Impact of weight loss on sperm DNA integrity in obese men

The objective of the study was to determine whether weight loss in obese men improves their fertility with respect to DNA fragmentation index and morphology. Collected fertility parameters included DFI and morphology. Body mass index (BMI) was calculated for all patients with comparisons to their fertility parameters before and after weight loss using paired t test and chi‐square tests. The mean BMI was significantly higher in group 1, before weight loss (33.18 kg/m²), than in group 2, after weight loss (30.43 kg/m²). Overall, 53.3% of men had DFI <20% while 43.8% had a DFI between 20% and 40%, and 2.9% of men had DFI >40%. The mean DFI of participants was higher before weight loss (20.2%) and had improved significantly after weight loss (17.5%) (p = <.001). The weight loss had significant positive correlation with percentage of DFI. There was a significant improvement in morphology after weight loss (p = <.05). In one of the largest cohorts of male fertility and obesity, DFI and morphology demonstrated significant relationship with adiposity, possibly contributing to subfertility in this population.     

Evaluation of sperm DNA fragmentation and chromatin structure in infertile men with immotile short-tail sperm defect

Teratozoospermia is characterised by the presence of spermatozoa with abnormal morphology. One of the morphological disorders that lead to male infertility is immotile short-tail sperm (ISTS) defect. In this study, we evaluated the levels of chromatin packing and DNA fragmentation in patients with immotile short-tail sperm defect. Semen samples were obtained from 31 infertile men with ISTS as case group and 31 normozoospermic men as a control group. Protamine status was evaluated using chromomycin A3 (CMA3) staining and sperm DNA fragmentation assessed by sperm chromatin structure assay (SCSA) and terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate biotin nick-end labelling (TUNEL). The percentage of positive CMA3 spermatozoa was significantly higher in patients’ samples (22.6 ± 6.9) compared with controls (16.3 ± 4.2) (p < .05) and also mean (±SD) of sperm DNA fragmentation was significantly higher in patients compared with controls, as measured by TUNEL assay (10.45 ± 4.60 vs. 7.03 ± 2.86, p < .05) and SCSA (24.80 ± 13.1 vs. 15.2 ± 7.2, p < .05). According to our study, sperm DNA fragmentation and chromatin packing abnormality are significantly higher in the ISTS samples compared with normal samples. A possible explanation for this relationship is that sperm chromatin condensation and sperm flagellum formation occur during the same phase of spermatogenesis.     

Effects of obesity on sperm retrieval,early embryo quality and clinical outcomes in men with nonobstructive azoospermia undergoing testicular sperm aspiration‐intracytoplasmic sperm injection cycles

The objective of this study was to assess the effects of body mass index (BMI) on sperm retrieval, early embryo quality and clinical outcomes in patients with nonobstructive azoospermia (NOA) undergoing testicular sperm aspiration‐intracytoplasmic sperm injection (TESA‐ICSI). A total of 3,005 infertile couples were evaluated between January 2010 and June 2017, including 1585 normal‐weight (BMI < 25 kg/m²), 847 overweight (BMI 25–29.99 kg/m²) and 573 obese (BMI ≥ 30 kg/m²) patients. We found no significant relationship between BMI and sperm retrieval rate (22.4%, 24.3% and 25.1%, p = 0.327) or sperm motility. Among the 705 patients with NOA who underwent TESA‐ICSI cycles, obese individuals had lower T levels and higher E2 levels than normal‐weight and overweight individuals. However, there were no significant differences in other male hormones (follicle stimulating hormone [FSH], luteinizing hormone [LH], or prolactin [PRL]) among the groups. We also found that the sperm parameters, embryo quality and clinical outcomes of patients with NOA undergoing TESA‐ICSI were not influenced by high BMI levels. In conclusion, this study demonstrated a lack of obvious effects of obesity on sperm retrieval, early embryo quality and clinical outcomes in infertile men undergoing TESA‐ICSI cycles, although T and E2 levels were affected.     

Apoptotic sperm biomarkers and the correlation between conventional sperm parameters and clinical characteristics

The principal aim of this retrospective study was to examine the relationship between sperm apoptotic biomarkers and the patient's biclinical characteristics, the conventional sperm parameters and the results of assisted reproductive technology. Sperm analysis, activated caspases, annexin V staining for phosphatidylserine (PS) externalisation and labelling assay for DNA fragmentation were assessed in 122 males of infertile couples. Fifty‐seven couples were allocated to the natural conception group, and 65 couples underwent IVF or ICSI. Semen of IVF/ICSI patients showed a higher proportion of apoptotic spermatozoa in their spermatozoa when compared with a natural conception group (p < .05). Sperm apoptotic biomarkers correlated with age, FSH, and conventional sperm parameters. DNA fragmentation correlated positively with the percentage of semen having externalised PS (r = .78, p = 0) and activated caspases (r = .71, p = 0). Patients without clinical pregnancy had higher frequency of DNA fragmentation, externalised PS and activated caspases compared to patients with clinical pregnancy (p < .001). The best specificity and greater sensitivity were obtained with the test of the DNA fragmentation compared to the other biomarkers. Among the apoptotic biomarkers, only DNA fragmentation was found to predict natural or assisted pregnancy better than conventional sperm parameters.     

Comparison of Tris egg yolk‐based,Triladyl® and Optixell® extender on post‐thaw quality,Kinematics and in vivo fertility of Nili Ravi Buffalo (Bubalus bubalis) bull spermatozoa

Our objectives were to ascertain the comparison of Tris egg yolk‐based, Triladyl ^® and Optixell ^® extender on postthaw quality, CASA parameters and in vivo fertility of Nili Ravi buffalo (Bubalus bubalis) bull spermatozoa. Semen samples (n = 35) from five bulls were diluted in Tris egg yolk‐based, Triladyl ^® , Optixell ^® extender and frozen in 0.50 ml French straws. Postthaw sperm CASA motility (%) was higher (p < 0.05) in Optixell extender as compared to Triladyl and Tris egg yolk‐based extender. Although sperm progressive motility (%), morphology (%), average path velocity (μm/s), straight line velocity (μm/s), curvilinear velocity (μm/s), amplitude of lateral head displacement (μm), beat cross‐frequency (Hz), straightness (%), length of curvilinear path (μm), length of average path (μm), intact plasma and acrosome membrane (%), and DNA integrity (%) were higher (p < 0.05) in spermatozoa cryopreserved in Optixell ^® extender as compared to Tris egg yolk‐based and Triladyl ^® extender. The fertility rates (68.18%, 45.45%, 55.4%) were higher (p < 0.05) in buffaloes inseminated with semen doses frozen in Optixell extender than the Tris egg yolk‐based and Triladyl ^® extender respectively. It is concluded that Optixell ^® extender improves postthaw semen quality and fertility in Nili Ravi buffaloes.     

Assessment of human sperm DNA integrity using two cytochemical tests: Acridine orange test and toluidine blue assay

Primary infertility affects approximately 15% of couples, with male factor infertility accounting for 50% of cases. Semen samples from 41 patients with asthenoteratospermia and 28 men with proven fertility were analysed according to World Health Organization guidelines. Abnormal sperm chromatin structure was assessed by toluidine blue assay (TBA), and DNA denaturation (DD) was detected by the acridine orange test (AOT). The mean (±SEM) rates of DD and abnormal chromatin structure were significantly higher in infertile subjects compared to fertile group respectively p = .003 and p < .001. A significant correlation was established between sperm DD and abnormal chromatin structure (R = .431, p < .001). Sperm DNA damage correlated significantly with abnormal morphology, sperm motility and necrozoospermia. Our study shows that men with increased levels of abnormal sperm chromatin structure have a high incidence of DNA denaturation and altered semen parameters. These findings suggest that male infertility has been linked to sperm DNA damage.     

Selenium and vitamin E supplementation enhances the antioxidant status of spermatozoa and improves semen quality in male dogs with lowered fertility

Studies showed a beneficial effect of supplementation with selenium (Se) and vitamin E on semen quality. The aim of the study was to investigate the effect of Se and vitamin E supplementation on the antioxidant status of spermatozoa and semen quality in dogs with lowered fertility. Ten dogs were supplemented daily with Se (6 μg/kg organic Se yeast) and vitamin E (5 mg/kg) per os for 60 days. Control group consisted of 10 males without the supplementation. Semen was collected on day 0, 30, 60 and 90. Sperm quality parameters were evaluated using CASA and a microscope. Concentrations of Se and vitamin E in blood as well as glutathione peroxidase (GSH‐Px) activity and total antioxidant capacity (TAC) in the spermatozoa were determined. After 60 days of supplementation the concentration of spermatozoa, the majority of motility indicators and the percentage of normal morphology and live spermatozoa increased significantly (p < .05). An increase (p < .05) in concentration of Se and vitamin E in blood and GSH‐Px‐activity and TAC in the spermatozoa was detected. The study results indicate that Se and vitamin E supplementation for 60 days enhances the antioxidant status of spermatozoa and improves the quality of the semen in dogs with lowered fertility.     

Seminal plasma proteins and their relationship with sperm motility and morphology in boars

The identification of biomarkers associated with seminal traits could aid in the selection of higher quality ejaculates and benefit the swine industry. The objective of this study was to identify boar seminal plasma proteins associated with sperm motility and morphology. Twenty ejaculates from fifteen adult boars from a commercial boar stud were used for this work. After routine semen collection and analysis, ejaculates were classified into two groups: high‐quality semen (HQS) and low‐quality semen (LQS), based on sperm motility and morphology. Semen samples were processed for seminal plasma separation and analysis by 2D SDS‐PAGE. Total and progressive sperm motility differed between groups (p < 0.001), as well sperm morphology (p < 0.05). The intensity of spots identified as Major seminal plasma PSP‐I (PSP‐I) and cathepsin B (CTSB) was higher in LQS as compared to HQS samples (p < 0.05). Also, PSP‐I was positively associated with major and sperm cauda defects. Sperm motility was negatively correlated with both PSP‐I and cathepsin B. We conclude that high concentrations of Major seminal plasma PSP‐I and cathepsin B in boar seminal plasma are associated with reduced total and progressive sperm motility and low sperm morphology and might be used as biomarkers for semen quality.     

Association between obesity and alteration of sperm DNA integrity and mitochondrial activity

Study Type – Prognosis (cohort) Level of Evidence 3a What's known on the subject? and What does the study add? The relationship between high levels of BMI and changes in altered standard semen analysis parameters are described in the literature. However, the functional characteristics of the sperm are essential to complete the evaluation of male infertility. Thus, this study provides important information about the functionality of the sperm of men with different levels of BMI.

OBJECTIVE

• ? To assess the effect of obesity on semen analysis, sperm mitochondrial activity and DNA fragmentation.

MATERIALS AND METHODS

• ? A transversal study of 305 male patients, presenting for clinical evaluation, was carried out. The patients were divided into three groups according to body mass index (BMI) as follows: eutrophic (BMI < 25 kg/m², n= 82), overweight (BMI ≥ 25 kg/m² and <30, n= 187) and obese (BMI ≥ 30 kg/m², n= 36).
• ? The variables analysed were semen analysis, rate of sperm DNA fragmentation and sperm mitochondrial activity.
• ? Groups were compared using one‐way analysis of variance followed by a least significant difference post‐hoc test. A P‐value of <0.05 was considered to indicate statistical significance.

RESULTS

• ? No differences were observed in age, ejaculatory abstinence, ejaculate volume, sperm vitality, morphology or round cell and neutrophil count among the groups.
• ? The eutrophic group had a higher percentage of sperm with progressive motility (P= 0.001). Mitochondrial activity was lower in the obese group (P= 0.037) when compared to the eutrophic, and the percentage of sperm with DNA damage was higher in the obese group (P= 0.004) than the other two groups.

CONCLUSION

• ? Increased BMI values are associated with decreased mitochondrial activity and progressive motility and increased DNA fragmentation.

     

Preparation and observation methods can produce misleading artefacts in human sperm ultrastructural morphology

The aim of this study was to evaluate the production of artefacts during preparation and observation of human sperm for ultrastructural morphology and analyse the possible reasons of causing these artefacts. Under the scanning electron microscopy, damaged sperm heads (crack or/and rupture), necks (head‐neck or head‐midpiece separation) and midpiece (disassembled and denuded axoneme ultrastructures, bent midpiece) were analysed to be the consequence of exogenous effects. Thirty infertile men with teratozoospermia revealed more spermatozoa with damage to head, neck and midpiece than did thirty fertile males (p < .01). After the samples from fertile males underwent five repeated observations, most sperm heads and necks in the samples were destroyed when compared with the single observation (p < .01). Destroyed sperm heads were full of cracks and peelings, even sperm tails were broken and fragmented, and separations of the sperm head‐neck or head‐midpiece became common. Spermatozoa from fertile males with centrifugation of 600 g for washing sperm exhibited more damage to the midpiece than those with the 300 g (p < .01). These results demonstrate that preparation and observation methods can damage sperm ultrastructures, leading to producing artefacts of ultrastructural morphology. The artefacts of sperm ultrastructural morphology may be associated with sperm structural fragility, preparation conditions and electron beam damage.     

Red pine (Pinus brutia Ten) bark tree extract preserves sperm quality by reducing oxidative stress and preventing chromatin damage

This study aimed to investigate the effectiveness of using red pine bark tree extract (P; Pinus brutia Ten) as a TRIS extender in an attempt to prevent oxidative stress in bull spermatozoa after freezing. Semen specimens were obtained from Simmental bulls via an artificial vagina and pooled. They were separated into five specimens and diluted with Tris extender consisting of P (200, 100, 50 and 25 µg/ml) and P free (control; C) up to a final concentration of 16 × 10⁶ per straw. All specimens were equilibrated for a period of 4 hr at a temperature of 4°C, following which they were filled in 0.25-ml French straws and frozen. Addition of P resulted in favourable tail length in comparison with C (p < .05). The lowest malondialdehyde levels and the highest glutathione levels were detected in all P groups (p < .05). Supplementation with P did not show advanced results in terms of total, progressive sperm motility and total abnormality in comparison with C (p > .05). In conclusion, it has been shown that although P added to a Tris extender does not have a positive effect on sperm motility, it prevents chromatin damage by reducing oxidative stress, in addition to reducing head abnormalities when used at the amount of 50 μg/ml.     

The impact of body mass index on semen parameters in infertile men

This hospital‐based, prospective study was conducted to evaluate the relationship between body mass index (BMI) and various semen parameters in infertile men. A total of 439 men presented for infertility evaluation were assessed by basic infertility evaluation measures including semen analysis and BMI calculation. The main outcome measure was the relationship between BMI groups [BMI: 18.5–24.9 kg/m² (normal weight), 25–29.9 kg/m² (overweight) and ≥30 kg/m² (obese)] and different semen parameters [volume, concentration, motility and morphology]. The mean BMI was 29.67 ± 5.89. Most of patients (82.91%) were overweight or obese. The 3 BMI groups were comparable in semen parameters (P > 0.05). BMI had a negative correlation with various semen parameters. However, this correlation was significant only with sperm concentration (P = 0.035). We concluded that sperm concentration was the only semen parameter which showed significant reduction with higher BMI in infertile men.     

The presence of seminal plasma,especially derived from stallion semen,helps preserve chilled Asian elephant (Elephas maximus) sperm motility

The effects of seminal plasma (SP), derived from autologous, homologous and heterologous species (stallion, boar and dog) on chilled Asian elephant sperm quality, were determined. Semen was collected from eight males and samples with ≥30% motile spermatozoa were used in the study. Semen was diluted with Tris–glucose–egg yolk extender, supplemented with different SP types and preserved at 4°C for 48 hr. Experiment 1 (n = 31), showed that the presence of SP (autologous) helped to preserve sperm quality in terms of sperm motility and acrosome integrity (p < .05). Homologous SP did not result in better sperm quality than autologous SP. Heterologous SP from stallion provided higher sperm motility and velocities compared to autologous SP (p < .05). Experiment 2 (n = 14) determined the effect of different SP from four stallions. All stallion SP gave higher (p < .05) results for motile spermatozoa and sperm velocities than autologous SP. In conclusion, the presence of SP helps preserve Asian elephant sperm quality and stallion SP supports the motility of Asian elephant spermatozoa during cold storage.     

Sperm mitochondrial DNA deletion in Iranian infertiles with asthenozoospermia

Asthenozoospermia is an important cause of male infertility. The mutations in sperm mitochondrial DNA (mtDNA) result in either functionless or malfunctioning some proteins, subsequently affecting sperm motility leading to asthenozoospermia. The purpose of this study was to investigate sperm mtDNA 4,977‐bp deletion in infertile men with low sperm motility/immotile spermatozoa compared to healthy subjects with high sperm motility. Semen samples of 256 asthenozoospermic infertiles and 200 controls from northern Iran were collected. After extraction of spermatozoa total DNA, Gap‐polymerase chain reaction (Gap‐PCR) was performed. The deletion was observed in 85.93% of patients with asthenozoospermia compared with 14% in controls [OR = 37.5397, 95% confidence interval = 12.937–108.9276, p < .0001]. It is concluded that there is a strong association between sperm mtDNA 4,977‐bp deletion and asthenozoospermia‐induced infertility in the population examined. Large‐scale mtDNA deletions in spermatozoa may induce bioenergetic disorders. Nevertheless, to validate our results broader research may be needed.     

Effect of ghrelin on total antioxidant capacity,lipid peroxidation,sperm parameters and fertility in mice against oxidative damage caused by cyclophosphamide

Cyclophosphamide is a drug used for chemotherapy and as an immune‐suppressive in the organ transplantation. Despite its many clinical implications in the treatment of cancers, this drug has toxic effects on the reproductive system. This study aimed to evaluate the effect of ghrelin against the damages caused by cyclophosphamide. In this experimental study, 40 male mice were randomly divided into four groups: (i) control; (ii) cyclophosphamide; (iii) cyclophosphamide + ghrelin; and (iv) ghrelin. Cyclophosphamide (100 mg/kg body weight), once a week, and ghrelin (80 μg/kg body weight), daily, were administered intraperitoneally for 5 weeks. After 5 weeks, the epididymides were removed and the lipid peroxidation, total antioxidant capacity and sperm parameters were examined. The fertility rate was evaluated by performance in vitro fertilisation. In the mice exposed to cyclophosphamide, the number of spermatozoa and viability, as well as total antioxidant capacity, decreased significantly (p < .05). The increase in the abnormal sperm and MDA levels was observed (p < .05). In addition, the fertility rate decreased in this group, while the use of ghrelin significantly improved the above disorders in the treatment group (p < .05). The findings of this study showed that ghrelin attenuates negative effects caused by cyclophosphamide in the sperm parameters and enhances the fertility.     

The effect of cigarette smoking on human seminal parameters,sperm chromatin structure and condensation

Considerable debate still exists regarding the effects of cigarette smoking on male fertility. This work aimed to explore effects of cigarette smoking on semen parameters and DNA fragmentation on 95 infertile patients who were divided into infertile male nonsmokers (45) and infertile male smokers (50). Smokers were subdivided according to a number of cigarettes smoked per day into mild (≤10), moderate (11‐20) and heavy smokers (≥21). Semen analysis, sperm chromatin condensation integrity with aniline blue staining and sperm viability were compared between the study groups. A significant decrease has been shown in sperm count (p = .006), progressive motility (p = <.001), percentage of normal forms (p = <.001) and viability (p = .002) between infertile nonsmoker and infertile smokers. The percentage of abnormal sperm chromatin condensation was significantly higher in smokers compared to nonsmokers (p = <.001). A linear correlation was detected between the extent of cigarette smoking and the degree of worsening in progressive motility (p = .001), total motility (p < .001), viability (p < .001) and normal morphology (p < .001). These results indicate that cigarette smoking has detrimental effects on semen parameters. It negatively affected all conventional semen parameters in addition to sperm chromatin condensation and sperm viability. These abnormalities were also proportional to the number of cigarettes smoked per day and to the duration of smoking.     

Association of lifestyle factors with semen quality: A pilot study conducted in men from the Portuguese Trás-os-Montes and Alto Douro region followed in fertility support consultations

A cross-sectional pilot study was conducted in men followed in fertility consultations, from the portuguese Trás-os-Montes and Alto Douro region, in order to associate several lifestyle factors with the spermatic parameters. Of a total of 522 men, 373 were compared based on the occupational exposure to harmful factors, smoking habits and practice of physical exercise per week, and the other 149 men according to their body mass index (normal weight vs. overweight vs. obesity). In the absence of harmful occupational factors, physical exercise seems to be associated with sperm quality improvement, whether individuals smoke or not. When exposed to harmful environments, non-smokers that practice physical exercise more than two times per week tended to present the best vitality, normal morphology and sperm concentration (p > .05). However, if they smoke, physical exercise seems not enough to enhance the spermatic parameters. The BMI correlated negatively with the spermatic quality, especially with sperm concentration (p < .05). Concerning men that did not present lifestyle risks associated, the motility, midpiece and tail abnormalities, and teratozoospermia index were significantly worse on obese individuals comparing to overweight men (p < .05). Thus, patients should also be recommended to control their weight and to have a BMI under 30 kg/m².     

Impact of body mass index values on sperm quantity and quality

Body mass index (BMI) has been demonstrated to affect female fertility; however, little information is available on the impact of BMI on male fertility or semen parameters. Therefore, the study objective was to determine the relationship between BMI and semen parameters, including sperm chromatin integrity. We analyzed data on semen samples from 520 men who were grouped based upon calculated BMI values (normal, 20-24 kg/m(2); overweight, 25-30 kg/m(2); obese, >30 kg/m(2)). The data collected included patient height and weight, semen volume, sperm concentration, percent sperm motility, percent sperm morphology (normal forms), and sperm chromatin integrity (DNA fragmentation index [DFI]). Data were analyzed by regression analysis and analysis of variance (ANOVA) with Tukey's test for multiple pairwise comparisons. The overall BMI mean (+/-SEM) was 27.5 (+/-0.49) kg/m(2). Linear regression revealed a significant (P < .05) and negative relationship between BMI and the total number of normal-motile sperm cells. ANOVA revealed a significant difference (P < .05) in the total number of normal-motile sperm cells among the different BMI groups. The number of normal-motile sperm cells per BMI group was as follows: normal, 18.6 x 10(6); overweight, 3.6 x 10(6); and obese, (0.7) x 10(6). All multiple pairwise comparisons were found to be significantly (P < .05) different. The overall DFI mean (+/-SEM) was 24.7 (+/-2.57). Linear regression revealed a significant (P < .05) and positive relation between BMI and DFI. Men presenting with a BMI greater than 25 kg/m(2) have fewer chromatin-intact normal-motile sperm cells per ejaculate. Therefore, to ensure maximum fertility potential, patients may be advised to reduce body weight.     

Supplementing post-wash asthenozoospermic human spermatozoa with coenzyme Q10 for 1 hr in vitro improves sperm motility,but not oxidative stress

We investigated the effect of supplementing post-wash asthenozoospermic spermatozoa with coenzyme Q10 (CoQ10) in vitro, which may reduce oxidative stress and improve sperm motility. Semen samples were collected from 39 men with asthenozoospermia, and their spermatozoa were isolated by two-layer Percoll density-gradient centrifugation. Kinetic parameters of the isolated spermatozoa (baseline before intervention) were determined immediately by computer-aided semen analysis. Total anti-oxidant capacity and protein carbonyl levels, as markers of oxidative stress, were also measured in the baseline spermatozoa. The baseline spermatozoa suspension was divided equally into two portions, one for CoQ10 supplementation (50 µg/ml for 1 hr) and the other as an un-supplemented vehicle control. The total motility of the CoQ10-supplemented spermatozoa was significantly higher than in the control (p = .009) and progressive motility tended to be higher (p = .053). Immotile sperm concentration in the CoQ10-supplemented spermatozoa was significantly lower than in both the baseline (p = .026) and control (p = .009). Total anti-oxidant capacity and protein carbonyl levels between the baseline, CoQ10-supplemented and control spermatozoa were not significantly different. Our data suggest that CoQ10 treatment reactivated sperm motility. We propose short-term supplementation of post-wash asthenozoospermic spermatozoa with CoQ10 before intrauterine insemination.     

Quality of human spermatozoa: relationship between high‐magnification sperm morphology and DNA integrity

The aim of this work is to establish the relationship between the morphology of Intracytoplasmic Morphologically Selected Sperm Injection (IMSI)‐selected spermatozoa and their DNA integrity. The 45 ejaculates were randomly distributed into three treatment groups: normozoospermic, oligoasthenozoospermic and oligoasthenotheratozoospermic samples. The evaluation of DNA integrity was performed using the sperm chromatin dispersion test. It was established that DNA integrity of spermatozoa is strongly dependent on ejaculate quality (P < 0.05). The count of spermatozoa with nonfragmented DNA in normozoospermic samples was high and independent from IMSI‐morphological classes (Class 1 versus Class 3, respectively) (P > 0.1). With decreased ejaculate quality, the percentage of spermatozoa with nonfragmented DNA decreased significantly (P < 0.05) independent from morphological class. Nevertheless, the rate of IMSI‐selected spermatozoa with fragmented DNA within of Class 1 in normozoospermic (Group 1), in oligoasthenozoospermic (Group 2) and in oligoasthenotheratozoospermic (Group 3) samples was 21.1%, 31.8% and 54.1%, respectively. In conclusion, there is a direct relationship between morphological parameters of spermatozoa and their DNA integrity. However, the IMSI technique alone is not enough for the selection of spermatozoa with intact nuclei.