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.     

Fertilization, pregnancy and embryo implantation rates after ICSI with fresh or frozen-thawed testicular spermatozoa

This study aimed to determine whether fertilization and implantation rates after intracytoplasmic sperm injection (ICSI) with fresh or frozen-thawed testicular spermatozoa were comparable. Between 1 January 1996 and 31 December 1996, 65 ICSI cycles with testicular spermatozoa and 35 cycles with frozen-thawed testicular spermatozoa were carried out. In 50 out of 65 ICSI cycles, testicular spermatozoa could be retrieved and in 34 out of 35 cycles carried out with frozen-thawed testicular spermatozoa, motile spermatozoa could be recovered. The fertilization rate after ICSI with frozen-thawed testicular spermatozoa was significantly lower (71.1%; P < or = 0.008) than with fresh testicular spermatozoa (79.3%). The pregnancy rate was similar for both groups (38.2 and 26.5 %). The implantation rate per transferred embryo, however, was significantly lower in the frozen-thawed rather than in the fresh testicular sperm group (9.1 versus 24.6%; P = 0.001). The live birth rate per transferred embryo was also higher in the group in which fresh testicular spermatozoa were used (18.8 versus 7.9% P = 0.043). This retrospective study shows that is possible to achieve a high fertilization rate after ICSI with both fresh and frozen-thawed testicular spermatozoa but implantation and live birth rates per transferred embryo, however, are significantly lower after ICSI with frozen-thawed than with fresh testicular spermatozoa.      

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.     

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.     

A comparison of ICSI outcomes with fresh and cryopreserved epididymal spermatozoa from the same couples

The published experience with frozen-thawed epididymal spermatozoa and intracytoplasmic sperm injection (ICSI) suggests that fertilization and pregnancy success rates are comparable to those achieved with freshly retrieved spermatozoa. However, no study has exactly compared clinical outcomes between the two IVF/ICSI cycles in the same couples. To formally address this issue, we assessed ICSI outcomes in couples each of whom had had two IVF/ICSI cycles: one using fresh and the second using frozen-thawed epididymal spermatozoa obtained from a single aspiration procedure. From a pool of 101 consecutive patients undergoing IVF/ICSI with epididymal spermatozoa, 19 couples initially used fresh epididymal spermatozoa and subsequently underwent a second IVF/ICSI procedure with frozen-thawed spermatozoa from the same aspiration. Normal (2PN) oocyte fertilization rates, embryo quality and pregnancy rates were compared between the two IVF/ICSI cycles for each couple. In the fresh epididymal sperm group, 58.4% of the injected oocytes fertilized normally compared with 62.0% of the injected oocytes in the frozen-thawed epididymal sperm group, revealing no statistically significant difference. Graded embryo quality also did not differ significantly between the paired IVF/ICSI cycles. The clinical pregnancy rates were 31.6% (6/19) and 36.8% (7/19) in the first and second cycles respectively. All but one pregnancy were singletons. In summary, this study provides strong evidence to support the notion that motile, cryopreserved and thawed epididymal spermatozoa are equal to freshly retrieved spermatozoa for ICSI in couples with obstructive azoospermia.     

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.      

Testicular biopty gun needle biopsy in collecting spermatozoa for intracytoplasmic injection, cryopreservation and histology.

Using testicular spermatozoa from either open biopsy (29 cycles) or biopty gun needle biopsy (49 cycles), a total of 81 intracytoplasmic sperm injection (ICSI) cycles among 57 couples were carried out from January, 1994 to September, 1997. In six cycles, no spermatozoa were obtained, and in three cycles spermatozoa from both needle and open biopsies were used. The fertilization (37% after open and 41% after needle biopsy) and pregnancy rates (29% per embryo transfer compared with 16% per embryo transfer) were similar after both open and needle biopsies. Five pregnancies were achieved among the 14 couples with non-obstructive azoospermia of the male partner, four of these after needle biopsy. It was possible to use cryopreserved testicular spermatozoa after both needle and open biopsies, and one pregnancy started after using cryopreserved testicular spermatozoa in both groups. Histological needle biopsy was carried out in 62 cases, and they were all diagnostic, giving 15-20 cross-sections of seminiferous tubuli per biopsy. Testicular needle biopsy using a 14 gauge biopsy needle gave a sufficient amount of tissue and spermatozoa for ICSI, cryopreservation and histology, even in non-obstructive azoospermia. This technique is simpler and cheaper than open biopsy and, hence, it can be regarded as the optimal method for the retrieval of testicular spermatozoa.     

Full-term delivery following intracytoplasmic sperm injection with frozen-thawed immotile testicular spermatozoa

We present one of the very few deliveries occurring following intracytoplasmic sperm injection of thawed immotile testicular spermatozoa from a testicular biopsy of a man with bilateral congenital absence of the vas deferens. A first attempt in the 33 year old woman with fresh testicular biopsy extracted spermatozoa was unsuccessful. The supernumerary spermatozoa were cryopreserved for later use. After thawing, testicular spermatozoa were immotile. From 11 intact oocytes injected with frozen-thawed immotile testicular spermatozoa, a two pronuclear fertilization rate of 27% and a cleavage rate of 100% were obtained. A total of three embryos was transferred resulting in a singleton pregnancy and the birth of a normal female baby.      

睾丸精子冻融后行卵胞浆内单精子注射术在无精子症患者中的临床应用

目的探讨对无精子症患者实施睾丸精子经冷冻复苏后行卵胞浆内单精子注射术（ICSI）的临床效果。方法回顾性分析了既往在我中心有冷冻睾丸精子的34个ICSI周期,评估其冷冻精子复苏、卵子受精、卵裂、可移植胚胎、优质胚胎、临床妊娠及其分娩情况。结果 34个拟定复苏冷冻睾丸精子的周期精子复苏均获得成功,受精率为76.9%（249/324）,2PN受精率69.7%（226/324）,卵裂率98.8%（246/249）,可利用胚胎率84.2%（207/246）,优质胚胎率46.3%（114/246）;所有周期均有胚胎移植;34个周期中行新鲜胚胎移植30个,种植率为34.4%（21/61）,临床妊娠17例（临床妊娠率56.7%）包括13例单胎和4例双胎,其中1例单胎妊娠流产（流产率为5.9%）。目前,有14个周期已经出生了18个健康婴儿（10个男婴,8个女婴）未发现先天缺陷儿,另2例单胎继续妊娠中（32＋w,29＋w）。结论睾丸精子经冷冻后有很好的复苏率,结合ICSI受精可以得到较好的临床结局。     

Outcome of in-vitro culture of fresh and frozen-thawed human testicular spermatozoa

The effect of in-vitro culture on the motility and morphology of fresh and frozen-thawed human testicular spermatozoa obtained from obstructive azoospermic patients and on the motility of testicular spermatozoa obtained from non-obstructive azoospermic patients was evaluated. The outcome of intracytoplasmic sperm injection (ICSI) with fresh and frozen-thawed human testicular spermatozoa was studied. The results showed that significant improvement of sperm morphology and motility was observed in culture of fresh (n = 17) and frozen-thawed (n = 15) testicular sperm samples obtained from patients with obstructive azoospermia. The motility of cultured testicular spermatozoa reached a peak at 72 h without the need for special media. In six of 20 samples obtained from patients with non-obstructive azoospermia, improvement of sperm motility was observed. When only non-motile testicular spermatozoa were cultured, they all remained non-motile (n = 9). In patients with obstructive azoospermia, fertilization rates of 80 and 81% were obtained using ICSI with fresh and frozen-thawed testicular spermatozoa respectively. Clinical pregnancies were observed in four out of nine patients with fresh testicular spermatozoa and two out of five patients after using frozen-thawed spermatozoa. When fresh testicular spermatozoa obtained from patients with non-obstructive azoospermia were used for ICSI, the fertilization rate was 68% and two out of seven patients achieved clinical pregnancies. In conclusion, the morphology and motility of fresh and frozen-thawed testicular spermatozoa in patients with obstructive azoospermia can be significantly improved after in-vitro culture. The outcome of in-vitro culture of testicular spermatozoa in patients with non-obstructive azoospermia is unpredictable. In-vitro culture of non-motile testicular spermatozoa is not successful so far. The outcome of ICSI with fresh and with frozen-thawed testicular spermatozoa was similar.      

Different fertilization rates between immotile testicular spermatozoa and immotile ejaculated spermatozoa for ICSI in men with Kartagener's syndrome: case reports

We report two cases of infertility treatment in couples where males suffered from Kartagener's syndrome (KS) and a total absence of motile sperm in the ejaculate. A total of three ICSI cycles was carried out. In all cycles, viable ejaculated or testicular spermatozoa were selected using the hypo-osmotic swelling (HOS) test. Case 1: In the first ICSI cycle total fertilization failure occurred after using ejaculated spermatozoa. In the following cycle testicular spermatozoa were used for ICSI, resulting in 75% fertilized oocytes and a pregnancy. Case 2: In the same ICSI cycle 50% of the oocytes were injected with ejaculated and 50% with testicular spermatozoa. The fertilization rates were 44 and 56% respectively and high quality embryos were achieved in both groups. One single embryo derived from testicular sperm was transferred with a resulting singleton pregnancy. In conclusion, testicular sperm for ICSI seem to have reliable fertilization capacity in men with KS, while ejaculated sperm, even if tested viable, seem more unpredictable. HOS test for selection of viable sperm for ICSI is recommended when ejaculated as well as testicular sperm are used for ICSI.     

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.     

In-vitro fertilization treatment for severe male factor: the fertilization potential of immotile spermatozoa obtained by testicular extraction

A retrospective analysis in 50 couples of 53 cycles of intracytoplasmic sperm injection (ICSI) with immotile spermatozoa from testicular-retrieved spermatozoa was performed to evaluate whether total immotile spermatozoa achieved after testicular sperm extraction could fertilize ova and result in pregnancies. We assessed the efficacy of ICSI with totally immotile testicular spermatozoa extracted from the testes of azoospermic patients with severe spermatogenic failure (group 1) and compared these results with those from spermatozoa which were recovered after several hours of incubation and were motile (group 2) at the time of injection. In 19 cycles, only totally immotile spermatozoa were injected at the time of ICSI. For the remaining 34 cycles, at least one motile spermatozoon was found for injection. The oocyte fertilization rates were 51% for group 1 and 62% for group 2 (P < 0.02). Eighteen of 19 cycles in group 1 (90%) and all 34 (100%) cycles in group 2 had embryos for replacement. The mean number of embryos per cycle was 5.2 +/- 0.8 and 7.5 +/- 0.9 in groups 1 and 2 respectively; this and the embryo quality (cumulative embryo scoring = 40 +/- 8 for group 1 and 50 +/- 7 for group 2), and clinical pregnancy rates (15.8% per oocyte retrieval in group 1 and 23.5% in group 2) were not significantly different between groups. Fertilization, cleavage and pregnancy can be achieved with intracytoplasmic testicular sperm injection from patients with immotile spermatozoa, at levels comparable with those of ICSI using motile spermatozoa.     

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.      

Clinical use of a pronuclear stage score following intracytoplasmic sperm injection: impact on pregnancy rates under the conditions of the German embryo protection law

The German embryo protection law does not allow embryo selection, but only selection of pronuclear stage (PN) oocytes. Only as many PN oocytes are allowed to be selected as are planned to be transferred. Therefore, a clinically applicable score to assess the quality of PN oocytes would be helpful. A recently published score was used under the conditions of the German embryo protection law in 74 non-selected, consecutive intracytoplasmic sperm injection cycles. Only criteria which could be evaluated at the PN stage were included, i.e. not criteria which could only be assessed after pronuclear membrane breakdown or the first cleavage division. Supernumerary PN oocytes were cryopreserved after selection. A mean PN score of <13 (sum of scores of all selected PN oocytes/number of selected PN oocytes) led to a pregnancy rate of 4%, a mean PN score of > or =13 to a pregnancy rate of 22%. Embryo morphology and cumulative PN were correlated (r = 0.52, P < 0.05). The negative predictive value was 92% at a threshold of 13 for the mean PN score. The use of this and perhaps additional scoring systems of PN stage oocytes might help to offer patients in Germany the transfer of two selected PN oocytes, which would reduce the multiple pregnancy rate.     

Observational clinical follow-up of oocyte cryopreservation using a slow-freezing method with 1,2-propanediol plus sucrose followed by ICSI

BACKGROUND: The value of oocyte cryopreservation remains controversial. Two major problems exist: poor survival and injury to the oocyte meiotic spindle after freezing and thawing. METHODS: For slow oocyte cryopreservation, we used 1.5 mol/l 1,2-propanediol and 0.3 mol/l sucrose. We waited 3 h after thawing for possible recovery of the meiotic spindles before performing ICSI. RESULTS: Forty-three women undergoing IVF or ICSI cycles cryopreserved some or all of their harvested oocytes; of these, 20 thawed their cryopreserved oocytes for personal use and one for donation. The survival rate of oocytes after thawing was 75%, with 67% of oocytes fertilizing normally after ICSI. All 21 cycles (100%) resulted in fertilization and embryo transfers. Seven pregnancies (33%) resulted. Four women delivered five babies with normal karyotypes. Three conceptions are ongoing. Compared to 38 cycles of frozen-thawed embryos at the pronuclear stage in the same period, the percentages of survival, pregnancy and implantation were similar. Additionally, four unmarried women with white blood cell diseases underwent oocyte freezing before preconditioning treatment for haematopoietic stem cell transplantation. CONCLUSIONS: This protocol achieved reproducible success of survival, fertilization and pregnancy for freezing and thawing of human oocytes. The 3 h post-thaw incubation could permit restoration of the meiotic spindles, thus facilitating normal fertilization.     

Retrospective multicentre study on mechanical and enzymatic preparation of fresh and cryopreserved testicular biopsies

BACKGROUND: Isolation of sperm suitable for ICSI from fresh or frozen-thawed testicular sperm extraction (TESE) can be facilitated by mechanical or enzymatic processing of the samples. METHODS: A retrospective multicentre study was initiated to compare these two approaches. Eleven German centres provided data on their TESE cycles performed during the period 1996/1997. Quality of retrieved sperm, fertilization rates of injected oocytes, embryo quality, resulting pregnancy rates and evolution of pregnancies were evaluated. RESULTS: The percentage of cycles with at least some motile sperm available for injection was higher after mechanical preparation. Independent of the preparation method, fertilization rates were higher for motile compared with immotile sperm or elongated spermatids in all groups and in general higher for cryopreserved versus fresh samples. Embryo quality was significantly better after injection of motile sperm for all treatments and in particular after enzymatic versus mechanical processing of biopsies. Pregnancy rates were identical for embryos derived from sperm prepared mechanically or enzymatically from fresh or cryopreserved testicular samples. The abortion rate (32/172, 18.6%) and the rate of multiple implantations (32/140, 22.9%) were not different from results reported in the literature for ICSI using ejaculated sperm. CONCLUSION: In this retrospective multicentre study, no unequivocal advantage of one over the other preparation method could be identified in 839 ICSI cycles using testicular sperm from 549 patients.     

Outcome of testicular sperm retrieval procedures in non-obstructive azoospermia: percutaneous aspiration versus open biopsy

The aim of this study was to evaluate whether the extraction of testicular spermatozoa with percutaneous versus open biopsy has an effect on the treatment outcome with intracytoplasmic sperm injection (ICSI) in men with non-obstructive azoospermia. Regardless of testicular size, follicle stimulating hormone concentration, and previous biopsy result, percutaneous testicular sperm aspiration (PTSA) using a 21-gauge butterfly needle was attempted first and if this failed testicular sperm extraction (TESE) was performed. In 63 men spermatozoa were found with PTSA whereas in 228 men TESE had to be undertaken. More men in the PTSA group had previously been diagnosed with hypospermatogenesis (82 versus 50%). Compared with the PTSA group, more men in the TESE group had germ cell aplasia (27 versus 10%) or maturation arrest (22 versus 8%). There was no difference between the groups regarding mean age of men and their partners, duration of stimulation, oestradiol concentration on the day of human chorionic gonadotrophin, number of oocytes retrieved, fertilization rate, and embryo quality between the two groups. The number of embryos transferred (4.38 versus 3.90) was significantly higher in the PTSA group (P < 0.05), reflecting the increased number of embryos available for transfer. Implantation rate per embryo was 20.7% in the PTSA and 13.3% in the TESE group (P < 0.05). Clinical pregnancy rates were 46 and 29% in the PTSA and TESE groups respectively (P < 0.05). Clinical abortion rates were similar (21.2 versus 24%). It is concluded that in men with non-obstructive azoospermia, easier sperm retrieval, which is most likely indicative of a more favourable histopathology, is associated with higher implantation rates per embryo.     

Human preimplantation embryo cryopreservation: selected aspects

This report describes the results of cryopreserving human preimplantation zygotes and cleaved embryos (2-4 cells) in our in-vitro fertilization programme. Cryopreserved zygotes and cleaved embryos resulted in similar post-thaw survival rates (74.8 versus 70.9%). Pregnancy rates per retrieval cycle (RC) and embryos transferred per pregnancy for frozen-thawed zygotes versus frozen-thawed cleaved embryos were 21.8 versus 11.5% (P less than 0.2) and 12.6 versus 17.5 (P less than 0.2), respectively. Pregnancy rates increased significantly for both fresh (P less than 0.0005) and frozen-thawed (P less than 0.05) embryos as the number of embryos replaced per transfer increased from one to three or more. Frozen-thawed embryos resulted in multiple implantation rates per transfer of 25 compared to 6.4% (P less than 0.1) for fresh embryos when two embryos were replaced. Pregnancy rates were reduced for fresh (P less than 0.05) and frozen-thawed (P less than 0.1) embryos obtained from patient retrieval cycle numbers greater than 3. The method of follicular stimulation during the retrieval cycle did not affect frozen-thawed embryo survival rates. There was no difference in pregnancy rates from frozen-thawed embryos replaced during natural or clomiphene citrate transfer cycles. Patients with cryopreserved embryos had cumulative pregnancy rates of 37.1% (66/178) compared to 23.5% (110/468) (P less than 0.01) for patients with no embryos cryopreserved; cryopreservation of preimplantation embryos is a reliable therapeutic procedure that enhances achievement of pregnancy through in-vitro fertilization.     

常规IVF受精失败补救ICSI后行冻融胚胎移植的临床价值

目的探讨冻融胚胎移植在常规体外受精(IVF)失败后补救卵胞浆内单精子注射(L-ICSI)中的应用价值。方法在12个常规体外受精失败周期中应用ICSI对未受精的MⅡ期卵子进行显微授精,将获得的优质胚胎进行冷冻,再择期行冻融胚胎移植。结果对93个未受精的MⅡ卵子接受L-ICSI,受精63枚,受精率为67.7%(63/93),异常受精3枚(2枚1PN,1枚3PN),57个正常受精卵发生卵裂,卵裂率为95.0%(57/60),优质胚胎率为43.9%(25/57),10例患者冷冻胚胎25枚,其中4例采用程序化冷冻,6例采用玻璃化冷冻。9个患者行冻融胚胎移植,共移植胚胎18枚(其中解冻后胚胎碎裂死亡5枚),其中1个周期因冻融后2个胚胎碎裂放弃移植,2例获得临床妊娠,1例分娩出正常婴儿,1例正在妊娠中,临床妊娠率为22.2%。结论 ICSI可使常规体外受精失败的卵子再受精,冻融胚胎移植可以解决胚胎与子宫内膜不同步的问题,获得相对满意的临床结局,具有一定的应用价值。