High implantation rate and consequently high pregnancy rate by in vitro fertilization-embryo transfer treatment in infertile women with antisperm antibody

Are sperm parameters able to predict the success of assisted reproductive technology? A retrospective analysis of over 22,000 assisted reproductive technology cycles

Background

An explosive increase in couples attending assisted reproductive technology has been recently observed, despite an overall success rate of about 20%–30%. Considering the assisted reproductive technology‐related economic and psycho‐social costs, the improvement of these percentages is extremely relevant. However, in the identification of predictive markers of assisted reproductive technology success, male parameters are largely underestimated so far.

Study design

Retrospective, observational study.

Objectives

To evaluate whether conventional semen parameters could predict assisted reproductive technology success.

Materials and methods

All couples attending a single third‐level fertility center from 1992 to 2020 were retrospectively enrolled, collecting all semen and assisted reproductive technology parameters of fresh cycles. Fertilization rate was the primary end‐point, representing a parameter immediately dependent on male contribution. Pregnancy and live birth rates were considered in relation to semen variables. Statistical analyses were performed using the parameters obtained according to the World Health Organization manual editions used for semen analysis.

Results

Note that, 22,013 in vitro fertilization and intracytoplasmic sperm injection cycles were considered. Overall, fertilization rate was significantly lower in patients with abnormal semen parameters compared to normozoospermic men, irrespective of the World Health Organization manual edition. In the in vitro fertilization setting, both progressive motility (p = 0.012) and motility after capacitation (p = 0.002) significantly predicted the fertilization rate (statistical accuracy = 71.1%). Sperm motilities also predicted pregnancy (p < 0.001) and live birth (p = 0.001) rates. In intracytoplasmic sperm injection cycles, sperm morphology predicted fertilization rate (p = 0.001, statistical accuracy = 90.3%). Sperm morphology significantly predicted both pregnancy (p < 0.001) and live birth (p < 0.001) rates and a cut‐off of 5.5% was identified as a threshold to predict clinical pregnancy (area under the curve = 0.811, p < 0.001).

Discussion

Interestingly, sperm motility plays a role in predicting in vitro fertilization success, while sperm morphology is the relevant parameter in intracytoplasmic sperm injection cycles. These parameters may be considered reliable tools to measure the male role on ART outcomes, potentially impacting the clinical management of infertile couples.

Success rates of in vitro fertilization versus intracytoplasmic sperm injection in men with serum anti-sperm antibodies: a consecutive cohort study

Antisperm antibodies (ASAs) are assumed to be a possible causative factor for male infertility, with ASAs detected in 5%–15% of infertile men but in only 1%–2% of fertile ones. It remains unclear whether ASAs have an adverse effect on the outcome of in vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI). This study investigated differences in the rates of fertilization, pregnancy, and live births associated with serum ASA-positive and ASA-negative men following IVF or ICSI. Five hundred and fifty-four consecutive infertile couples undergoing IVF (n = 399) or ICSI (n = 155) were included. The two-sample two-sided t-test and Chi-square or Fisher's exact test was used for statistical analysis. Lower rates of fertilization (41.7% vs 54.8%, P = 0.03), good embryos (18.9% vs 35.2%, P = 0.00), pregnancy (38.5% vs 59.4%, P = 0.00), and live births (25.8% vs 42.5%, P = 0.00) were observed in men of the IVF group with a positive serum ASA than in those with a negative ASA. ASA positivity/negativity correlated with pregnancy rates (P = 0.021, odds ratio [OR]: 0.630, 95% confidence interval [CI]: 0.425–0.932) and live birth rates (P = 0.010, OR: 1.409, 95% CI: 1.084–1.831) after controlling for the female serum follicle-stimulating hormone level and the couple's ages at IVF. Women coupled with ASA-positive men had lower live birth rates with IVF than with ICSI (25.8% and 47.4%, respectively; P = 0.07). Women coupled with ASA-positive men had lower rates of pregnancy and live births following IVF than those coupled with ASA-negative men but had a similar outcome with ICSI.

Antisperm antibodies and conception

Sperm have been known to be antigenic for more than a century. There is a strong body of evidence that in humans and in other species at least some antibodies that bind to sperm antigens can cause infertility. Therefore, these antibodies are of interest today for two practical reasons. Firstly, the association of the antibodies with infertility means that they must be detected and then the couples treated appropriately. Secondly, because these antibodies can induce infertility they have the potential to be developed for contraceptive purposes in humans and also for the control of feral animal populations.

Sperm-zona pellucida interaction and immunological infertility

Immune reactions against gametes appear to be physiologically important for the maintenance of homeostasis in reproduction. In contrast, aberration of the immune homeostasis might give rise to 'immunological infertility'. Antisperm antibodies cause infertility by blocking fertilization. The mechanism can be explained as inhibiting the acrosome reaction of sperm by their blocking effect on capacitation through inhibiting an increase of fluidity of the sperm membrane. Autoantibodies against zona pellucida also cause infertility by blocking sperm-zona pellucida interaction, though the definitive mechanism has not been elucidated. Pretreatment of spermatozoa with D-mannnose completely inhibited sperm penetration through, but not binding to, the zona pellucida. Furthermore, very rapid kinetics between sperm extracts and D-mannnose by a BIAcore apparatus suggest that a D-mannose ligand of the sperm surface is easy to bind to and dissociate from a D-mannose residue in the sperm receptor site on the zona pellucida. Thus, D-mannnose on the human zona pellucida might be an essential molecule acting as a second sperm receptor, through which sperm penetrate into the zona pellucida. Because these antibodies appear to not cause any deleterious clinical symptoms, sperm and zona pellucida antigens are promising candidates in the development of an immunocontraceptive. (Reprod Med Biol 2006; 5: 95-104).

Effects of in vivo exposure to eggs with sperm-immobilizing antibodies in follicular fluid on subsequent fertilization and embryo development in vitro

Aims:  It has been shown that supplementation of patients' sera that contains sperm-immobilizing antibodies results in failure of fertilization and embryo development in vitro. The present study was carried out to investigate if exposing retrieved eggs to a high number of sperm-immobilizing antibodies in the follicular fluid (FF) in vivo affected subsequent fertilization and embryo development in vitro, even if they were washed with an antibody-free culture medium. Methods:  Patients' sera and their FF were collected in 15 in vitro fertilization-embryo transfer (IVF-ET) or intracytoplasmic sperm injection-embryo transfer (ICSI-ET) treatment cycles from 11 infertile women with sperm-immobilizing antibodies in their sera. Quantitative sperm-immobilizing antibody titers (SI₅₀ titers) in the sera and FF were evaluated. The fertilization rate, good-quality embryo rate and implantation rate by IVF-ET were compared between infertile patients having higher (10≤) SI₅₀ titers and lower (<10) SI₅₀ titers in their FF. Results:  There was a significant correlation in the SI₅₀ titers between the patients' sera and their FF (P < 0.0001). After thoroughly washing the collected eggs in culture medium without the patient's serum before IVF, there was no difference in the fertilization rate in the patients with high (10≤) and low (<10) SI₅₀ titers in their FF (P = 0.62). However, the good-quality embryo rate in the patients with a high SI₅₀ titer was significantly lower than patients with a low antibody titer (P < 0.05). There was no significant difference in the implantation rate between the two groups (P = 0.33). Conclusions:  Similar amounts of sperm-immobilizing antibodies existed in the patients' FF and in their sera. ICSI did not seem to be necessary in patients having the antibodies if their sera were not supplemented in the culture media. Even with careful manipulation of eggs, it might be suggested that the harmful effects of sperm-immobilizing antibodies on embryo development cannot be completely avoided, especially in patients with high SI₅₀ titers in the FF. (Reprod Med Biol 2006; 5: 137-143).

Effects of in vivo exposure to eggs with sperm-immobilizing antibodies in follicular fluid on subsequent fertilization and embryo development in vitro

Aims:  It has been shown that supplementation of patients' sera that contains sperm-immobilizing antibodies results in failure of fertilization and embryo development in vitro. The present study was carried out to investigate if exposing retrieved eggs to a high number of sperm-immobilizing antibodies in the follicular fluid (FF) in vivo affected subsequent fertilization and embryo development in vitro, even if they were washed with an antibody-free culture medium. Methods:  Patients' sera and their FF were collected in 15 in vitro fertilization-embryo transfer (IVF-ET) or intracytoplasmic sperm injection-embryo transfer (ICSI-ET) treatment cycles from 11 infertile women with sperm-immobilizing antibodies in their sera. Quantitative sperm-immobilizing antibody titers (SI₅₀ titers) in the sera and FF were evaluated. The fertilization rate, good-quality embryo rate and implantation rate by IVF-ET were compared between infertile patients having higher (10≤) SI₅₀ titers and lower (<10) SI₅₀ titers in their FF. Results:  There was a significant correlation in the SI₅₀ titers between the patients' sera and their FF (P < 0.0001). After thoroughly washing the collected eggs in culture medium without the patient's serum before IVF, there was no difference in the fertilization rate in the patients with high (10≤) and low (<10) SI₅₀ titers in their FF (P = 0.62). However, the good-quality embryo rate in the patients with a high SI₅₀ titer was significantly lower than patients with a low antibody titer (P < 0.05). There was no significant difference in the implantation rate between the two groups (P = 0.33). Conclusions:  Similar amounts of sperm-immobilizing antibodies existed in the patients' FF and in their sera. ICSI did not seem to be necessary in patients having the antibodies if their sera were not supplemented in the culture media. Even with careful manipulation of eggs, it might be suggested that the harmful effects of sperm-immobilizing antibodies on embryo development cannot be completely avoided, especially in patients with high SI₅₀ titers in the FF. (Reprod Med Biol 2006; 5: 137-143).

Sperm-zona pellucida interaction and immunological infertility

Immune reactions against gametes appear to be physiologically important for the maintenance of homeostasis in reproduction. In contrast, aberration of the immune homeostasis might give rise to 'immunological infertility'. Antisperm antibodies cause infertility by blocking fertilization. The mechanism can be explained as inhibiting the acrosome reaction of sperm by their blocking effect on capacitation through inhibiting an increase of fluidity of the sperm membrane. Autoantibodies against zona pellucida also cause infertility by blocking sperm-zona pellucida interaction, though the definitive mechanism has not been elucidated. Pretreatment of spermatozoa with D-mannnose completely inhibited sperm penetration through, but not binding to, the zona pellucida. Furthermore, very rapid kinetics between sperm extracts and D-mannnose by a BIAcore apparatus suggest that a D-mannose ligand of the sperm surface is easy to bind to and dissociate from a D-mannose residue in the sperm receptor site on the zona pellucida. Thus, D-mannnose on the human zona pellucida might be an essential molecule acting as a second sperm receptor, through which sperm penetrate into the zona pellucida. Because these antibodies appear to not cause any deleterious clinical symptoms, sperm and zona pellucida antigens are promising candidates in the development of an immunocontraceptive. (Reprod Med Biol 2006; 5: 95-104).

Impact of assisted hatching on the outcome of intracytoplasmic sperm injection: a prospective, randomized clinical trial and pregnancy follow-up

OBJECTIVE

To evaluate the overall effect of assisted hatching (AH) on the implantation, pregnancy, and live birth rates in women undergoing intracytoplasmic sperm injection (ICSI) cycles; and to determine the effect of AH on the cytogenetic outcome (chromosomal constitution) of pregnancy.

DESIGN

Prospective, randomized study.

SETTING

Academic research environment.

PATIENT(S)

A total of 172 couples were enrolled in the study.

INTERVENTION(S)

Assisted hatching was carried out on day-3 ICSI embryos.

MAIN OUTCOME MEASURE(S)

Implantation, clinical pregnancy, and live birth rates; cytogenetic analysis of abortuses and umbilical cord blood samples from newborns.

RESULT(S)

Biochemical, clinical, and ongoing pregnancy rates were not significantly different between the AH and control groups. The implantation rate was higher in the AH group than in the control group (16% vs. 8%), especially in women aged > or =35 years. Postnatal umbilical cord blood samples were collected and cytogenetically analyzed from 39 live births (20 from the AH group, 19 from the control group). Two abnormal karyotypes were found (one AH, one control). There were seven spontaneous losses during the study interval. Six of the abortuses underwent cytogenetic study (five AH, one control), and four were found to have an abnormal karyotype (three AH, one control).

CONCLUSION

We found that AH improves implantation rates of ICSI cycles and seems to be most effective in women aged > or =35 years. A larger sample size is needed to determine whether AH improves the take-home-baby rate. Assisted hatching did not affect the rate of chromosomal abnormalities in live births in this study.

Modalities for treatment of antisperm antibody mediated infertility: novel perspectives

Immunoinfertility because of antisperm antibodies (ASA) is an important cause of infertility in humans. The incidence of ASA in infertile couples is 9-36% depending on the reporting center. Early claims regarding the incidence and involvement of ASA in involuntary infertility were probably overemphasized, which has resulted in subsequent confusion, doubt, and underestimation of their clinical significance. No immunoglobulin that binds to sperm should be called an antisperm antibody in a strict sense unless it is directed against a sperm antigen that plays a role in fertilization and fertility. ASA directed against the fertilization-related antigens are more relevant to infertility than the immunoglobulins that bind to sperm associated antigens. Several methods have been reported for treatment of immunoinfertility. These include: immunosuppressive therapies using corticosteroids or cyclosporine; assisted reproductive technologies such as intrauterine insemination, gamete intrafallopian transfer, in vitro fertilization, and intracytoplasmic sperm injection; laboratory techniques such as sperm washing, immunomagnetic sperm separation, proteolytic enzyme treatment, and use of immunobeads. Most of the available techniques have side effects, are invasive and expensive, have low efficacy, or provide conflicting results. Recent findings using defined sperm antigens that have a role in fertilization/fertility have provided animal models and innovative novel perspectives for studying the mechanism of immunoinfertility and possible modalities for treatment. The better understanding of local immunity and latest advances in hybridoma and recombinant technologies, proteomics and genomics leading to characterization of sperm antigens relevant to fertility will help to clarify the controversy and to establish the significance of ASA in infertility.

Effects of sera from infertile women with sperm immobilizing antibodies on fertilization and embryo development in vitro in mice

PROBLEM

This study was performed to investigate if patients' sera with anti-human sperm antibodies show inhibitory effects on in vitro fertilization (IVF) and embryo development in mice.

METHOD OF STUDY

Patients' sera were collected from eight infertile women having sperm immobilizing antibodies and 17 infertile women without the antibodies. Male ICR mice and female F1 mice (BALB/c X C57BL/6J) were used. In mouse IVF, pre-incubated sperm were cultured in the medium containing patient's serum with or without sperm immobilizing antibodies, or bovine serum albumin (BSA) as a control. The fertilization rates and the incidences of blastocyst formation were compared.

RESULTS

A mouse sperm immobilization test was established. Five (62.5%) of eight serum samples with sperm immobilizing antibodies and nine (52.9%) of 17 serum samples without the antibodies showed sperm immobilizing activities in mice. There was no significant difference between the two groups. Five sera with sperm immobilizing activities in human and mice, and five sera without sperm immobilizing activities in human or mice were used for the further experiments. The fertilization rates in BSA, patient's serum with sperm immobilizing antibodies, and that without the antibodies were 82.5% (746/904), 43.6% (508/1165), and 64.5% (669/1037), respectively. There were significant differences between the groups. The incidences of blastocyst formation were 59.9% (447/746), 31.7% (161/508), and 47.7% (319/669), respectively. There were also significant differences between the groups.

CONCLUSIONS

Some of the patient's serum with and without sperm immobilizing antibodies could immobilize sperm with complement. However, as compared with control, sera with sperm immobilizing activities against human and mouse sperm significantly blocked IVF and inhibited embryo development in mice. Further studies are required to investigate the mechanisms of the blocking effects of antisperm antibodies on fertilization and embryo development using the mouse model.

Sperm immobilizing antibodies in the sera of infertile women cause low fertilization rates and poor embryo quality in vitro

PROBLEM

The effects of sperm immobilizing antibodies in the sera of infertile women on fertilization and embryo quality in vitro were investigated.

METHOD OF STUDY

Before the introduction of sperm immobilization test (SIT) as a routine test for female infertility, 85 oocytes were collected in nine in vitro fertilization (IVF) cycles from four infertile women who were afterward found having had sperm immobilizing antibodies in their sera and the oocytes were inseminated with swim-up sperm in a medium containing the patient's serum. Fifty oocytes were collected in five IVF cycles from five infertile women possessing the antibodies in their sera and the oocytes were inseminated with swim-up sperm in a medium supplemented with human serum albumin (HSA).

RESULTS

In the former group, 41 of 85 oocytes were fertilized, giving a fertilization rate of 48.2%. In the latter group, 43 of 50 oocytes were fertilized, giving a fertilization rate of 86.0%. There was a significant difference of the fertilization rate between the groups (P < 0.0001). Embryo quality was assessed by the Veeck's classification. The grade 1 and grade 2 embryos were considered good quality. Using this classification, 16 (39.0%) of 41 embryos incubated in the medium containing the patient's serum were good quality, while 34 (79.1%) of 43 embryos incubated in the medium supplemented with HSA were good quality. There was also a significant difference between the groups (P = 0.0003).

CONCLUSIONS

These findings might indicate that sperm immobilizing antibodies in the sera of infertile women cause low fertilization rates and poor embryo quality in vitro. It is suggested that SIT in the sera of infertile women should be performed at least before proceeding IVF. The manipulation of gametes and embryos from patients having sperm immobilizing antibodies should be carefully carried out especially to avoid contaminating patient's serum and follicular fluid in the culture medium in order to have a better IVF result.

Conventional in-vitro fertilisation versus intracytoplasmic sperm injection for the treatment of non-male-factor infertility: a randomised controlled trial

BACKGROUND

Intracytoplasmic sperm injection (ICSI) is a more invasive option than conventional in-vitro fertilisation (IVF), which can be successful even when semen characteristics are poor. Reports of higher fertilisation rates after ICSI suggest that this technique may be better than the conventional method for all couples seeking IVF. We undertook a multicentre randomised controlled trial comparing clinical outcome after ICSI or traditional IVF in couples with non-male-factor infertility.

METHODS

415 eligible and consenting couples at four UK centres were randomly assigned IVF or ICSI (total 435 treatment cycles: IVF 224; ICSI 211). Usual clinical and laboratory protocols for the two treatment procedures were followed in each of four participating centres. The primary outcome was the implantation rate (number of gestation sacs per embryo replaced expressed as a percentage). Secondary outcomes were pregnancy and fertilisation rates associated with each treatment. Analyses were by intention to treat.

FINDINGS

The implantation rate was higher in the IVF group than in the ICSI group (95/318 [30%] vs 72/325 [22%]; relative risk 1.35 [95% CI 1.04-1.76]). The pregnancy rate per cycle was also higher after IVF (72 [33%] vs 53 [26%]; 1.17 [0.97-1.35]). Mean associated laboratory time was significantly shorter with IVF than with ICSI (22.9 [SD 12.1] vs 74.0 [38.1] min; 95% CI for difference 45.6-56.6).

INTERPRETATION

ICSI offers no advantage over IVF in terms of clinical outcome in cases of non-male-factor infertility. Our results support the current practice of reserving ICSI only for severe male-factor problems.

Specific cytotoxicity of antibody to YAL-198, a sperm antigen peptide, to murine zygote

Active immunization with the peptide segments rSMP-230 and YAL-198, corresponding to the hydrophilic extracellular domain of two human sperm antigens (rSMP-B and YWK-II, respectively), reduced fertility in female rats by different mechanisms. The anti-rSMP-230 antibody interferes with human and murine fertilization, and the anti-YAL-198 antibody blocks the development of mouse embryos. The authors examined in vitro at which stage the antibodies to rSMP-230 and YAL-198 were cytotoxic to murine embryos up to morula/blastocyst stage. Anti-rSMP-230 antibody was not cytotoxic to any stages. On the other hand, the anti-YAL-198 antibody arrested the growth of embryos at the 2-cell stage but not at more advanced developmental stages. When the anti-YAL-198 antibody was used, spotty staining was observed only on the surfaces of embryos that had arrested at the 2-cell stage. Unstained embryos, however, continued to develop normally. In contrast, the anti-rSMP-230 antibody stained murine sperm but failed to stain murine ova and embryos. The present results suggest that the human sperm components rSMP-B and YWK-II play important roles in sperm-egg interaction and early development of the embryo, respectively.

Quality of embryo does not affect the implantation rate of IVF-ET in infertile women with antisperm antibody

OBJECTIVE

To determine whether low quality score of embryos and advanced maternal age affect the implantation rate in infertile women with sperm-immobilizing antibody.

DESIGN

A retrospective study.

SETTING

The IVF Unit of the Department of Obstetrics and Gynecology at Tokushima University Hospital.

PATIENT(S)

Four infertile groups were studied: 20 women with sperm-immobilizing antibodies; 169 with tubal; 129 with male factor; and 72 with unexplained etiology.

INTERVENTION(S)

All women were hyperstimulated with GnRH analogue and scheduled ovarian stimulation with FSH and hMG for oocyte retrieval.

MAIN OUTCOME MEASURE(S)

Relationship of quality of transferred embryos, implantation rate and maternal age among four groups of infertile couples.

RESULT(S)

In the antisperm group, the fertilization rate (57.6%) and mean (+/- SD) score of transferred embryos (5.4+/-1.9) were significantly lower than those in the tubal group (72.4% and 6.2+/-1.9, respectively). However, the implantation rate in the antisperm group (23.6%) was significantly higher than those in other three groups (tubal, 8.6%; male factor, 9.5%; unexplained, 7.6%). With advancing maternal age, the implantation rate decreased in the three comparative groups. In contrast, the implantation rate in the antisperm group did not decrease with advancing maternal age.

CONCLUSION(S)

Women with antisperm antibodies have several disadvantages to overcome in order to achieve successful IVF-ET, such as a low fertilization rate and poor quality of transferred embryos. However, a high implantation rate was observed in this group, even in women at advanced age. The occurrence of a cellular or humoral immune reaction against sperm may augment the uterine receptivity for the implantation of fertilized ova or blastocyst.

Identification of the human sperm protein that interacts with sperm-immobilizing antibodies in the sera of infertile women

OBJECTIVE

To identify the target antigen of sperm-immobilizing antibodies present in the circulation of infertile women.

DESIGN

Laboratory research.

SETTING

Academic research laboratory.

PATIENT(S)

Twenty-nine infertile women with sperm-immobilizing antibodies, 22 infertile women with other disorders, and 20 fertile women.

INTERVENTION(S)

Titers of antibodies to the sperm protein, rSMP-B, were determined by ELISA using as substrate the synthetic peptide segment (rSMP-230) that corresponds with the hydrophilic domain of rSMP-B. Tests for sperm immobilization and zona pellucida penetration were performed using the human IVF system.

MAIN OUTCOME MEASURE(S)

Human sera with sperm-immobilizing activity were assayed for the presence of antibodies to rSMP-230. Polyclonal antibodies to rSMP-230 were assessed for the same biologic activities as sperm-immobilizing antibodies.

RESULT(S)

Antibodies to rSMP-230 were detected in 10 (34%) of 29 sera obtained from women with immunologic infertility. In contrast, only one serum sample (2%) from women without sperm-immobilizing activity had a low titer of antibodies to rSMP-230. Polyclonal antibodies to rSMP-230 completely immobilized human sperm in the presence of complement and blocked sperm penetration across the zona pellucida.

CONCLUSION(S)

The human sperm protein, rSMP-B, probably is the target antigen of sperm-immobilizing antibodies.

Binding of human secretory leukocyte protease inhibitor in uterine cervical mucus to immunoglobulins: pathophysiology in immunologic infertility and local immune defense

OBJECTIVE

To identify an Fc receptor-like molecule in human cervical mucus.

DESIGN

Controlled experimental laboratory study.

SETTING

Department of Obstetrics and Gynecology, School of Medicine, University of Tokushima.

PATIENT(S)

Women undergoing treatment for infertility.

INTERVENTION(S)

Sodium dodecyl sulfate-polyacrylimide gel electrophoresis and Western blot were used for analysis.

MAIN OUTCOME MEASURE(S)

A water-insoluble protein with immunoglobulin-binding activity was purified from human cervical mucus by ammonium sulfate fractionation. The initial 21 amino acids of the N-terminus of the immunoglobulin-binding protein were determined and analyzed in a computer search for homology.

RESULT(S)

The purified fraction contained a 15-kd protein that binds immunoglobulin A, immunoglobulin M, and all subclasses of human immunoglobulin G as determined by Western blot analysis. The amino acid sequence of the N-terminus is identical to that of secretory leukocyte protease inhibitor. The capacity of secretory leukocyte protease inhibitor to bind immunoglobulins was confirmed by Western blot analysis.

CONCLUSION(S)

A component in human cervical mucus capable of binding immunoglobulins was identified as secretory leukocyte protease inhibitor. The capacity to bind immunoglobulins is a unique property of the protein, providing additional support for the contention that it plays an important physiologic role in local tissue defense mechanisms. It also is involved in the pathogenesis of immunologic infertility by trapping sperm in the cervical mucus.

Antisperm antibodies: etiology, pathogenesis, diagnosis, and treatment

OBJECTIVE

To critically review the English-language literature and describe the current diagnosis, prevalence, etiology, and treatment of antisperm antibodies (ASA).

DESIGN

A comprehensive literature search of the English-language literature published between 1966 and December 1997 was performed on MEDLINE. Articles were also located via bibliographies of published works.

RESULT(S)

Data were excerpted from articles identified by MEDLINE search. The diagnosis, prevalence, etiology, and treatment of ASA are described.

CONCLUSION(S)

There is sufficient evidence that ASA impair fertility in couples with unexplained infertility. A number of different methodologies are available, which may be used in their detection. However, in many cases, test interpretation is subjective. Although there is not enough evidence to support systemic treatment for ASA, application of a variety of assisted reproductive technologies improves outcome.

Do autoantibodies to sperm reduce fecundity? A mini-review in historical perspective

PROBLEM

The paradox that early studies of antisperm antibodies in men showed a strong correlation between titers of circulating antibodies (essentially immunoglobulin [Ig] G) and reduction in conception rates, whereas more recent studies have indicated that the antifertility effect is mainly (or exclusively?) associated with IgA antibodies, impairing sperm migration through cervical mucus, was studied.

METHOD OF STUDY

Relevant literature focusing on antibodies on ejaculated sperm was analyzed.

RESULTS

Direct mixed antiglobulin reaction (MAR) and immunobead-binding tests are excellent and sensitive techniques for demonstrating antibodies of the IgG and IgA classes on sperm, and they have revealed that IgA antibodies are, with very rare exceptions, found only when IgG antibodies are also present. However, these tests tell little about the amounts of antibodies present, and attempts to measure quantitatively the amounts of Ig on sperm have indicated higher levels of IgA than IgG (despite the strongest MAR reactivities for IgG).

CONCLUSIONS

The patients with high levels of IgA to their sperm are mainly men with strong immune responses and, therefore, also high antibody titers in serum. Apparently, the locally produced IgA antibodies reach the sperm and occupy the binding sites before the main bulk of IgG reaches the seminal compartment with the prostatic fluid.

Semen analysis and antisperm antibody

Evaluation of the fertilizing potential of sperm is an important procedure in in vitro fertilization and embryo transfer (IVF-ET) clinic, in order to avoid performing invalid conventional IVF-ET or unnecessary intracytoplasmic sperm injection (ICSI). However, none of the standard semen parameters are reliable indices in predicting IVF outcome. The test examining sperm-zona interaction is the best present method, though the short supply of the human zona component should be solved. IVF-ET treatment is useful for pregnancy in women having sperm immobilizing antibodies because it avoids exposing sperms to antibodies that block fertilization. ICSI should be used in immunologically infertile men diagnosed by specific method to demonstrate the in vivo exposure of sperms to antisperm autoantibodies that block fertilization.

Effects of sperm immobilizing antibodies on pregnancy outcome in infertile women treated with IVF-ET

PROBLEM

Since it was found that anti-sperm antibodies could impair in vitro development of fertilized eggs in the presence of complement in rats, the effects of sperm immobilizing antibodies on human pregnancy were examined in infertile women treated with IVF-ET.

METHODS

The pregnancy outcomes of 143 ET cycles in 58 infertile women with sperm immobilizing antibodies and 363 ET cycles in patients with tubal infertility as control were compared. Diagnosis of chemical pregnancy was done when the urinary hCG level had risen over 50 IU/L but a gestational sac could not be demonstrated later. Antibody titers of sperm immobilizing antibodies (SI50 units) were measured by a quantitative sperm immobilization test.

RESULTS

33 (23.1%) of 143 cycles in the patients with sperm immobilizing antibodies and 56 (15.4%) of 363 cycles in the control patients were diagnosed as pregnancy. The pregnancy rates were significantly higher in the former than in the latter (P < 0.05). In the patients with sperm immobilizing antibodies, 12 (36.4%) were chemical pregnancies, 5 (15.2%) were clinical abortions, and 16 (48.5%) had deliveries. In the control group, 18 (32.1%) were chemical pregnancies, 10 (17.9%) were clinical abortions including ectopic pregnancies and 28 (50.0%) had deliveries. There was no significant differences in each category. When the SI50 titers at the time of conception were considered, chemical pregnancy rates were 22.2% (4/18) in patients with SI50 titers below 10 units, but those in patients with SI50 titers above 10 were 50.0% (5/10) and above 100 were 60.0% (3/5), respectively, (P > 0.05). In four of five patients who had both chemical and clinical pregnancies, the SI50 titers at the time of conception were higher in the chemical pregnancy cycles than in the clinical pregnancy cycles.

CONCLUSIONS

Though the pregnancy rates were significantly higher in the patients with sperm immobilizing antibodies as compared to those with tubal infertility, chemical pregnancy rates were also higher in the patients with higher sperm immobilizing antibody titers. These results suggest that sperm immobilizing antibodies may cause the damage of early development of human embryos in vivo in the small number of patients with a high titer of the antibodies.