Influence of motility and vitality in intracytoplasmic sperm injection with ejaculated and testicular sperm

The vitality of spermatozoa used for intracytoplasmic sperm injection (ICSI) is a crucial factor for fertilization, establishment and outcome of a pregnancy in assisted reproductive technique cycles. The sperm origin may also be a limiting factor, although little is known about this issue. It is known that the motility of injected spermatozoa and their origin from ejaculate or testicular biopsies are important predictors in terms of fertilization, pregnancy and birth rates. Oocytes of patients in 2593 cycles were retrieved in our in vitro fertilization programme and inseminated via ICSI. We used motile (group 1, n = 2317) or immotile ejaculated spermatozoa (group 2, n = 79), motile sperm retrieved from testicular biopsies (group 3, n = 62) and immotile spermatozoa from testicular biopsies (group 4, n = 135). Female age and number of oocytes retrieved did not differ significantly among the groups. The fertilization rates were as follows: 67.1% in group 1, 49.8% in group 2, 68.3% in group 3 and 47.8% in group 4. The pregnancy rates in cases where three embryos had been transferred amounted to 35.7% in group 1, 17.3% in group 2, 38.3% in group 3 and 20.5% in group 4. The embryo quality showed no differences between groups 1 and 3 (14.5), and between groups 2 (11.8) and 4 (10.8). The abortion rate was similar in groups 1-3, but increased in group 4 (26.6%, 27.3%, 31.6% and 55.5%). Irrespective of their origin, the fertilization potential of injected spermatozoa was found to be influenced by motility. The resulting pregnancy and birth rates, i.e. the potential of the resulting embryos to implant and to achieve viable pregnancies, seem to be additionally dependent on the sperm origin. This was well shown by declining rates when spermatozoa in a relatively early stage of maturity had been used. We see increasing evidence that the degree of sperm maturity has an important impact on the outcome of ICSI. In obstructive azoospermia, spermatozoa retrieved from the epididymis should be used rather than testicular biopsy spermatozoa, or testicular sperm should be preincubated in culture medium before ICSI.     

睾丸精子获取和单精子卵胞浆内注射术治疗非梗阻性无精子症不育

目的　探讨非梗阻性无精子症患者外科获取睾丸精子的方法和意义。　方法　 4 9例非梗阻性无精子症患者行开放睾丸活检和诊断性睾丸精子获取术 (TESE) ,诊断性TESE有精子者至少 3个月后行单精子卵胞浆内注射 (ICSI)治疗。　结果　 12例 (2 4 .9% )诊断性TESE中发现精子 ,其中 3例为生精减少 ,2例为生精阻滞 ,7例为Sertoli细胞综合征。睾丸体积、血FSH水平和睾丸病理类型不能准确预测是否有精子。 8例行ICSI治疗 ,7例 (87.5 % )再次TESE获得睾丸精子行显微注射 ,3例获得临床妊娠。　结论　非梗阻性无精子症患者有必要行诊断性TESE确定睾丸内是否存在精子 ,获取睾丸精子结合ICSI可以有效治疗非梗阻性无精子症不育。     

Intracytoplasmic sperm injection outcomes with cryopreserved testicular sperm aspiration samples

Intracytoplasmic sperm injection (ICSI) may be performed with testicular frozen–thawed spermatozoa in patients with nonobstructive azoospermia (NOA). Sperm retrieval can be performed in advance of oocyte aspiration, as it may avoid the possibility of no recovery of spermatozoa on the day of oocyte pickup. There are few studies available in the literature concerning the use of frozen–thawed spermatozoa obtained from testicular sperm aspiration (TESA). To evaluate the effects and the outcomes of ICSI with frozen–thawed spermatozoa obtained by TESA, we performed a retrospective analysis of 43 ICSI cycles using frozen–thawed TESA. We obtained acceptable results with a fertilisation rate of 67.9%, an implantation rate (IR) of 17.1%, and clinical and ongoing pregnancy rates of 41.9% and 37.2% respectively. The results of this study suggest that performing ICSI using cryopreserved frozen–thawed testicular spermatozoa with TESA as a first option is a viable, safe, economic and effective method for patients with NOA.     

Sperm retrieval from a male with the rare 47, XXYqs variant of Klinefelter syndrome for intracytoplasmic sperm injection: A case report

A 27-year-old man with nonobstructive azoospermia was diagnosed with Klinefelter syndrome (KS) with a satellite Y chromosome (47, XXYqs) by karyotyping. Genetic analysis revealed azoospermia factor c (AZFc) microdeletion of gr/gr deletion in the Y chromosome. Microdissection testicular sperm extraction (micro-TESE) was performed in bilateral testes. Very few seminiferous tubules were bilaterally observed, and a minute number of spermatozoa obtained from the left testis were cryopreserved. Histologic examination of the left testicular tissue revealed severe tubular atrophy with only Sertoli cells accompanied by Leydig cell hyperplasia. Oocyte harvest was conducted in his wife in two different cycles after ovarian stimulation, and intracytoplasmic sperm injection was performed for 24 oocytes (8 and 16 oocytes respectively) using thawed spermatozoa. Fertilisation was confirmed in total of 19 oocytes (79.2%), with 15 cleaved embryos (62.5%). Two cleavage-stage embryos were cryopreserved at day 2, but no blastocysts developed. Frozen–thawed embryo transfer was performed using two cleavage-stage (day 2) embryos; however, the wife did not conceive. In conclusion, spermatozoa were successfully obtained by micro-TESE from a patient with 47, XXYqs. Despite failure of conception, the fertilisation and cleavage rates were comparable or better than those reported in patients with “typical” KS.     

Pregnancy following intracytoplasmic sperm injection of immotile spermatozoa selected by the hypo-osmotic swelling-test: a case report

Summary.  The success of intracytoplasmic sperm injection (ICSI) is poor when only immotile spermatozoa can be retrieved. In a couple with complete male asthenozoospermia the possible use of the hypo-osmotic swelling test to select spermatozoa for microinjection was examined. Following incubation in hypo-osmotic medium (Hypo 10, IVF Science, Göteborg, Sweden), 26% of immotile spermatozoa showed signs of sperm swelling (HOS-positive). After injection of HOS-positive spermatozoa, 5 out of 12 oocytes fertilized (41%) and after transfer of three embryos a healthy singleton pregnancy was achieved. In a previous ICSI cycle of this couple without preselection of spermatozoa by the HOS test, only 1 out of 10 oocytes fertilized. It is concluded that selection of spermatozoa by hypo-osmotic swelling-test prior to sperm microinjection seems to be a valuable tool to increase the fertilization rate in cases with complete asthenozoospermia.     

非嵌合型克氏综合征显微睾丸取精术后临床妊娠1例报告及文献复习

目的 探讨非嵌合型克氏综合征患者生育遗传学意义后代的可行性.方法 1例就诊于华中科技大学同济医学院附属同济医院的男性患者,年龄29岁,多次精液分析提示无精子,查体双侧睾丸体积小,质硬,约2 ml.性激素水平:卵泡刺激素37.34 IU/L,黄体生成素15.69 IU/L,明显升高;睾酮2.13 ng/ml,稍微偏低.查染色体核型为47,XXY,Y染色体微缺失正常,确诊为非嵌合型克氏综合征.行显微睾丸取精术,同时配合女方取卵后行卵细胞胞质内单精子注射(intracytoplasmic sperm injection, ICSI),随访1个月,观察患者术后并发症及其配偶妊娠情况.结果 显微睾丸取精术中找到少量活动精子,次日女方取卵后行ICSI,3 d后移植2枚新鲜胚胎.术后患者未出现阴囊血肿、感染等并发症,术后随访1个月患者睾酮水平较术前偏低,但性功能未受到影响.女方移植后2周查血HCG,为801 mIU/ml;移植后4周超声提示宫内早孕,单胎,胚胎存活.结论 非嵌合型克氏综合征患者可通过显微睾丸取精术获取精子,同时配合ICSI技术,生育自己遗传学意义的后代.     

Individual assessment of sperm morphology of single spermatozoa used for intracytoplasmic sperm injection

Intracytoplasmic sperm injection (ICSI) is an integral part of assisted reproduction. Although many papers have shown that global sperm count, sperm motility and sperm morphology of the ejaculate play no role in the fertilization rate after ICSI, embryologists who carry out ICSI, try to use the 'best looking' spermatozoa. The aim of the study was to investigate whether those spermatozoa with the best morphology really achieve the highest fertilization rate. In the present study, a total of 798 spermatozoa used for ICSI were documented by high-resolution photo. After ICSI the oocytes were cultured in single droplets and the formation of pronuclei was assessed 16 h later. The spermatozoa (all normal according to WHO criteria) were classified into four groups of different morphology. Group 1: normal head shape (approximately 5 microm diameter), group 2: like group 1, but with 15-20% smaller diameter, group 3: like group 1, but with 15-20% larger diameter, and group 4: like group 1, but with slight mid-piece cytoplasmic irregularities. Using the Pearson chi-square test, no significant difference in terms of fertilization was found among the different groups, showing that marginal sperm differences do not alter the fertilization process in ICSI.     

Male factors determining the outcome of intracytoplasmic sperm injection with epididymal and testicular spermatozoa

During a period of 8 years, 1,079 intracytoplasmic sperm injection (ICSI) procedures with aspirated epididymal or testicular spermatozoa were performed. Epididymal spermatozoa were used in 172 cycles and testicular spermatozoa or spermatids in 907 cycles. Multiple biopsies were obtained from at least two different locations in the testes. Retrieved spermatozoa were used after cryopreservation (frozen) or immediately after aspiration (fresh). Three hundred patients had obstructive azoospermia (OA) or ejaculation failure. In 414 cases, azoospermia was caused by impaired spermatogenesis resulting from maldescended testes, chemotherapy/radiotherapy, or by Sertoli-cell-only syndrome, genetic disorders or unknown aetiology. Transfer rates, pregnancy rates and birth rates per ICSI cycle showed no statistically significant differences between testicular and epididymal spermatozoa in men with OA (28% average birth rates in both cases). However, birth rates differed significantly with regard to the status of spermatogenesis. Treatment of men with nonobstructive azoospermia (NOA) resulted in a birth rate of 19% per cycle. In all patient groups, there was no difference in the birth rates achieved with fresh and cryopreserved spermatozoa. While testicular volume, follicle-stimulating hormone level and age of the male patient are no statistically significant prognostic factors, the underlying cause of azoospermia is the most important factor determining the outcome of ICSI with epididymal and testicular spermatozoa. The pregnancy rate is lower in NOA patients than in those with OA.     

Birth after intracytoplasmic sperm injection of ejaculated spermatozoa from a man with mosaic Klinefelter＇s syndrome

Aim: To report a birth after intracytoplasmic sperm injection (ICSI) of ejaculated spermatozoa from a man with mosaic Klinefelter‘s syndrome detected by fluorescence in situ hybridization (FISH) analysis. Methods: A 35-year-old man with a normal appearance consulted our hospital because of sterility over a 5-year period. Chromosome analysis showed low-incidence mosaic Klinefelter‘s syndrome. Using FISH, 96% hyperploidy of the lymphocytes was found. We examined the sex chromosome of the ejaculated spermatozoa. Using FISH, we examined 200 ejaculated spermatozoa and no hyperploidy was found. Results: The 33-year-old female partner of the male patient underwent an uncomplicated controlled ovarian hyperstimulation sequence using a combined recombinant-follicle stimulating hormone (rec-FSH) human menopausal gonadotrophin (hMG) protocol, following late luteal phase pituitary down regulation. This culminated in the retrieval of seven oocytes, six of which were fertilized with ICSI.One ICSI attempt led to clinical pregnancy with a healthy baby girl. Conclusion: We report a male patient with lowincidence mosaic Klinefelter‘s syndrome whose ejaculated spermatozoa were identified as being haploid by FISH before ICSI, leading to the successful pregnancy of his wife and the birth of a healthy baby girl.     

Intracytoplasmic sperm injection by testicular sperm in patients with aspermia or azoospermia after cancer treatment

The aim of this retrospective study was to evaluate the efficiency of testicular biopsy and intracytoplasmic sperm injection (ICSI) in patients with aspermia or non-obstructive azoospermia (NOA) after cancer treatment. From 1996 to 2003, 30 men with a history of cancer, affected by aspermia or NOA and without sperm cryopreserved before cytotoxic treatment underwent testicular sperm extraction (TESE). In these men, clinical, hormonal and histological characteristics were compared; 13 underwent 39 TESE-ICSI cycles using frozen-thawed testicular spermatozoa (TESE-ICSI group). In the same period, 31 ICSI cycles were performed in 20 men with aspermia or NOA using ejaculated sperm frozen before cancer treatment (ejaculated sperm-ICSI group). Fertilization, blastocyst development, pregnancy and miscarriage rates were compared between the groups. Testicular volume, serum follicle-stimulating hormone level and Johnsen score indicated complete although reduced spermatogenesis in men with aspermia and abnormal spermatogenesis in men with NOA. After TESE, sperm retrieval was positive in 92% of men with aspermia and 58% of men with NOA. In TESE-ICSI patients with NOA a significantly lower proportion of embryos developed to the blastocyst stage than in patients with aspermia and in those after ICSI with frozen-thawed ejaculated sperm (23% vs. 43% and 47%, p = 0.03 and p < 0.01 respectively). In all groups the miscarriage rates were high; in patients with aspermia and NOA, characterized by increased age, the miscarriage rate tended to be higher in spite of similar female age and female indications of infertility. In patients affected by aspermia or NOA after cancer treatment and without sperm cryopreserved before treatment, TESE-ICSI using testicular sperm provide a chance to father a child.     

Ongoing pregnancies resulting from intracytoplasmic sperm injection (ICSI) of spermatozoa from frozen-thawed testicular biopsy specimens

Two clinical pregnancies following intracytoplasmic sperm injection of spermatozoa from frozen-thawed testicular biopsies in two azoospermic men are reported. The use of spermatozoa from cryopreserved testicular tissue is therefore a viable option for azoospermic men, as our results indicate that pregnancies is achievable in these cases.     

Birth of healthy twins after intracytoplasmic sperm injection using ejaculated immotile spermatozoa from a patient with Kartagener's syndrome

This case report demonstrates a successful pregnancy after ICSI combined with hypo-osmotic swelling test in a couple with Kartagener's syndrome with complete immotile ejaculated spermatozoa. Our result suggests that even for complete immotile spermatozoa, the use of hypo-osmotic swelling test is a good alternative to identify viable spermatozoa. When associated with ICSI, it can be a valuable tool to get fertilisation and pregnancy.     

比较金黄地鼠和人卵浆内单精子注射技术受精率

卵浆内单精子注射技术（ｉｎｔｒａｃｙｔｏｐｌａｓｍｉｃｓｐｅｒｍｉｎｊｅｃｔｉｏｎ，ＩＣＳＩ）１９９２年后已广泛应用于治疗严重的男性不孕患者，平均受精率可达６５％～７０％。但仍有大约１／３的卵在ＩＣＳＩ后未能受精。金黄地鼠ＩＣＳＩ试验（ｈａｍｓｔｅｒ ＩＣＳＩａｓａｙ）可能有助于在临床ＩＣＳＩ治疗前了解精子受精的潜力。为了证明金黄地鼠ＩＣＳＩ和人类ＩＣＳＩ受精率之间的相关性，探索金黄地鼠ＩＣＳＩ能否用为临床ＩＣＳＩ的预试验，本研究采用同一男性不孕患者的精子经显微注射技术在同一天分别注入人和金黄地鼠卵。１６～１８小时后在光镜下观察有无双原核形成（２ ｐｒｏｎｕｃｌｅｕｓ，２ＰＮ）。人卵１１０个其受精率为５８２％（６４／１１０）。金黄地鼠卵１１４个其受精率为１６５％（１４／８０）。经统计学处理，二者无相关性。金黄地鼠ＩＣＳＩ分为两组，Ａ组：无选择地注射了已激活与未激活的卵６３个；Ｂ组：注意选择未激活的卵共５１个。虽经统计学处理无明显差异，但仍可看出Ｂ组的损伤率（１９７±１６６％）低于Ａ组（３５９±５．７％）（Ｐ＝００８）；而Ｂ组的受精率（１８３±１０．９％）略高于Ａ组（１４２±８．７％）（Ｐ＝０?     

不同生精功能障碍无精子症患者行ICSI后胚胎发育潜能的研究

目的:分析不同生精功能障碍的无精子症患者行ICSI后其胚胎发育潜能。方法:149例患者分为生精功能正常组,轻度、中度和重度生精功能障碍组,采用经皮附睾精子抽吸术(PESA)或经皮睾丸精子抽吸术(TESA)抽取不同生精功能障碍患者的精子行ICSI,记录和分析胚胎的正常受精率、卵裂率、优良胚胎形成率以及妊娠率。结果:PESA与TESA组比较,正常受精率(%)为74.9±19.6 vs 66.3±22.7(P>0.05),卵裂率(%)为96.7±8.6 vs 92.8±19.8(P>0.05),优良胚胎率(%)为43.5±26.2 vs 35.0±29.4(P>0.05)以及妊娠率(%)为44.0 vs 52.0(P>0.05),均无统计学差异。生精功能障碍从正常组到重度组的正常受精率(%)变化依次为77.8±18.4、68.4±18.5、73.5±19.8、51.4±27.9,其中轻度生精功能障碍与正常生精组有差异(P<0.05),重度生精功能障碍组与其他各组有统计学差异(P<0.05);胚胎卵裂率(%)变化依次为96.7±9.2、96.5±15.0、93.9±12.1、93.7±11.1,各组无统计学差异;优良胚胎率(%)变化依次为47.1±25.8、40.3±27.6、36.2±23.1、15.0±24.6,重度生精障碍组与其他各组有统计学差异(P<0.05);妊娠率(%)依次为54.8%、50.0%、13.6%、10.0%,有统计学差异(P<0.05)。结论:采用PESA或TESA行ICSI在正常受精率,卵裂率,优良胚胎率以及妊娠率上较均无明显差异。随着患者生精障碍程度的加重,受精率、优良胚胎率以及妊娠率均显著下降,而卵裂率却无明显区别。     

Fertilization of in vitro matured human oocytes by intracytoplasmic sperm injection （ICSI） using ejaculated and testicular spermatozoa

AIM: To evaluate the fertilization competence of spermatozoa from ejaculates and testicle when the oocytes were matured in vitro following intracytoplasmic sperm injection (ICSI). METHODS: Fifty-six completed cycles in 46 women with polycystic ovarian syndrome were grouped according to the semen parameters of their male partners. Group 1 was 47 cycles that presented motile and normal morphology spermatozoa in ejaculates and Group 2 was the other nine cycles where male partners were diagnosed as obstructive azoospermia and spermatozoa could only be found in testicular tissue fragment. All female patients received minimal stimulation with gonadotropin. Immature oocytes were matured in vitro and inseminated by ICSI. The spermatozoa from testes were retrieved by testicular fine needle aspiration. RESULTS: A total of 449 and 78 immature oocytes were collected and cultured for 48 hours, 75.5 % (339/449) and 84.6 % (66/78) oocytes were matured in Groups 1 and 2, respectively. The percentage of oocytes achieving normal fertilization was significantly higher in Group 1 than that in Group 2 (72.9 % vs. 54.5 %, P 0.05). There were no significant differences in the rates of oocytes cleavage and clinical pregnancies in these two groups [87.4 % (216/247) vs. 88.9 % (32/36); 21.3 % (10/47) vs. 44.4 % (4/9)]. A total of 15 babies in the two groups were healthy delivered at term. CONCLUSION: It appears that IVM combined with ICSI using testicular spermatozoa can produce healthy infants, while the normal fertilization rate of in vitro matured oocytes after ICSI using testicular spermatozoa was significantly lower than using the ejaculated spermatozoa.     

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.     

The effects of female age on the outcome of testicular sperm extraction and intracytoplasmic sperm injection in infertile patient 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.     

Testicular spermatozoon is superior to ejaculated spermatozoon for intracytoplasmic sperm injection to achieve pregnancy in infertile males with high sperm DNA damage

The purpose of this study was to compare the clinical outcome of testicular spermatozoon versus ejaculated spermatozoon in the treatment of infertile males with high sperm DNA damage, referred as sperm DNA fragmentation index (DFI), that attending intracytoplasmic sperm injection (ICSI) programme in terms of clinical pregnancy, births delivered as the primary and pregnancy loss and embryo fertilisation as the secondary outcome. A total of 102 males fulfilling the inclusion criteria were enrolled in the present study. Of the 102 males, 61 infertile males underwent testicular spermatozoon combined with ICSI while the remaining 41 males applied ejaculated spermatozoa in their first ICSI cycles, and the data of them were collected and analysed. In a 18‐month follow‐up, testicular spermatozoon achieved higher pregnancy rate and deliver rate than those in ejaculated sperm group (pregnancy rate, 36% vs. 14.6%, p = 0.017; deliver rate, 38.5% vs. 9.8%, p = 0.001). Nevertheless, there were no significant differences in the number of oocytes aspirated and number of embryos transferred between the two groups. Additionally, the fertilisation rate in the testicular sperm study cohort (70.4%) was also similar to that in the ejaculated sperm group (75.0%). Based on the current data, we conclude that testicular spermatozoon is the prior option in the treatment of infertile males with high sperm DFI in ICSI programme. More high‐quality studies with larger samples size are needed in the future due to the relative small size and the nonrandomized design of the present study.     

Comparison of the outcome of intracytoplasmic sperm injection in obstructive and non-obstructive azoospermia in the first cycle: a report of case series and meta-analysis

To investigate the outcome of intracytoplasmic sperm injection with fresh and cryopreserved-thawed testicular spermatozoa in the first cycle in patients with obstructive azoospermia (OA) and non-obstructive azoospermia (NOA), a total of 90 cases, 48 OA and 42 NOA were studied. All patients underwent sperm retrieval by testicular sperm extraction (TESE) while their wives received conventional ovarian hyperstimulation. The hormone levels, testicular histology, the rates of sperm retrieval, fertilization, implantation and pregnancy were analysed and evaluated. This study and other four similar studies were subjected to meta-analysis. Sperm retrieval was successful in 100% OA and 61% NOA. Fresh spermatozoa were used in 87.5% and 92.4% of OA and NOA cases respectively; while cryopreserved-thawed spermatozoa were used in 12.5% and 7.6% of OA and NOA, respectively. The fertilization, implantation and clinical pregnancy rates were 65.5%, 15% and 25% respectively in OA group, and 54.2%, 5% and 23.1% respectively in NOA group. Sperm status (fresh or thawed), male partner's age, female age and male serum follicle-stimulating hormone had no significant effect upon fertilization rate, implantation rate, or pregnancy rate per embryo transfer. The results of meta-analysis indicate that there is no statistically significant difference in clinical pregnancy rates between the two groups. There was a significantly higher fertilization rate among OA patients in all analysed studies (95% CI = 14.29-15.71, d.f. 832, T = 1.96). In conclusion, although the fertilization rate was significantly higher in the OA group in our study and from the given meta-analysis, there were some differences as regards pregnancy rates. Although the overall effect was more or less similar pregnancy rates in both subtypes of azoospermia, this may not be true if non-male infertility variables were controlled for in all studies.