Free L-carnitine in human semen: its variability in different andrologic pathologies

Free L-carnitine was assayed in semen from patients with various andrologic diseases by an enzymatic-spectrophotometric method. Extremely low concentrations were found in semen from patients with agenesis of the vas deferens (31.8 +/- 18.8 nm/ml). Semen from men with vasectomies contains a higher concentration of free carnitine (105.0 +/- 8.1 nm/ml). When comparing these data with those of ten fertile control subjects (817.0 +/- 200 nm/ml), we assume that seminal free L-carnitine mainly originates from the epididymis. Semen from patients with azoospermia caused by testicular failure also contains a low carnitine concentration. In hypogonadotropic eunuchoids the gonadotropin treatment increased the low basal concentration. A correlation between semen carnitine content and sperm motility and number was also tested in 124 infertile patients. The results show a positive correlation between free L-carnitine and sperm count (r = 0.617; P less than 0.01), between free L-carnitine and sperm motility (r = 0.614; P less than 0.01), and between free L-carnitine and the number of motile spermatozoa per milliliter (r = 0.646; P less than 0.01).     

Varicocele is associated with abnormal retention of cytoplasmic droplets by human spermatozoa

OBJECTIVE: To determine whether varicocele is associated with retention of sperm cytoplasmic droplets in infertile men. DESIGN: Retrospective study.Setting: University infertility clinic. PATIENT(S): Nonazoospermic men with idiopathic (n = 69) and varicocele-associated infertility (n = 73), and 20 fertile controls presenting for vasectomy. INTERVENTION(S): None. MAIN OUTCOME MEASURES(S): Standard semen parameters and percentage of spermatozoa with cytoplasmic droplets on Papanicolaou smears. RESULT(S): No statistically significant differences were found between the fertile and infertile groups with respect to semen volume. Fertile controls had significantly greater mean percent sperm motility and normal morphology than infertile men. The mean percentage of sperm with residual cytoplasm was statistically significantly different in all three groups. Infertile men with varicocele had the highest percentage of sperm with cytoplasmic droplets, the next highest level being in men with idiopathic infertility and the lowest level in fertile controls (11.7 +/- 1.0, 8.1 +/- 0.9 and 3.2 +/- 0.4%, respectively, P<.0001). CONCLUSION(S): Our data show that idiopathic and even moreso, varicocele-related male infertility are conditions associated with impaired disposal of residual sperm cytoplasm by the testis and/or epididymis. These data provide a possible mechanism for the observed semen abnormalities and reduced fertility potential associated with varicocele and idiopathic male infertility.     

Analysis of aneuploidy in mini-percoll gradient centrifuged human sperm for intracytoplasmic sperm injection (ICSI) using fluorescence in situ hybridization

AIM: To study the aneuploidy rates of chromosomes 13, 18, 21, X and Y in Percoll gradient centrifuged sperm from infertile patients with male infertility factor treated by intracytoplasmic sperm injection (CSI) compared with healthy fertile donors and infertile patients with normal semen parameters. METHODS: This case-controlled study was conducted in a university hospital. Semen samples were obtained from three healthy fertile donors, eight infertile patients with normal semen parameters, and 18 infertile patients with male infertility factor. All samples were subjected to mini-Percoll gradient centrifugation before being processed through fluorescent in situ hybridization. The incidences of aneuploidy were compared using Chi-squared test. RESULTS AND CONCLUSIONS: A total of 64949 spermatozoa were analyzed. The disomy rates for chromosomes 13, 18, 21, and X or Y of sperm from patients with male infertility factor were 0.21%, 0.37%, 0.36% and 0.63%, respectively, whereas the diploidy rate was 0.17-0.23%. These incidences were higher than those from men with normal semen parameters. The result suggested that the embryos of patients with male infertility factor treated by ICSI are at increased risk of chromosome abnormalities.     

The role of DNA strand breaks in human spermatozoa used for IVF and ICSI

BACKGROUND: The objective of this study was to determine the incidence of spermatozoa with DNA strand breaks in four clinically different groups of infertile couples, and to correlate DNA damage with other semen analysis parameters, as well as fertilization rates and IVF outcome. METHODS: One group consisted of 75 men where the female partners had a tubal obstruction, Group A. Fifty sperm samples were collected from men in unexplained infertile couples, Group B. Fifty men with oligozoospermia and IVF made up Group C. Finally, 61 men with oligozoospermia and where ICSI was performed made up Group D. Sperm samples were assessed according to the WHO manual and for the presence of DNA strand breaks in spermatozoa. The study was blinded for the technician involved in the assessment of DNA strand breaks. IVF was carried out according to a long down regulation protocol using GnRH, FSH and hCG. Embryos were transferred on day 2 after fertilization with a maximum of three embryos. RESULTS: This study demonstrated a negative correlation between the proportion of spermatozoa having DNA strand breaks and the proportion of oocytes fertilized after IVF (p<0.01). Furthermore, the number of spermatozoa with DNA strand breaks was important for the pregnancy rate in the group of unexplained infertile couples. After ICSI no association was found between spermatozoa with DNA strand breaks and fertilization rates (p>0.05). CONCLUSION: DNA strand breaks in human spermatozoa impairs fertilization in both unexplained infertile couples and those with oligozoospermia and IVF. However, after ICSI, this impact of DNA strand breaks were not seen. This creates a specific indication and treatment for this new diagnosed group of otherwise unexplained infertile men.     

Sperm selection during ICSI treatments reduces single- but not double-strand DNA break values compared to the semen sample

PurposeTo detect a possible bias in sperm DNA fragmentation (SDF) testing when performed on semen samples or on those few spermatozoa selected for Intracytoplasmic Sperm Injection (ICSI) treatments.MethodsA multimethodological analysis of Single- and Double-Strand DNA Breaks (SSB and DSB, respectively) was performed through the Neutral Comet, the Alkaline Comet, the Sperm Chromatin Dispersion (SCD) and the Terminal deoxynucleotidyl transferase dUTP Nick End Labelling (TUNEL) assays. SDF was evaluated in (i) semen samples from 23 infertile patients (not achieving pregnancy or suffering recurrent miscarriage); (ii) samples after a Swim-up and (iii) spermatozoa microselected for ICSI (ICSI-S).ResultsThe analysis of 3217 ICSI-S revealed a significant reduction of SSB values compared to the Ejaculate and the Swim-up samples. On the contrary, DSB values were not reduced after any sperm selection method. The No-pregnancy group presented poorer semen parameters and higher SSB values. The Recurrent miscarriage group presented better semen parameters but also higher DSB values.ConclusionThe analysis of SDF on semen samples may not be fully representative of those few spermatozoa selected for ICSI. Since oxidative stress impairs sperm motility and causes SSB, selecting a motile sperm may intrinsically imply choosing a sperm not affected by this damage. DSB have an enzymatic origin which does not affect motility, making it difficult to select a sperm without this damage. Therefore, ICSI treatments could be effective in patients presenting high SSB values. Patients presenting high DSB values should expect bad ICSI results if this damage is not reduced through other specific methods.     

Novel associations between specific sperm morphological defects and leukocytospermia

OBJECTIVE: To examine the relationship between leukocyte concentrations in semen and sperm morphology in a group of infertile men and healthy fertile donors. DESIGN: A prospective clinical study. SETTING: Male infertility clinic at a tertiary care teaching hospital and a reproductive medicine unit at a Women's Hospital in the United Kingdom. PATIENT(S): Fifty-six infertile men and 13 healthy fertile sperm donors (control). INTERVENTION(S): Standard semen analysis, seminal leukocyte concentration, and the assessment of sperm morphology and sperm deformity index (SDI), applying Tygerberg's strict criteria. MAIN OUTCOME MEASURE(S): Granulocyte concentrations in semen, percentages of different sperm morphological abnormalities, and SDI scores. RESULT(S): Leukocyte concentrations were statistically significantly and negatively correlated with the proportion of sperm with damaged acrosomes, cytoplasmic droplet, tail defects, and SDI scores with normal and borderline morphology. The percentage sperm motility was significantly and negatively correlated with leukocytic concentration in semen. However, the leukocytic concentration was not significantly correlated with sperm concentration. CONCLUSION(S): This is the first study to report a significant positive correlation between leukocytospermia and sperm tail defects, acrosomal damage, and high SDI scores. These observations suggest that leukocytospermia is associated with compromised sperm structural integrity.     

Comparison of sex chromosome aneuploidy in spermatozoa of fertile men and those requiring ICSI treatment detected by fluorescence in situ hybridization

OBJECTIVE: To compare the frequencies of aneuploidy for chromosomes X, Y and 18 in spermatozoa of infertile and fertile males, using 3-color fluorescence in situ hybridization. METHODS: Twelve infertile patients who underwent intracytoplasmic sperm injection treatment at Queen's Medical Centre, Nottingham were studied. Three fertile men served as controls. Aneuploidy frequencies in both groups were compared using 2-sample t-tests. RESULTS: A total of 26,615 ad 93,649 cells were scored in the control and infertile groups respectively. The frequencies of diploidy, sex chromosome disomy and chromosome 18 disomy in the fertile (0.11, 0.28 and 0.11%) compared to the infertile males (0.05, 0.18 and 0.06%) were not statistically significantly different. CONCLUSION: Our preliminary data do not indicate an increased risk from paternal origin sex chromosome aneuploidies in ICSI. However, we recommend further investigations of the cytogenetic constitution of spermatozoa from severe male factor patients.     

Prognostic value of objective semen parameters in an in vitro fertilization program

Purpose: The basic semen parameters seem to have a limited predictive value in male fertility. Could other objective sperm analyses be helpful in the choice of the most adapted assisted procreation technique?Methods: This study concerns 78 infertile couples with insemination failures. For each semen, 21 objective parameters are analyzed in fresh semen and after sperm selection procedure. The 78 couples are then included in an IVF protocol and classified into two groups: fertile (at least one cleaved embryo is obtained) and infertile.Results: Using multiple variant discriminant factorial analysis, we have found nine nonconventional parameters which induce us to define two classes of semen. These two classes fit with the classification into fertile and infertile groups in 74.4% of the cases.Conclusions: So these parameters allow us to predict the chance of obtaining embryos during an IVF trial and to choose for each couple the most appropriate technique: IVF or ICSI.Key words: acrosome reaction, hyperactivated motility, in vitro fertilization, intracytoplasmic sperm injection, sperm kinetics     

The effects of sperm quality on embryo development after intracytoplasmic sperm injection

Purpose : To explore the possible relationship between sperm quality and embryo development, pregnancy and implantation rates, in patients undergoing intracytoplasmic sperm injection (ICSI). Methods : Fertilization and cleavage rates, quality of embryos, blastocyst development, pregnancy and implantation rates were analyzed in 1020 embryos from 219 couples undergoing first ICSI treatment cycle. The couples were allocated in five groups, according to semen parameters: Group 1: patients with normal semen parameters, Group 2: patients with mild oligo-astheno-teratozoospermia, Group 3: patients with severe oligo-astheno-teratozoospermia, Group 4: patients with obstructive azoospermia, Group 5: patients with non-obstructive azoospermia. Results : Fertilization and cleavage rates, quality of embryos as well as blastocyst development rates were significantly reduced, as semen quality decreased. However, no significant differences were observed in clinical pregnancy and implantation rates. Conclusion : Overall, a negative relationship was observed between semen quality and embryo development, even before activation of the embryonic genome, suggesting that sperm can affect embryogenesis from a very early stage.     

Effect of inseminated volume on intrauterine insemination

Purpose: Intrauterine insemination (IUI) is a method for the treatment of marital infertility involving the intrauterine or fallopian deposition of washed spermatozoa, depending on the amount of inseminated semen. In view of the divergent opinions about the inseminated volume, the objective of this study was to compare the two techniques (3.0 mL or 0.5 mL) in two groups of patients. Methods: We performed 164 cycles of ovulation induction followed by IUI. The patients were divided into two groups according to the technique used. Group low volume – 50 cycles and 0.5 mL of inseminated semen; Group high volume – 114 cycles and 3.0 mL of inseminated semen. The cycle was monitored on the basis of endometrial thickness and follicular development measured by transvaginal ultrasound. Human chorionic gonadotrophin (hCG) was administered in the presence of a follicle measuring 18 mm in mean diameter. The procedure was performed after sperm washing using a discontinuous PureSperm® gradient, 40 h later. Results: We obtained a similar clinical pregnancy rate for the two groups (14.0% for Group low volume and 15.7% for Group high volume). There was one abortion in each group. We detected no interference by any etiology of infertility or by the total motile recovered sperm with pregnancy rate. Conclusions: The results did not demonstrate superiority of one method over the other, with both therapeutic alternatives being satisfactory for the treatment of infertile couples.     

Analysis of sperm chromosomes in infertile males with teratozoospermia

OBJECTIVES: The aim of the study was to examine sperm chromosomes from infertile males with teratozoospermia. DESIGN: Basic research study MATERIALS AND METHODS: Spermatozoa were obtained from infertile males with teratozoospermia. Intracytoplasmic sperm injection was used to inject human spermatozoa into mouse oocytes in order to examine sperm chromosomes. RESULTS: Chromosomes of spermatozoa obtained from 6 infertile teratozoospermic and 1 fertile normozoospermic males were investigated. The mean frequency of structural chromosome aberrations in amorphous, motile spermatozoa was similar to that of morphologically normal sperm (9 vs. 7.7%). The structural aberrations found in amorphous, immotile spermatozoa reached 93% and revealed severity was significant. CONCLUSIONS: Teratozoospermia per se did not increase the frequency of structural chromosome aberrations in sperm. Severe chromosomal damage was revealed when immotile spermatozoa were injected into oocytes by ICSI.     

Les spermatozoïdes macrocéphales. Quels risques pour la fonction de reproduction ?

ObjectiveWe want to highlight the risk of infertility and failure of Assisted Reproductive Technologies due to the presence of macrocephalic spermatozoa (MS) in the sperm at rate equalling or superior to 20% in at least one semen analysis.Patients and methodsWe did a retrospective analysis of 19 infertile patients presenting MS at average rate between 14.3 and 49.7%. For each patient, at least one semen analysis showed a MS rate equal or superior to 20%. We did an automated analysis of the spermatozoa surface for 13 patients and a detailed analysis of the MS morphology in 18 patients. Thirteen couples benefited of one or more IVF with or without ICSI.ResultsThe semen analysis shows an impairment of one or more parameter of the sperm in all patients. Three morphological aspects for MS were highlighted: MS with irregular head, MS with regular head, and MS with multiple heads, with a dominance of irregular heads. The spermatozoa surface analysis shows a significant increase of the average surface and of the standard deviation (p < 0.0001). The average rate of pregnancies by transfer is decreased compared to usual rates in our laboratories (13% versus 28%).Discussion and conclusionWe want to sensitize biologist and clinical doctors to the existence of partial forms of this syndrome, which could be related to infertility with impaired sperm parameters and low pregnancy rates after FIV or ICSI.     

High sex chromosome aneuploidy and diploidy rate of epididymal spermatozoa in obstructive azoospermic men

Purpose: To evaluate the frequencies of sex chromosome aneuploidy and diploidy rate of epididymal spermatozoa from obstructive azoospermic men and its impact on intracytoplasmic sperm injection (ICSI) outcomes. Methods: Epididymal spermatozoa retrieved from 24 obstructive azoospermic men and ejaculated spermatozoa from 24 fertile donors were analyzed using triple color fluorescence in situ hybridization (FISH) techniques, in order to investigate the rates of diploidy and aneuploidy for chromosomes 18, X and Y. Results: Epididymal spermatozoa from obstructive azoospermic men had total sex aneuploidy, disomy 18, and diploidy rates significantly higher than ejaculated spermatozoa from normozoospermic fertile controls (1.44% vs. 0.14%, 0.11% vs. 0.02%, and 0.18% vs. 0.02%, respectively; p < 0.005). There were no statistically significant differences in ICSI outcomes between the patients who had high and low epididymal sperm aneuploidy rate. Conclusions: Epididymal spermatozoa from obstructive azoospermic patients had an elevated sex chromosome aneuploidy and diploidy rate. The increased frequency of chromosomal abnormalities did not have a direct effect on the ICSI outcome.     

Genetic aspects of monomorphic teratozoospermia: a review

Teratozoospermia is characterized by the presence of spermatozoa with abnormal morphology over 85 % in sperm. When all the spermatozoa display a unique abnormality, teratozoospermia is said to be monomorphic. Two forms of monomorphic teratozoospermia, representing less than 1 % of male infertility, are recognized: macrozoospermia (also called macrocephalic sperm head syndrome) and globozoospermia (also called round-headed sperm syndrome). Macrozoospermia is defined as the presence of a very high percentage of spermatozoa with enlarged head and multiple flagella. Meiotic segregation studies in 30 males revealed that over 90 % of spermatozoa were aneuploid, mainly diploid. Sperm DNA fragmentation studies performed in a few patients showed an increase in DNA fragmentation index compared to fertile men. Four mutations in the AURKC gene, a key player in meiosis and more particularly in spermatogenesis, have been found to be responsible for macrozoospermia. Globozoospermia is characterized by round-headed spermatozoa with an absent acrosome, an aberrant nuclear membrane and midpiece defects. The rate of aneuploidy of various chromosomes in spermatozoa from 26 globozoospermic men was slightly increased compared to fertile men. However, this increase was of the same order as that commonly found in infertile men with altered sperm parameters. The majority of the studies found that globozoospermic males had a sperm DNA fragmentation index higher than in fertile men. Mutations or deletions in three genes, SPATA16, PICK1 and DPY19L2, have been shown to be responsible for globozoospermia. Identification of the genetic causes of macrozoospermia and globozoospermia should help refine diagnosis and treatment of these patients, avoiding long and painful treatments. Elucidating the molecular causes of these defects is of utmost importance as intracytoplasmic sperm injection (ICSI) is very disappointing in these two pathologies.     

Clinical application of sperm-oocyte interaction tests in in vitro fertilization--embryo transfer and intracytoplasmic sperm injection programs

OBJECTIVE: To review the clinical value of sperm-oocyte interaction tests for the diagnosis and management of infertility by standard IVF or intracytoplasmic sperm injection (ICSI). DESIGN: Review of recent publications on relationships among sperm-oocyte interaction tests, sperm characteristics, and results of IVF and determination of frequency of defective sperm-oocyte interaction in infertile men. MAIN OUTCOME MEASURE(S): Fertilization rates with IVF, sperm characteristics, sperm-zona pellucida (ZP) binding, ZP-induced acrosome reaction (AR), and sperm-ZP penetration. RESULT(S): Sperm defects associated with low sperm-ZP binding or impaired ZP-induced AR and sperm-ZP penetration are the major causes of failure of fertilization when all or most oocytes from a couple do not fertilize in standard IVF. There is a high frequency of defective sperm-ZP interaction in men with oligozoospermia (<20 x 10(6)/mL) and severe teratozoospermia (strict normal sperm morphology < or =5%). Sperm morphology correlates with sperm-ZP binding, and sperm concentration correlates with ZP-induced AR in infertile men with sperm concentrations >20 x 10(6)/mL. Defective ZP-induced AR may cause infertility in up to 25% men with idiopathic infertility. These patients require ICSI despite the normal standard semen analyses. CONCLUSION(S): Sperm-oocyte interaction tests are useful for diagnosis of subtle sperm defects that cause infertility in men without severe abnormalities of semen analysis. Pre-IVF diagnosis of these sperm defects will assist in the clinical assignment of patients to treatment with either standard IVF or ICSI.     

Accuracy of sperm characteristics in predicting the in vitro fertilizing capacity of semen

Based on the results of in vitro fertilization (IVF) in 56 couples, the power was assessed of traditional sperm characteristics of native semen to discriminate between in vitro fertile and in vitro infertile semen. The number per ejaculate of spermatozoa with regular oval heads was the best discriminant, followed by the concentration of progressively motile spermatozoa. This contrasts with the in vivo fertilizing capacity, which depends mostly on the proportion and concentration of spermatozoa with rapid linear progression. The lower limit of sperm characteristics was assessed as the fifth percentile of in vitro fertile semen and was compared with the lower limit of semen of fertile men and of subfertile men who achieved spontaneous or treatment-related conception in vivo. It appeared that the semen quality needed for in vitro fertilization is inferior to that of fertile men but not remarkably different from that of subfertile men who achieved spontaneous conception during 1-year follow-up after consultation. If conventional methods for semen preparation are used, there seems to be no major advantage in favor of IVF for the treatment of male infertility due to sperm deficiency. An increased success rate may, however, be attained, thanks to improved techniques of semen collection, semen preparation, and oocyte insemination.     

Spermiogramm und Seminalplasma

Semen analysis is routinely used to evaluate the male partner in infertile couples. Unfortunately, sperm measurements that discriminate between fertile and infertile men are not well defined. Treatment decisions should therefore not be based exclusively on semen analysis, except for those cases with very poor sperm parameters. Treatments such as intra-uterine insemination (IUI) or intracytoplasmic sperm injection (ICSI) can usually be performed with sufficient pregnancy rates. In couples in which even ICSI fails, intracytoplasmatic, morphogically selected sperm injection (IMSI) seems to be promising. Collecting a semen sample with high quality is always important for male patients in assisted reproduction technology (ART) programs. Sperm quality can be improved using simple methods, such as modifying sexual abstinence or collecting semen samples at home. There is new evidence that the use of seminal plasma in ART treatment may improve endometrial receptivity and consequently implantation. Sexual intercourse around the time of embryo transfer also seems to improve the clinical outcome of ART.     

Assessment of male serum anti-Mullerian hormone as a marker of spermatogenesis and ICSI outcome

Objective.?To assess serum anti-Mullerian hormone (AMH) as a marker of spermatogenesis among fertile and infertile males, as well as its relation to ICSI outcome.

Methods.?A total of 77 male partners of infertile couples seeking infertility treatment were recruited for this study. They were classified according to the WHO criteria of semen analysis into three groups; azospermia, oligospermia, and normal. All participating patients had a serum assay of the level of AMH. Thirty-three couples out of the previously mentioned 77 couples underwent controlled ovarian stimulation and ICSI.

Results.?There were 41 patients with azospermia, 14 patients with oligospermia, and 22 patients with normal count. There was no significant difference among the three groups regarding the AMH levels. There was no significant correlation between the AMH levels from all patients and the sperm concentration (rho?=?0.03, p?=?0.82). Among patients who underwent ICSI, there was no significant correlation of the AMH with the age, sperm concentration, fertilisation percent or number of embryos. The age of male partners was significantly correlated with sperm concentration, fertilisation percent and the total number of embryos. In the logistic regression model used, serum AMH had no significant relation to clinical pregnancy.

Conclusion.?Male serum AMH levels are not indicative of spermatogenesis and cannot differentiate between fertile and infertile males. Serum AMH levels were not predictive of ICSI outcome as well.     

Sperm parameters in men with suspected infertility. Sperm characteristics, strict criteria sperm morphology analysis and hypoosmotic swelling test

OBJECTIVE: To determine the distribution of sperm abnormalities in a population of suspected infertile men presenting for the initial investigation of male factor infertility. STUDY DESIGN: Results obtained in the analysis of sperm viability, motility, conventional morphology (including 12 sperm anomalies), strict criteria sperm morphology analysis (SCSMA) and hypoosmotic swelling test (HOST) were compared in oligozoospermic (< 5.0, 5.1-10.0 and 10.1-20.0 x 10(6)/mL), normozoospermic (20.1-40.0, 40.1-100.0 and 100.1-250.0 x 10(6)/mL) and polyzoospermic (> 250.0 x 10(6)/mL) semen samples from 233 suspected infertile men. RESULTS: Percentage of sperm viability, category a and categories a plus b of sperm motility, oval-headed sperm, and normal-headed sperm according to SCSMA and HOST had a direct relationship with sperm counts (P < .001). Percentage of amorphous heads, pinheads, tapering and combined defects showed an inverse relationship with sperm counts (P < .001), whereas the percentage of large-headed sperm was highest in semen with > 40.0 x 10(6)/mL (P = .003) and of neck/midpiece defects was lowest in semen with < 10.0 x 10(6)/mL (P = .03). No significant differences were found in the percentage of small heads, double heads, round heads, partially elongated heads, cytoplasmic droplet and tail defects. Based on the cutoff points established previously for the sperm characteristics analyzed, normal values were found in semen with > 250.0 x 10(6)/mL (viability and motility), > 100.0 x 10(6)/mL (conventional morphology) and > 40.0 x 10(6)/mL (SCSMA and HOST). CONCLUSION: The incidence of defective spermatozoa is lowest in semen with the highest sperm count. However, sperm abnormalities that affect male fertility may be detected at any level of sperm density. The data indicate that an increase in any sperm abnormality should be regarded as a possible cause of decreased fertility.     

The role of DEFB126 variation in male infertility and medically assisted reproduction technique outcome

Research questionHuman DEFB126 is an important component of the glycocalyx of human spermatozoa. Beta-defensins play a primary role in male infertility due to their involvement in maturation and capacitation of spermatozoa. A 2-nt deletion of DEFB126 affects sperm function and so this study investigated the possible association between DEFB126 variants and its protein expression on medically assisted reproduction (MAR) technique outcome in Iranian infertile males.DesignThe presence of a 2-nt deletion of DEFB126, and its protein expression in spermatozoa, were investigated by standard polymerase chain reaction (PCR) sequencing and immunocytochemistry, respectively. MAR technique outcome according to clinical pregnancy rates was assessed in 277 Iranian males with unexplained infertility, including 139 patients who underwent intrauterine insemination (IUI) and 103 patients who underwent IVF/intracytoplasmic sperm injection (ICSI), as well as 35 infertile males who declined to use any MAR treatment. As the control group, 100 fertile males with a normal spermiogram were enrolled.ResultsThe 2-nt deletion of DEFB126 was significantly higher in infertile patients than controls (P ≤ 0.05). The presence of this deletion resulted in significantly lower clinical pregnancy rates following IUI (P ≤ 0.05); however, there were no differences in IVF/ICSI outcomes according to genotype. The protein expression in del/del males was also remarkably lower than that of the other genotypes.ConclusionsThis sequence variation of DEFB126 may impair male reproductive function and can be related to male infertility. Interestingly, males with the del/del genotype have a normal spermiogram; however, their spermatozoa are evidently functionally impaired, which can affect IUI treatment outcome, but not treatment by IVF/ICSI.