization rate and a higher developmental arrest compared with injection of mature spermatozoa. With no pregnancies achieved, one may question the unusual variability of reported success rates and stress the need for further research in order to improve the outcome of this novel technique.     

Blastocyst transfer following intracytoplasmic injection of ejaculated, epididymal or testicular spermatozoa

Recent studies indicate a strong paternal influence on embryo development and progression of the embryo to the blastocyst stage. The aim of this study was to compare, during extended culture, the in-vitro development of embryos resulting from intracytoplasmic sperm injection (ICSI) of ejaculated spermatozoa (group 1, n = 347), epididymal (group 2, n = 22) or testicular (group 3, n = 18) spermatozoa from obstructive azoospermic and testicular spermatozoa from non-obstructive azoospermic (group 4, n = 31) subjects. Fertilization and blastocyst formation rates were significantly lower in group 4 (P < 0.05). The incidence of expanded and hatching blastocysts was significantly lower in group 4 (P < 0.05). Overall in 93.2% ejaculate ICSI cycles, blastocysts were transferred on day 5. This was significantly higher than the 62% day 5 transfers in the non-obstructive azoospermic group (P < 0.05). Implantation rate per embryo was significantly higher in the ejaculate ICSI group compared with the other groups (P < 0.05). Clinical pregnancy per transfer was similar between groups; however, significantly fewer multiple pregnancies were encountered in the non-obstructive azoospermic group (P < 0.01). In conclusion, the source of the spermatozoa, most likely to be indicative of the severity of spermatogenic disorder, affects the rate of blastocyst formation and blastocyst implantation. Spermatozoa from non-obstructive azoospermic subjects, when utilized for ICSI, result in embryos that progress to the blastocyst stage at a lower and slower rate and implant less efficiently.     

Multiple testicular sampling in non-obstructive azoospermia--is it necessary?

Spermatogenesis may be focal in non-obstructive azoospermia. The present study was conducted to determine whether the performance of multiple, rather than a single testicular sample contributes to obtaining spermatozoa in amounts sufficient for fertilization and cryopreservation in non-obstructive, azoospermic patients. Furthermore, the aim was to clarify the significance of location for retrieval from the testis in such cases. Three biopsies were taken from identical locations in 55 testes of 29 men with non-obstructive azoospermia: (i) the rete testis region, ii) the midline, and (iii) the proximal region of the testis. When sperm cells were detected, they were used for intracytoplasmic sperm injection (ICSI), and the remainder were then cryopreserved in as many aliquots as possible (adjusted for ICSI procedure). Spermatozoa were found in 28 testes (50.9%) of 18 men (62.1%). In the testes from which spermatozoa were obtained, they were present in three, two or one locations in 15 (53.6%), five (17.9%) and eight (28.6%) cases respectively. The possibility of finding spermatozoa was not influenced by the location in the testis. Multiple testicular sperm extraction is recommended in cases of non-obstructive azoospermia, since it may enhance diagnostic accuracy of absolute testicular failure and increase the number of sperm cells retrieved.