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Eight infertile men with various degrees of oligoasthenoteratozoospermia and repeated implantation failure were selected for this study due to exceptionally high rates of sperm aneupoidy in their ejaculates. All subjects had normal physical examination, karyotype and serum FSH concentration. Prior to IVF treatment, spermatozoa was collected, processed, micromanipulated and tested for chromosomes X, Y and 18 using fluorescence in-situ hybridization. Aneupoidy rates for chromosomes X, Y and 18 were determined among sperm population selected for normal morphology using high-order magnification light microscopy. A second group of fast motile spermatozoa were collected using an intracytoplasmic sperm injection pipette from the medium-oil interface from microdroplets. The average aneuploidy rates for the three chromosomes were 7.6% (395/5182) in the sperm specimen before selection, 8.7% (116/1326) in the normal morphology selected group and 4.3% (59/1388; P<0.001) in the fast motile selected group. In conclusion, high-magnification light microscopy aimed at selection of spermatozoa with normal morphology did not affect the aneuploidy rate. On the other hand, fast motile spermatozoa harboured significantly less chromosomal abnormalities (P<0.001). Preselection of the most rapid sperm subpopulation for intracytoplasmic sperm injection may improve the qualities of the fertilizing spermatozoon., (Copyright © 2013 Reproductive Healthcare Ltd. Published by Elsevier Ltd. All rights reserved.)

The introduction of intracytoplasmic sperm injection and the use of spermatozoa extracted from the testicles have changed the option for conception for azoospermic patients. The purpose of the present study was to evaluate the IVF outcome after using cryopreserved testicular sperm samples in comparison with fresh ones. A total of 667 in vitro fertilisation cycles with fresh or cryopreserved testicular sperm obtained by an open biopsy and testicular needle aspiration were evaluated. Sperm motility was present in 70.9% of the cycles in Group-I, 77.8% cycles in Group-II and in 83.3% In Group-III (NS). The fertilisation rates were similar in the three study groups (50%, 48.6% and 54.8% respectively). The pregnancy rates were 26.7%, 22.2% and 16.3% respectively (NS). The delivery rate, however, was significantly lower in Group-III (4.1%) than in Group-I and -II (18.4% and 15.9%, respectively, P < 0.05). The IVF results after use of cryopreserved testicular sperm are comparable with those obtained with the fresh specimens. Lack of sperm motility before cryopreservation does not exclude favourable outcome and therefore testicular sperm freezing is feasible whenever there are enough sperm cells in the extracted testicular tissue., (© 2011 Blackwell Verlag GmbH.)

Objective: To evaluate ultrasonically the incidence and duration of tissue damage after testicular sperm aspiration (TESA) procedures., Design: Prospective, nonrandomized study., Setting: Assisted reproductive technology program., Patient(s): Thirty-two men with obstructive azoospermia., Intervention(s): Physical and serial testicular ultrasound examinations 1.5, 3, and 6 months after the surgical procedure., Main Outcome Measure(s): Systematic evaluation of the testicular parenchyma and blood flow., Result(s): In 93.7% of the patients (30 of 32), no evidence of parenchymal or vascular injuries was found 6 weeks after the procedure. In the remaining 2 patients, transient evidence of tissue damage disappeared after 3 months., Conclusion(s): Testicular sperm aspiration is a safe surgical method for sperm retrieval for IVF. Repeated surgical attempts might be considered within 2 months, provided there is no evidence for tissue damage on sonography.

The aim of the study was to determine the rate of chromosome abnormalities in testicular sperm after intracytoplasmic sperm injection due to severe male factor infertility. The study groups included patient with non-obstructive azoospermia (n=9), obstructive azoospermia (n=10), Klinefelter's syndrome (n=5) and normal controls (n=6, groups I-VI, respectively). The mean serum levels of FSH 17.5+/-8.2 (P<0.05), 3.5+/-2.6, 29.8+/-13.0 (P<0.05) and 3.1+/-0.4 mIU/ml, respectively. The rates of chromosome abnormalities were 19.6% (P<0.001), 8.2% (P<0.001), 6.3 and 1.6%, respectively. Chromosomes X and Y were significantly more involved in the aneuploidy than chromosome 18 in groups I and II. The present findings demonstrate a linkage between gonadal failure (high serum FSH levels) and sperm chromosome abnormalities. Our findings may explain the increased incidence of perinatal sex chromosome abnormalities found in severe male factor patients. Patients with non-mosaic Klinefelter's syndrome have comparable risk for sex chromosomes aneuploidy as the rest of the patients with azoospermia. Therefore, genetic screening during pregnancy or before embryo replacement should be carefully considered in severe male factor patient following in vitro fertilization (IVF).

Objective: To investigate the potential paternal contribution to the risk of fetal chromosomal anomalies after intracytoplasmic sperm injection (ICSI)., Design: Spermatozoa isolated from testicular tissue and ejaculated specimens of consenting patients undergoing testicular biopsy and ICSI were analyzed for chromosomes X, Y, and 18 by FISH., Setting: Assisted reproductive technology program., Patient(s): Consenting patients undergoing testicular biopsy and ICSI, severe oligozoospermic patients, and normal fertile donors., Intervention(s): None., Main Outcome Measure(s): The rate of chromosome abnormalities in testicular sperm with regard to the type of azoospermia and ejaculated sperm compared to healthy men., Result(s): The mean serum levels of FSH in the groups with nonobstructive azoospermia (n = 9), obstructive azoospermia (n = 10), severe oligozoospermia (n = 9), and the normal donors (n = 6) were 17.5 +/- 8.2 (P<.05), 3.5 +/- 2.6, 14.6 +/- 3.5 (P<.05), and 3.1 +/- 0.4 IU/mL, respectively. The corresponding rates of sperm chromosome abnormalities among these groups were 19.6% (P<.001), 8.2% (P<.001), 13.0% (P<.001), and 1.6%, respectively. The corresponding rates of disomy among these groups were 7.8% (12 of 153 spermatozoa), 4.9% (18 of 367), 6.2% (109 of 1,751), and 1% (5 of 500 spermatozoa), respectively. Errors in chromosomes X and Y were significantly more common than in chromosome 18., Conclusion(s): The present findings demonstrate a linkage between gonadal failure (high serum FSH levels) and the occurrence of sperm chromosome aneuploidies. Our findings may explain the increased incidence of sex chromosome abnormalities found after IVF in the severe male factor patient population. Genetic screening during pregnancy or before embryo replacement should be considered carefully.

Objective: The aim of the study was to determine the potential risk for fetal chromosomal anomalies in non-mosaic Klinefelter's syndrome patients undergoing IVF and intracytoplasmic sperm injection., Design: Individually collected spermatozoa were isolated from wet testicular tissue preparations and fixed on glass slides using micromanipulation. Their nuclei were analyzed for chromosomes X, Y, and 18 by fluorescent in situ hybridization., Setting: Assisted reproductive technology program., Patient(s): Consenting patients with non-mosaic Klinefelter's syndrome undergoing testicular biopsy and IVF (fresh specimens) or following such treatment (cryopreserved specimens)., Intervention(s): None., Main Outcome Measure(s): The rates of numerical chromosome abnormalities for chromosomes X, Y, and 18 among spare testicular sperm and the pregnancy outcome following treatment., Result(s): Testicular sperm were found in 8 of 20 patients. Four couples became pregnant following embryo replacement. Sperm chromosomes were analyzed in five patients. One hundred and five sperm of 112 analyzed (93.7%) were normal with X to Y ratio of 50:55 (NS) respectively. Among the 112 sperm tested, seven (6.3%) demonstrated chromosomal abnormalities, of which five were related to the sex chromosomes and two to chromosome 18. One set of triplets, one set of twins, and two singletons (four males and three females) with normal karyotypes were born., Conclusion(s): Most of the testicular sperm retrieved from Klinefelter's syndrome patients demonstrates a normal pattern of sex chromosome segregation. Therefore, the risk of transmitting numerical sex chromosome abnormalities is relatively low and probably comparable with the rates found in other severe male factor infertility patient groups.

Follicular fluid (FF) induces sperm chemotaxis in human spermatozoa. Progesterone also causes sperm accumulation. However, sperm accumulation can be caused by chemotaxis, chemokinesis, and trapping of various kinds. It has been suggested that progesterone also induces chemotaxis in human spermatozoa. In view of the physiological significance of sperm chemotaxis in human fertilization and its potential clinical implications, it is important to determine unequivocally whether chemotaxis is induced by progesterone and, if so, whether progesterone in FF is the chemoattractant. To resolve these questions we looked for characteristic changes in the direction of sperm swimming toward pure progesterone as well as toward FF before and after progesterone removal. Progesterone caused sperm accumulation and hyperactivation-like motility, but it caused very few changes in the direction of sperm swimming that are characteristic of chemotaxis. Removal of progesterone (and other steroids) from FF by charcoal treatment abolished the sperm hyperactivation-like motility but not sperm chemotaxis. These results suggest that while progesterone might be a weak chemoattractant, it is not the major chemoattractant in FF. Progesterone probably causes human sperm accumulation mainly by inducing hyperactivation-like motility and, as a consequence, sperm trapping.

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.

Objective: To report the successful use of testicular sperm aspiration and intracytoplasmic sperm injection in the presence of an Escherichia coli-infected ejaculate that previously caused repeated embryo degeneration., Design: Case report., Setting: University medical center., Patient(s): A 38-year-old woman who did not conceive for 6 years with repeated IVF attempts. Escherichia coli was isolated from both the oocyte culture dish and her male partner's ejaculate., Intervention(s): Testicular sperm aspiration and intracytoplasmic sperm injection followed by ET., Main Outcome Measure(s): Clinical outcome., Result(s): Establishment of a pregnancy delivered at term., Conclusion(s): Patients undergoing IVF treatment who have repeated embryo degeneration caused by bacterial infection originating in the ejaculate may be treated successfully with testicular sperm aspiration and intracytoplasmic sperm injection.

Due to a paucity of donated eggs, we have excluded, until recently, couples with severe male factor infertility from our egg donation programme, except for those who accepted insemination with donor spermatozoa. The purpose of this study was to assess the feasibility of a shared in-vitro fertilization (IVF)-embryo transfer treatment whenever the recipients have severe oligoasthenoteratozoospermia (OTA) and need intracytoplasmic sperm injection (ICSI) for egg fertilization. The results from 163 consecutive couples with ovarian failure who underwent 273 cycles of IVF with donated eggs and augmented with ICSI were analysed. The rate of diploid fertilization was 54.7%; in 92.3% of the cycles, at least one embryo was available for transfer. Forty-seven clinical pregnancies were achieved, representing 18.6% conceptions per transfer. The highest pregnancy rate was achieved in menopausal patients aged 40-45 years (26.2% per cycle) and the lowest in patients >45 years old (10.8% per cycle, P = 0.03). Overall, 28.8% of the couples achieved a clinical pregnancy. A total of 196 treatment cycles resulted in 46 clinical pregnancies (23.5%) among the donors. No statistical differences were found in pregnancy rate achieved by the donors when compared with the recipients. We conclude that ICSI with egg donation is a reliable treatment in patients with ovarian failure and severe OTA.

Purpose: Our purpose was to evaluate whether the source of spermatozoa influences the results of intracytoplasmic sperm injection (ICSI) treatment in couples with severe male-factor infertility., Methods: A retrospective analysis of 40 cases of ICSI with testicular-retrieved spermatozoa, matched with 40 cases of ICSI with ejaculated spermatozoa, was performed. We included only couples with normoovulatory females younger than 37 years who were matched according to the day of ovum pickup with the patients in the study group., Results: Eighty cycles were analyzed: 40 cycles using testicular spermatozoa and 40 cycles using ejaculated spermatozoa. In 32 (80%) of the 40 ICSI transcutaneous needle aspiration cycles, we obtained enough spermatozoa to inject all the mature oocytes retrieved. In eight (20%) cases there were not enough spermatozoa to inject all the oocytes. Only 76 (54%) of 141 available oocytes were injected in these eight patients. The oocyte fertilization rates were 42% for the study group and 55.5% for the controls (P < 0.005). Thirty-six (90%) patients in the group with nonobstructive a zoospermia (NOA) and 37 (92.5%) patients in the oligoteratoasthenospermia (OTA) group had embryos for replacement. The mean cleavage rates per cycle (96% with testicular and 93% with ejaculated spermatozoa), the mean number of embryos per transfer (3.72 +/- 1.6 in the NOA group and 4.24 +/- 1.5 in the OTA group), the embryo quality (cumulative embryo scoring = 34.03 +/- 22.62 in the testicular sperm group and 36.08 +/- 19.28 in the ejaculated sperm group), and the clinical pregnancy rates (22.5% in the NOA patients and 20% in the ejaculate group) were not significantly different between groups., Conclusions: High fertilization, cleavage, and pregnancy rates can be achieved with intracytoplasmic testicular sperm injection from patients with NOA, reaching levels comparable with those of ICSI using ejaculated spermatozoa.

Routine semen analysis in an infertile patient revealed severe teratospermia associated with malformation of head and tail in 100% of the sperm cells. Flow cytometry and fluorescence in-situ hybridization (FISH) were shown to supplement routine semen analysis by providing information on the sperm chromatin. Using flow cytometry, propidium iodide-stained spermatozoa from the same sperm sample were compared with a normal reference pool, and with human lymphocytes. The results point to a population of diploid sperm cells rather than to mature haploid spermatozoa. Numerical chromosomal abnormalities of the spermatozoa were subsequently evaluated using FISH. A total of 1000 sperm cells were scored for X and Y chromosomes, and an additional 1128 sperm cells for chromosome 18. Aneuploidy of chromosomes X and Y was revealed in 96.9% of the cells and of chromosome 18 in 90.3% of the cells. Non-disjunction of chromosome X and Y in meiosis I and II occurred in 54.8 and 2.7% of the sperm cells respectively. Non-disjunction in both meiosis I and II occurred in 39.4% of the sperm cells. A normal haploid pattern for chromosomes X and Y was observed in only 3.1%, and for chromosome 18 in 9.7%, of the cells. Using three colour FISH for the sex chromosomes and for chromosome 18, diploidy was demonstrated in 19.4% of 500 sperm cells and aneuploidy in virtually all sperm cells (99.2%). The use of flow cytometry and FISH in cases where genetic and developmental chromatin abnormalities are suspected is a valuable adjunct to other available techniques, and can guide the clinicians to decide which samples are unsuitable for intracytoplasmic injection.

In all, 58 couples suffering from infertility because of congenital bilateral absence of the vas deferens underwent a total of 67 combined microsurgical epididymal aspiration or testicular sperm extraction (TESE) and in-vitro fertilization (IVF) treatments. The oocytes recovered were inseminated by either the microdroplet IVF technique (N = 20), subzonal insemination (SUZI; n = 10) or intracytoplasmic sperm injection (ICSI; n = 37). Of the ICSI cycles, 12 were performed using spermatozoa obtained by TESE. Fertilization rates for epididymal spermatozoa were significantly higher for SUZI (17.9%, 17/95) and ICSI (34.4%), 137/398) than for microdroplet IVF (5.2%, 18/343) cycles. The proportion of cycles in which fertilization was achieved was higher in the SUZI (80%) and ICSI (95%) cycles than in the IVF cycles (45%). Delivery or an ongoing pregnancy was achieved in one (5%) IVF cycle, two (20%) SUZI cycles and seven (18.95) ICSI cycles. SUZI or ICSI using epididymal or testicular spermatozoa significantly improved the oocyte fertility rate. The ICSI procedure was especially advantageous in patients for whom spermatozoa were obtained from a testicular biopsy.

In humans, only a small fraction (2-12%) of a sperm population can respond by chemoattraction to follicular factors. This recent finding led to the hypothesis that chemotaxis provides a mechanism for selective recruitment of functionally mature spermatozoa (i.e., of capacitated spermatozoa, which possess the potential to undergo the acrosome reaction and fertilize the egg). This study aimed to examine this possibility. Capacitated spermatozoa were identified by their ability to undergo the acrosome reaction upon stimulation with phorbol 12-myristate 13-acetate. Under capacitating conditions, only a small portion (2-14%) of the spermatozoa were found to be capacitated. The spermatozoa were then separated according to their chemotactic activity, which resulted in a subpopulation enriched with chemotactically responsive spermatozoa and a subpopulation depleted of such spermatozoa. The level of capacitated spermatozoa in the former was approximately 13-fold higher than that in the latter. The capacitated state was temporary (50 min < life span < 240 min), and it was synchronous with the chemotactic activity. A continuous process of replacement of capacitated/chemotactic spermatozoa within a sperm population was observed. Spermatozoa that had stopped being capacitated did not become capacitated again, which indicates that the capacitated state is acquired only once in a sperm's lifetime. A total sperm population depleted of capacitated spermatozoa stopped being chemotactic. When capacitated spermatozoa reappeared, chemotactic activity was restored. These observations suggest that spermatozoa acquire their chemotactic responsiveness as part of the capacitation process and lose this responsiveness when the capacitated state is terminated. We suggest that the role of sperm chemotaxis in sperm-egg interaction in vivo may indeed be selective recruitment of capacitated spermatozoa for fertilizing the egg.

Human spermatozoa accumulate in vitro in diluted follicular fluids obtained from follicles from which the eggs have been fertilized. Using capillary assays under a variety of experimental conditions (ascending or descending gradients of follicular fluid, or no gradient at all) and microscopic assays in which individual spermatozoa could be followed, we found that the sperm accumulation in follicular fluid was the result of both sperm chemotaxis and chemokinesis and eventually hyperactivation-like motility. We determined the optimal conditions for sperm accumulation, which involved sperm preincubation (possibly to induce sperm capacitation) and proper dilution of follicular fluid. In all the assays, the net accumulation was low, probably reflecting the chemotactic responsiveness of only a small fraction of the sperm population at any given time. We partially fractionated follicular fluid in a Centricon microconcentrator (Amicon, Danvers, MA) and by acetone precipitation, and found that at least one of the chemotactic factors is a small (< 10-kDa) molecule that is probably nonhydrophobic. This is the first time that sperm chemotaxis and chemokinesis in response to a follicular factor(s) in mammals has been established and has been distinguished from other processes that might cause sperm accumulation. The physiological significance of these findings is discussed.

Recent studies have indicated that human spermatozoa respond to follicular fluid by attraction to chemotactic factor(s) in the fluid, accompanied by enhancement of motility and ultimately hyperactivation. In this study, we quantified the sperm response. We exposed spermatozoa to a gradient of a chemotactically active fraction of follicular fluid (denoted as "the attractant") and separated the spermatozoa that accumulated in the attractant and those that did not. We thus obtained two subpopulations: one enriched with chemotactically responsive spermatozoa, and one deficient in such spermatozoa. The fraction of the responsive spermatozoa out of the total sperm population was 2-12% at any measured time point. With time, the responsive spermatozoa lost their ability to be attracted, while such activity was gradually acquired by the subpopulation originally deficient in responsive spermatozoa. These results indicate that the identity of responsive spermatozoa is continuously changing. If the in vitro results are representative of the physiological conditions in vivo, they imply that the role of sperm chemotaxis combined with enhanced motility may be to select capacitated spermatozoa and bring them to the egg. Such a mechanism may, over an extended period of time, increase the prospect that an egg will meet capacitated spermatozoa as soon as it ovulates.

An in vitro nuclear chromatin decondensation test, and quantitative nuclear ultramorphology analysis, were performed on 18 males judged to be infertile, by two failures in in vitro fertilization, and 16 fertile males. These two clinical groups only differed significantly in (1) the direction of their chromatin stability change, which took place 30-120 min post-ejaculation while stored in the seminal plasma, and (2) in the incidence of the hypoelongated sperm-head. Generally, the fertile male group exhibited positive chromatin stability change after prolonged storage, and low incidence of hypoelongated sperm heads, and vice versa in the unexplained infertile group. When the nuclear chromatin decondensation test and quantitative ultramorphology analysis were performed in step-wise fashion, it was possible to correctly classify 94% of the fertile cases with 6% of false-negative, and 89% of the unexplained infertile cases with 11% of false-positive. Therefore, it appears that these tests might be of benefit clinically for identifying functional properties of sperm-cells in unexplained infertile males, which cannot be detected by routine semen analysis.

Spermatozoa normally encounter the egg at the fertilization site (in the Fallopian tube) within 24 hr after ovulation. A considerable fraction of the spermatozoa ejaculated into the female reproductive tract of mammals remains motionless in storage sites until ovulation, when the spermatozoa resume maximal motility and reach the fertilization site within minutes. The nature of the signal for sperm movement is not known, but one possible mechanism is attraction of spermatozoa to a factor(s) released from the egg. We have obtained evidence in favor of such a possibility by showing that human spermatozoa accumulate in follicular fluid in vitro. This accumulation into follicular fluid was higher by 30-260% than that observed with buffer alone and was highly significant (P less than 10(-8)). Not all of the follicular fluids caused sperm accumulation; however, there was a remarkably strong correlation (P less than 0.0001) between the ability of follicular fluid from a particular follicle to cause sperm accumulation and the ability of the egg, obtained from the same follicle, to be fertilized. These findings suggest that attraction may be a key event in the fertilization process and may give an insight into the mechanism underlying early egg-sperm communication.

Anti-zona antibodies are effective inhibitors of fertilization in vitro and, regardless of whether passive or active immunization techniques are used, in vivo. Antibodies raised against unfractionated zona pellucida antigens are chiefly directed against a group of carbohydrate-rich components localized on the outer surface of the zona. The interaction of anti-zona antibodies with these sites induces the formation of a surface precipitate which occludes the sperm binding sites by a process of steric hindrance, and stabilizes the zona structure against digestion by the proteolytic enzymes of the sperm head. Active immunization studies indicate that the long-term induction of infertility without adverse side effects is feasible in both laboratory rodents and primates when the zona pellucida is used as a target. Anti-sperm antibodies also exhibit a capacity for inhibiting fertilization in vivo and in vitro. To determine the most appropriate detection method to screen patients for anti-sperm antibodies several homologous and heterologous antisera were analysed by 5 different agglutination and immobilization techniques and then compared for their ability to inhibit the fertilizing capacity of human spermatozoa using the zona-free hamster egg penetration test. The results obtained with the Franklin--Dukes tube--slide test exhibited the closest correlation with the anti-fertility activity of a given antiserum; this activity could be amplified by the addition of complement to the medium. It is concluded that antibodies directed against the sperm head are responsible for limiting the fertilizing capacity of human spermatozoa in vitro and that it is these antibodies of which attention should be focused to unravel the role that immunological factors play in the aetiology of infertility in vivo.

The influence of antisperm antibodies on the fertilizing capacity of human sperm was investigated in a zone-free hamster egg system using heterologous and homologous antisera. The ability of these antisera to interfere with the fertilizing capacity of human spermatozoa correlated well with the antibody titers obtained using the Franklin-Dukes tube slide test. However, there was little correlation between the antifertility effects of these antisera and their activities in the gelatin and tray agglutination tests. The addition of complement to the incubation medium amplified the inhibitory activity exhibited by these antisera, although the extent of this inhibitory influence bore no relationship to the antibody titers obtained using the complement-dependent sperm-immobilization technique. The study demonstrates the importance of the hamster egg penetration test in evaluating the antifertility effect of antisperm antibodies.

The ability of sperm samples from male partners of infertile couples, with isolated teratospermia (ITS), to penetrate zona-free hamster eggs was examined. The ITS patients had a significantly lower proportion of normal spermatozoa than did a control group of men of proven fertility (23.6% and 47.8%, respectively; P less than 0.001), while the mean total sperm count and the % motility did not differ between the two groups. The mean hamster egg penetration rate of sperm from ITS patients was 2.64% compared to 31.1% in the control group. A significant negative correlation was found in the ITS group between the proportion of a) abnormal forms and the ability to penetrate zona-free hamster eggs, and b) pyriform-shaped sperm and the penetration rate. Of the sperm parameters which were examined, only the morphology could be correlated with the rate of penetration.

The possibility of the immunological factor as an etiological cause of infertility was investigated in 50 infertile couples. Of these, 31 couples were considered as an "unexplained sterility" group, while in the other 19 couples a variety of disorders were diagnosed. In vitro, leucocyte migration inhibition test (LMIT) was used for the detection of female cell-mediated immunity against sperm antigens. Sperm immobilization test (SIT) and sperm toxicity tests (STT) were used for the detection of antisperm antibodies in the cervical mucus. Out of the 31 "unexplained sterility" cases, six revealed a positive LMIT (5.3%). In 26 couples with an abnormal postcoital test (PCT), 10 cases had a positive SIT and STT (38.5%). However, out of the group of 16 couples with a normal PCT only in one case was a positive SIT and STT found (6.2%). The potential role of immunological reactions in infertility will be discussed.