Microsurgical Epididymal Sperm Aspiration Research Articles

Efficacy of microsurgical epididymal sperm aspiration (MESA) and intracytoplasmic sperm injection (ICSI) in obstructive azoospermia.

Our purpose was to test whether micromanipulation using subzonal insemination and intracytoplasmic sperm injection could improve the poor fertilization and pregnancy rates obtained when attempting in vitro fertilization in patients with congenital absence of the vas deferens and unreconstructable obstructive azoospermia with microsurgically retrieved epididymal spermatozoa. Conventional in vitro fertilization (group A; 14 cycles), subzonal insemination (group B; 13 cycles), and intracytoplasmic sperm injection (group C; 28 cycles) were carried out in 55 treatment cycles. Fertilization rates for groups A, B, and C were 16.1, 31.4, and 48.6%, respectively (P < 0.05). Clinical pregnancy rates for groups A, B, and C were 7.1, 7.7, and 32.1% (P < 0.05), respectively. In five cycles, intracytoplasmic sperm injection using epididymal sperm from alloplastic spermatoceles was performed and two clinical pregnancies (40%) were obtained. The combined microsurgical epididymal sperm aspiration and intracytoplasmic sperm injection procedure is highly effective in improving the fertilization and pregnancy rate in congenital absence of the vas deferens and unreconstructable obstructive azoospermia. Furthermore, alloplastic spermatoceles may be useful for repeat sperm aspirations.

Efficacy of intracytoplasmic sperm injection using intentionally cryopreserved epididymal spermatozoa.

Microsurgical epididymal sperm aspiration was a great advance in the therapy of patients with non-reconstructable, obstructive azoospermia, most notably congenital bilateral absence of the vas deferens. Using conventional in-vitro fertilization, pregnancies were rarely achieved because the rate of oocyte fertilization was extremely poor. However, the use of retrieved spermatozoa in conjunction with intracytoplasmic sperm injection (ICSI) has dramatically increased the likelihood of embryo formation. Typically, sperm and oocyte harvesting are performed simultaneously. We have investigated whether frozen-thawed spermatozoa work as well as fresh spermatozoa. When we had concluded from our own population of patients (groups I and II) that they did, we adopted a policy of aspirating spermatozoa, primarily cryopreserving them and using them for ICSI at a later date. We found the fertilization rates of this latter cohort of patients (group III) to be excellent (37% per oocyte), and the ongoing pregnancy rate is quite satisfactory (40% per couple, 29% per cycle). We offer this approach as an alternative to the traditional scheme because it markedly eases the burden of partner scheduling on both the couple and the clinicians involved. In addition, assurance of the availability of male partner spermatozoa can be attained prior to beginning ovulation induction.

Testicular needle biopsy, open biopsy, epididymal aspiration and intracytoplasmic sperm injection in obstructive azoospermia

Testicular or epididymal spermatozoa were obtained for in-vitro fertilization and intracytoplasmic sperm injection (ICSI) in 27 cycles out of 33 (in six men the azoospermia proved to have testicular causes). Testicular needle biopsy carried out in addition to surgical open biopsy proved to be an effective method to obtain spermatozoa for ICSI from patients with obstructive azoospermia. Thus it might be possible to replace scrotal operations by simple needle biopsies. Embryos resulting from ICSI with testicular spermatozoa were used in 19 transfers that resulted in six pregnancies. One pregnancy resulted from six embryo transfers from ICSI after microsurgical-epididymal sperm aspiration (MESA). The normal fertilization rates with testicular (37.3%) and MESA spermatozoa (53.7%) did not differ significantly from each other, but with testicular spermatozoa the rate was significantly lower than that obtained with ejaculated spermatozoa and ICSI (59.7%) in the matched couples. The abnormal fertilization of oocytes with one pronucleus was significantly higher with testicular spermatozoa than with ejaculated spermatozoa in the control couples.

Successful fertilization, pregnancy, and birth using epididymal sperm frozen 24 hours after conventional oocyte insemination

To assess if epididymal sperm cryopreserved 24 hours after exposure to oocytes in conventional IVF can be successfully used for intracytoplasmic sperm injection (ICSI) in a subsequent cycle. Case report. University of California, Irvine, Center for Reproductive Health. Two men with obstructive azoospermia requiring microsurgical epididymal sperm aspiration, IVF, and ICSI. Freezing of epididymal sperm 24 hours after egg exposure in conventional IVF and subsequent use for assisted fertilization in a new cycle. Frozen-thawed epididymal sperm survivability and maintenance of fertilization and pregnancy capacity. At the time of sperm aspiration procedure (cycle I) a total of 30 oocytes were available for insemination. Of these, 15 were used for conventional IVF resulting in 2 embryos (13%) and 15 were used for ICSI, resulting in 3 embryos (20%). Sperm was cryopreserved 24 hours after conventional IVF and thawed 6 months later in a new cycle. Upon thawing, sperm were still found to be motile and at this time (cycle II) only assisted fertilization was used. Of 27 oocytes injected, 12 (44%) produced normal, cleaving embryos. One singleton pregnancy with the birth of a healthy infant girl was achieved after the tubal transfer of 5 embryos. The birth of a normal, healthy infant girl with epididymal sperm frozen 24 hours after exposure to oocytes in conventional IVF emphasizes the value of freezing any aliquot of epididymal sperm, even if the motility is very low, to avoid additional surgery in the male. From a basic science standpoint, this observation may renew interest in the study of sperm cryopreservation after occurrence of acrosome reaction and hyperactivation.

Fertilization and pregnancy achieved by intracytoplasmic injection of sperm retrieved from testicular biopsies

To determine if intracytoplasmic sperm injection using testicular sperm is effective in the treatment of infertile couples with obstructive azoospermia. Case report. Tertiary care teaching medical center. Intracytoplasmic sperm injection was performed in two patients using testicular sperm after microsurgical epididymal sperm aspiration failed. In both cases fertilization and embryos resulted. One patient conceived and delivered triplets. There was no evidence of chromosomal abnormality or congenital malformation. Intracytoplasmic sperm injection using sperm extracted from testicular biopsy appears to be effective in the treatment of infertile couples with obstructive azoospermia when microsurgical sperm aspiration fails.

Genetics: The use of epididymal and testicular spermatozoa for intracytoplasmic sperm injection: the genetic implications for male infertility

The results and rationale of using testicular and epididymal spermatozoa with intracytoplasmic sperm injection (ICSI) for severe cases of male infertility are reviewed. A total of 72 consecutive microsurgical epididymal sperm aspiration (MESA) cases were performed for congenital absence of the vas (CAV) and for irreparable obstructive azoospermia. ICSI was used to obtain normal embryos for transfer and fertilization in 90% of the cases. The overall fertilization rate was 46% with a normal cleavage rate of 68%. The pregnancy and delivery rates per transfer were 58 and 37% respectively. The delivery rate per cycle was 33%. In many cases, no epididymal spermatozoa were available and so testicular sperm extraction (TESE) was used for sperm retrieval. The transfer rate was lower with TESE (84 versus 96%) and the spermatozoa could not be frozen and saved for use in future cycles. However, there was little difference in pregnancy rates using epidiymal or testicular spermatozoa. The results were not affected by whether the obstruction was caused by CAV or failed vasoepididymostomy. Both fresh and frozen spermatozoa gave similar results; the only significant factor appeared to be the age of the female. Because of the consistently good results obtained using epididymal sperm with ICSI when compared with conventional IVF, and the similarly good results with testicular tissue spermatozoa, ICSI is mandatory for all future MESA patients. All CAV patients and their partners should be offered genetic screening for cystic fibrosis; hence pre-implantation embryo diagnosis should be available in any full service MESA programme. It is now clear that even with non-obstructive azoospermia, e.g. Sertoli-cell only, or maturation arrest, there are usually some small foci of spermatogenesis which allow TESE with ICSI to be carried out. This means that even in men with azoospermia due to absence of spermatogenesis or to a block in meiosis, there are usually a few spermatozoa available in the testes that are adequate for successful ICSI. Finally, it is likely that some forms of severe male factor infertility are genetically transmitted and although ICSI offspring have been shown to be completely normal, it is possible that the sons of these infertile couples will also require ICSI when they grow up and wish to have a family.

Fertilization and early embryology: Ongoing pregnancies and birth after intracytoplasmic sperm injection with frozen—thawed epididymal spermatozoa

In seven patients who did not become pregnant following microsurgical epididymal sperm aspiration (MESA) and intracytoplasmic sperm injection (ICSI), a subsequent ICSI was performed using previously cryopreserved super-numerary epididymal spermatozoa without re-operating on the husband. During the original MESA procedure a mean sperm concentration of 12.3 x 10(6)/ml was achieved. The supernumerary spermatozoa were cryopreserved for later use. After thawing frozen epididymal spermatozoa a mean concentration of 1.9 x 10(6) spermatozoa/ml was obtained in straws containing a total volume of sperm suspension of 250 microliters. From 68 intact oocytes injected with frozen-thawed epididymal spermatozoa, a two pronuclear fertilization rate of 45% and a cleavage rate of 82% were obtained. A total of 17 embryos were replaced in the seven patients, resulting in two ongoing singleton pregnancies and one twin delivery. Six embryos were cryopreserved. In conclusion, it would appear mandatory to cryopreserve supernumerary spermatozoa during a MESA in order to avoid subsequent further scrotal surgery.

Microsurgical epididymal sperm aspiration and intracytoplasmic sperm injection: A new effective approach to infertility as a result of congenital bilateral absence of the vas deferens: Tournaye H.; Devroey P.; Liu J.; Nagy Z.; Lissens W.; Van Steirteghem A. BEL Fertil Steril 1994 61/6 (1045–1051)

Microsurgical epididymal sperm aspiration and intracytoplasmic sperm injection: A new effective approach to infertility as a result of congenital bilateral absence of the vas deferens: Tournaye H.; Devroey P.; Liu J.; Nagy Z.; Lissens W.; Van Steirteghem A. BEL Fertil Steril 1994 61/6 (1045–1051)

Use of epididymal sperm for assisted reproduction in men with acquired, irreparable obstructive azoospermia

Microsurgical epididymal sperm aspiration (MESA) and in vitro fertilization (IVF) is primarily offered to men with congenital absence of the vas deferens (CAVD). However, the IVF capacity of these epididymal sperm is low ( < 15%) and unpredictable. In this study, IVF and intracytoplasmic sperm injection (ICSI) results in patients with non-congenital, irreparable obstructive azoospermia were analysed. Thirty-three patients were evaluated for a total of 37 cycles of MESA and IVF. Most had obstruction secondary to failed vasectomy reversal and to epididymal blockage. The overall fertilization rate was 30% with regular IVF and 26% with ICSI, and six clinical pregnancies were obtained. Both rates are significantly higher than the IVF rate previously reported with sperm from men with CAVD (13%, P < 0.00001). In men with non-congenital obstructive azoospermia, a significant difference was found in the average sperm count (56.9 x 10(6) v. 12.3 x 10(6), P < 0.04) and total motile count (16.6 x 10(6) v. 1.6 x 10(6), P < 0.01) respectively for patients who achieved IVF and those who did not. It is concluded that (a) the real IVF capacity of human epididymal sperm is 30%, or 42%, if calculated only for patients who achieved fertilization, (b) this higher rate is an indirect support of the hypothesis that sperm from men with CAVD have intrinsic biochemical defects, related to cystic fibrosis mutations, responsible for their low and unpredictable IVF rate, and (c) MESA and IVF can be offered at the same time or as an alternative to patients requesting vasectomy reversal.

High fertilization and pregnancy rate after intracytoplasmic sperm injection with spermatozoa obtained from testicle biopsy

In cases requiring microsurgical epididymal sperm aspiration (MESA) for congenital absence of the vas deferens (CAVD) or irreparable obstructive azoospermia, often no spermatozoa can be retrieved from the epididymis, or there may even be no epididymis present. We wished to see whether testicular biopsy with testicular sperm extraction (TESE) in such cases could yield spermatozoa that would result in successful fertilization and pregnancy (despite the absence of epididymal spermatozoa) using intracytoplasmic sperm injection (ICSI). In the same setting during the same 2-week period, 28 patients with CAVD or irreparable obstruction were treated; 16 consecutive fresh MESA-ICSI cycles and 12 cycles which required testicular biopsy with testicular sperm extraction (TESE-ICSI) were performed. Normal two-pronuclear fertilization rates were similar in both groups: 45% for epididymal spermatozoa and 46% for testicular biopsy-extracted spermatozoa. Cleavage rates were also similar (68% for epididymal and 65% for testicular spermatozoa). The ongoing pregnancy rates in this series were 50 and 43% respectively. We conclude that epididymal spermatozoa and testicular spermatozoa yield similar fertilization, cleavage and ongoing pregnancy rates using ICSI. When epididymal spermatozoa cannot be retrieved, a testicular biopsy can be performed and the few barely motile spermatozoa thus obtained can be used for ICSI. It appears that all cases of obstructive azoospermia can now be successfully treated.

Intracytoplasmic sperm injection (ICSI): the Brussels experience

The present report covers the results of a 26-month period in which 1275 consecutive treatment cycles by intracytoplasmic sperm injection (ICSI) were performed in 919 couples. These couples were afflicted with male factor infertility and had had at least one previous failed conventional in vitro fertilization (IVF) treatment cycle. In other couples, the husband had semen parameters incompatible with conventional IVF or suffered from excretory azoospermia which required microsurgical epididymal sperm aspiration or testicular sperm retrieval. Overall, the 2 pronuclear (PN) fertilization rate was 47.7% per retrieved oocyte-cumulus complex and 66.4% per successfully injected metaphase II oocyte. Embryo transfer was performed in 90.8% of started cycles and 362 clinical pregnancies were recorded, giving a clinical pregnancy rate of 28.4% per started cycle or 31.3% per transfer. In addition, updated results on the outcome of pregnancies after microassisted fertilization are presented. As of 30 August 1994, 416 children have been born. Although 16 major congenital malformations have been observed (3.9%), there appears to be no reason for serious concern as regards the occurrence of major congenital anomalies after ICSI.

Birth After Preimplantation Diagnosis of the Cystic Fibrosis △F508 Mutation by Polymerase Chain Reaction in Human Embryos Resulting From Intracytoplasmic Sperm Injection With Epididymal Sperm

Men with congenital bilateral absence of the vas deferens (CBAVD) have been regarded as presenting a mild form of cystic fibrosis (CF). In this article, we report a case of male-factor infertility, in which both partners are carriers of the delta F508 mutation and the male partner has CBAVD. Microsurgical epididymal sperm aspiration (MESA) was performed to obtain spermatozoa; intracytoplasmic sperm injection (ICSI) was carried out on the oocytes since the motility of the spermatozoa was severely impaired; and embryo biopsy and a polymerase chain reaction (PCR) were carried out for preimplantation diagnosis of the CF delta F508 mutation. Single-blastomere analysis was performed and indicated that two embryos were affected (homozygous delta F508) and three embryos were carriers. After transfer of the latter three embryos, a singleton pregnancy was established. At amniocentesis, the delta F508 carrier status of the fetus with a 46, XY karyotype was confirmed. A healthy boy was born and the presence of vasa deferentia, bilaterally, was confirmed. The CF sweat test was also normal. Successful fertilization can be obtained by combination of MESA and ICSI in patients with CBAVD. Preimplantation diagnosis of CF is indicated. Pregnancy and birth of normal children can ensue in such patients.

Microsurgical epididymal sperm aspiration and intracytoplasmic sperm injection: a new effective approach to infertility as a result of congenital bilateral absence of the vas deferens

To present and assess the efficacy of a new approach for the treatment of infertility due to congenital bilateral absence of the vas deferens. A retrospective study of consecutive trials. Centre for Reproductive Medicine, which is a tertiary referral institution. Twelve couples suffering from infertility because of congenital bilateral absence of the vas deferens. A microsurgical epididymal sperm aspiration procedure was performed in the husbands, followed by intracytoplasmic sperm injection of oocytes recovered from the wives. Cleaving embryos were transferred to the uterine cavity 48 hours after the intracytoplasmic sperm injection procedure. Sperm parameters after microsurgical epididymal sperm aspiration, fertilization, cleavage, and pregnancy rates. In all 14 microsurgical epididymal sperm aspiration procedures, sperm was retrieved. Notwithstanding the poor quality of this epididymal sperm, a fertilization rate of 58% was achieved after intracytoplasmic sperm injection. On 10 occasions, embryos were transferred and five patients became pregnant, i.e., an overall pregnancy rate of 35.7% per started trial and 50.0% per transfer. Another two patients became pregnant after replacement of frozen-thawed embryos, which increases the pregnancy rate to 50.0% per microsurgical epididymal sperm aspiration procedure. Early pregnancy wastage was 57%, limiting the ongoing pregnancy rate to 21.4% per microsurgical epididymal sperm aspiration procedure. This study shows the combined microsurgical epididymal sperm aspiration-intracytoplasmic sperm injection procedure to be highly efficient in achieving fertilization in vitro, even after recovery of grossly impaired epididymal sperm.

Correlation between epididymal length and fertilization rate in men with congenital absence of the vas deferens

To investigate whether the variable length of the epididymides in men with congenital absence of the vas deferens might have a correlation with IVF and pregnancy rate results. Microsurgical retrieval of epididymal sperm from men with congenital absence of the vas deferens and their use for IVF. Center for Reproductive Health, University of California, Irvine, California. One hundred eight men with confirmed diagnosis of congenital absence of the vas deferens enrolled in the microsurgical epididymal sperm aspiration and IVF program. Measurement in centimeters of the epididymal length at the time of the sperm aspiration procedure. Rates of fertilization and pregnancy according to the epididymal length. Three groups were identified: group I (n = 29), epididymal length between 0.5 and 1.9 cm; group II (n = 66), length between 2.0 and 4.0 cm; and group III (n = 13), length in excess of 4.0 cm. Although the aspiration site was the proximal caput for each case, patients of group III had the highest fertilization and pregnancy rate (24% and 43%, respectively). Patients with the shortest epididymis (group I) had the worst IVF outcome (fertilization rate 7% and pregnancy rate 7%) whereas in group II the fertilization rate was 13% and the pregnancy rate was 18%. This study demonstrates that epididymal sperm from men with congenital absence of the vas deferens having a longer epididymis have a better IVF rate. A long epididymis can allow [1] the arrival of more frequent waves of fresh sperm whereas in a short epididymis the system is completely congested and occupied by old and senescent sperm, [2] less obstructive damages, and [3] a back flow of biochemical factors produced in the more distal segments that could ultimately enhance the fertilization capacity of proximal epididymal sperm.

Azoospermia Ostruttiva: Incidenza, Tecnica e Risultati

From 1991 to February 1994 we observed 40 patients affected by azoospermia. The reasons for azoospermia were various: contraceptive vasectomy 2 patients, deferential agenesia 2 patients, bilateral testicular hypotrophy 12 patients, specific and aspecific infections 8 patients, hypogonadotropic hypogonadism 1 patient, Klinefelter syndrome 1 patient, 5 patients had severe oligoastenospermia (&lt; 5 mil/ml) with mono and bilateral epididymal cysts connected with left varicocele in one patient. 9 patients with azoospermia had II and III degree varicocele. In 5 patients recanalization was carried out: epididymovasostomy in 2 cases (1 laterolateral and 1 terminoterminal) and vasovasostomy (3 cases). In the 2 patients who underwent microsurgical epididymal sperm aspiration (MESA) we took from 12 to 38 millions of spermatozoa. 40 days after the recanalization, spermatozoa appeared in the semen of all the patients. In the azoospermic patients affected by varicocele who underwent venous reflux correction, no spermatozoa were found after 18 months. Only a few azoospermic patients (12.5%) could undergo the recanalization treatment.

Andrology: Cystic fibrosis mutations impair the fertilization rate of epididymal sperm from men with congenital absence of the vas deferens

One of the limiting factors for the successful treatment of male sterility due to congenital absence of the vas deferens (CAVD) is the low (< 20%) and extremely unpredictable rate of in-vitro fertilization of their epididymal spermatozoa. The recent demonstration that CAVD is a mild form of cystic fibrosis (CF) disease, almost exclusively involving the genital tract, has prompted us to investigate the hypothesis of whether there could be an association between particular CF genotype mutations and the in-vitro performance of epididymal sperm. In this study 63 patients with surgically confirmed diagnosis of CAVD undergoing microsurgical epididymal sperm aspiration (MESA) and in-vitro fertilization (IVF) were evaluated. The genetic screening was carried out on DNA extracted from peripheral lymphocytes and amplified by the polymerase chain reaction. A total of 12 mutations in the cystic fibrosis transmembrane regulator gene (CFTR), representing approximately 90% of the total known CF mutations, were tested. The presence or absence of mutations, as well as the type of mutation found, was correlated with the IVF and pregnancy rates. Of the 63 patients examined, 40 (64%) were positive to the CF screening and 23 were negative. In three cases no spermatozoa were found because of rete testis blockage. The difference in fertilization rates between patients testing positive and negative was highly significant (P = 0.000003), 13 versus 23%, respectively. In order to pinpoint which mutation could account for the most deleterious effect on the IVF results, we analysed these by keeping the patients separated by CF mutations.(ABSTRACT TRUNCATED AT 250 WORDS)

Relationship of epididymal sperm antibodies to their in vitro fertilization capacity in men with congenital absence of the vas deferens

To test, using the immunobead binding technique, for the presence of antisperm antibodies on epididymal sperm, in epididymal fluid, and in serum of men with congenital absence of the vas deferens. To evaluate the in vitro fertilization (IVF) capacity of human epididymal sperm in the presence of antisperm antibodies.Prospective. At the time of oocyte insemination, sperm from the proximal caput epididymis or vasa efferentia were tested by direct immunobinding technique. The epididymal fluid and serum were tested by indirect immunobinding technique.Center for Reproductive Health, University of California-Irvine.Forty-five patients with congenital absence of the vas deferens participating in the microsurgical epididymal sperm aspiration and IVF program.Incidence of antisperm antibodies to epididymal sperm and their relationship with IVF results.Sixteen men (35%) tested positively to the direct immunobead test on epididymal sperm; 7 (16%) were positive in epididymal fluid and 13 (29%) were positive in serum. Five pregnancies (31%) occurred in the positive group of which two were from patients who had sperm binding of 100% for immunoglobulin (Ig)G (all over sperm surface) and 90% (midpiece, tail) and 50% (tail, tiptail), respectively, for IgA. Five pregnancies (18%) were obtained in the negative group. No statistical difference was observed in the overall fertilization rate between the two groups.Human epididymal sperm and epididymal fluid retrieved from men with congenital absence of the vas deferens can react positively to immunobead test. However, the presence of antisperm antibodies do not seem to impair the IVF capacity of epididymal sperm.

Aetiology of congenital absence of vas deferens: genetic study of three generations.

Bilateral congenital absence of the vas deferens (CAVD) is a form of male sterility (found in otherwise normal men) of unknown aetiology. Because males with cystic fibrosis (CF) almost invariably have CAVD as well, we investigated the hypothesis that men with isolated CAVD might share a common genetic background with males with CF. Genetic testing for CF was carried out in three generations of subjects: 44 patients with CAVD and their wives, 24 of their parents, and 13 of their offspring generated by microsurgical epididymal sperm aspiration (MESA) and in-vitro fertilization (IVF). DNA extracted from peripheral lymphocytes was amplified by the polymerase chain reaction (PCR) and then analysed for 12 mutations in the cystic fibrosis transmembrane conductance regulatory (CFTR) gene. Among 44 patients tested with CAVD, 26 (59%) were positive for at least one CF mutation, while the carrier frequency for CF mutations in the general population is only 4%. Four patients were found to be compound heterozygotes, three with genotypes Delta F-508/R117H, one with R553X/R117H. Among 24 parents tested, 15 (seven fathers, eight mothers) had sons with CAVD who were positive for CF mutations. Of these, nine (four fathers and five mothers) were found to be carriers for CF mutations. These four fathers, although carriers of CF mutations, were obviously fertile. Of the 13 offspring tested, six (three boys and three girls) had CF positive fathers. Of these, three (two girls and one boy) were found to be carriers for CF mutations. These MESA/IVF children are the first offspring to whom men with CAVD have been able to transmit CF mutations.(ABSTRACT TRUNCATED AT 250 WORDS)

A simplified method for processing sperm obtained during microsurgical epididymal sperm aspiration (MESA) for use in in vitro fertilization.

A simplified method for processing sperm obtained during microsurgical epididymal sperm aspiration (MESA) for use in in vitro fertilization.

Relationship of epididymal sperm antibodies to their in vitro fertilization capacity in men with congenital absence of the vas deferens

To test, using the immunobead binding technique, for the presence of antisperm antibodies on epididymal sperm, in epididymal fluid, and in serum of men with congenital absence of the vas deferens. To evaluate the in vitro fertilization (IVF) capacity of human epididymal sperm in the presence of antisperm antibodies. Prospective. At the time of oocyte insemination, sperm from the proximal caput epididymis or vasa efferentia were tested by direct immunobinding technique. The epididymal fluid and serum were tested by indirect immunobinding technique. Center for Reproductive Health, University of California-Irvine. Forty-five patients with congenital absence of the vas deferens participating in the microsurgical epididymal sperm aspiration and IVF program. Incidence of antisperm antibodies to epididymal sperm and their relationship with IVF results. Sixteen men (35%) tested positively to the direct immunobead test on epididymal sperm; 7 (16%) were positive in epididymal fluid and 13 (29%) were positive in serum. Five pregnancies (31%) occurred in the positive group of which two were from patients who had sperm binding of 100% for immunoglobulin (Ig)G (all over sperm surface) and 90% (midpiece, tail) and 50% (tail, tiptail), respectively, for IgA. Five pregnancies (18%) were obtained in the negative group. No statistical difference was observed in the overall fertilization rate between the two groups. Human epididymal sperm and epididymal fluid retrieved from men with congenital absence of the vas deferens can react positively to immunobead test. However, the presence of antisperm antibodies do not seem to impair the IVF capacity of epididymal sperm.