Association between body mass index and sperm quality and sperm DNA integrity. A large population study

This study aimed to analyse whether the functional quality of spermatozoa is associated with body mass index (BMI). Semen samples were obtained from 1824 men undergoing fertility evaluation/treatment. Semen analysis was performed using World Health Organization (WHO) criteria, and morphology was evaluated with the motile sperm organelle morphology examination (MSOME). The percentages of sperm DNA fragmentation (using TdT (terminal deoxynucleotidyl transferase)‐mediated dUTP nick‐end labelling (TUNEL) assays), sperm chromatin packaging/underprotamination (using chromomycin A3/CMA₃), mitochondrial damage (using MitoTracker Green) and apoptosis (using annexin V) were also assessed. At least 200 spermatozoa were examined in each evaluation. The following BMI values were used as cut‐off points: ≤24.9 kg/m², 25–29.9 kg/m² (overweight) and ≥30 kg/m² (obese). High BMI negatively affects sperm concentration, vitality, motility and morphology (p < .05). Conversely, high BMI does not seem to be associated with impaired sperm DNA integrity, as assessed by DNA fragmentation, sperm protamination and sperm apoptosis (p > .05). However, increased BMI is associated with increased mitochondrial damage in spermatozoa (p < .05). In conclusion, given the adverse consequences of obesity and the possible effect of male BMI on assisted reproduction technology (ART) outcomes, the benefits of weight reduction should be discussed when counselling couples interested in fertility treatment.     

Effect of metformin therapy and dietary supplements on semen parameters in hyperinsulinaemic males

Previous reports indicated that hyperinsulinaemic men may exhibit a higher percentage of poorly compacted DNA in their spermatozoa and less success in an IVF programme (Andrologia, 45, 2003, 18; Andrologia, 2014, doi: 10.1111/and.12227 ). The aim of this study was to investigate the effect of metformin (Glucophage^®) and antioxidant treatment (StaminoGro^®) on the semen parameters of hyperinsulinaemic men. Nineteen hyperinsulinaemic male patients were treated for 3 months with metformin alone (Group A), and fifteen patients used metformin in combination with the nutritional supplement (Group B). Combined data of the two groups (pre‐ and post‐treatment) differ significantly regarding sperm morphology (P = 0.0003) and CMA₃ (P < 0.0001) values. The improvement in sperm morphology after treatment was similar for the two respective groups (P < 0.05). The morphological normal sperm forms increased from the mean percentage of 3.9 to 5.5% and from 4.2 to 5.5% for Group A and B respectively. Where a combination of metformin and the supplement were used (Group B), the combination treatment proved to be superior in obtaining enhanced chromatin packaging quality although not statistically significant (P = 0.5929) when compared with the metformin (Group A) group. The chromatin packaging quality in Group B improved with 10% while the improvement in Group A was approximately 8.3%. Therefore, infertile hyperinsulinaemic men can benefit from metformin treatment and should be advised on the use of nutritional supplements with antioxidant properties.     

Accurate sperm morphology assessment predicts sperm function

Sperm morphology has been associated with in vitro as well as in vivo fertilisation. The study aimed to evaluate the possible relation between the percentage of spermatozoa with normal morphology and the following sperm functional assays: (i) zona-induced acrosome reaction (ZIAR); (ii) DNA integrity; (iii) chromatin condensation; (iv) sperm apoptosis; and (v) fertilisation rates. Regression analysis was employed to calculate the association between morphology and different functional tests. Normal sperm morphology correlated significantly with the percentages of live acrosome-reacted spermatozoa in the ZIAR (r = 0.518; P < 0.0001; n = 92), DNA integrity (r = -0.515; P = 0.0018; n = 34), CMA(3) -positive spermatozoa (r = -0.745; P < 0.0001; n = 92), sperm apoptosis (r = -0.395; P = 0.0206; n = 34) and necrosis (r = -0.545; P = 0.0009; n = 34). Negative correlations existed between for the acrosome reaction, and DNA integrity, while negative associations were recorded with the percentages of CMA(3) -positive spermatozoa, apoptotic and necrotic spermatozoa. Sperm morphology is related to sperm dysfunction such as poor chromatin condensation, acrosome reaction and DNA integrity. Negative and significant correlations existed between normal sperm morphology and chromatin condensation, the percentage of spermatozoa with abnormal DNA and spermatozoa with apoptotic activity. The authors do not regard sperm morphology as the only test for the diagnosis of male fertility, but sperm morphology can serve as a valuable indicator of underlying dysfunction.     

Influence of extended incubation time on Human sperm chromatin condensation,sperm DNA strand breaks and their effect on fertilisation rate

The purpose of this study was to determine influence of extended incubation time on sperm chromatin condensation and DNA strand breaks and their effect on fertilisation rate. Forty couples undergoing ICSI therapy were included. Semen was prepared by PureSperm gradient centrifugation and divided into two parts. The first part (G1) was used immediately for ICSI, whereas the second part (G2) was kept in the incubator at 37°C, 5% and 90% Humidity for 5 hr, and thereafter, the capacitated spermatozoa were used for ICSI. The TUNEL test and chromomycin CMA3 were used to evaluate the DNA strand breaks and chromatin condensation respectively. The percentage of condensed chromatin was 73.92 ± 12.70 in the group 1 and 81.13 ± 10.31% in group 2 (p = .001). However, the double‐strand breaks were 11.15 ± 8.67% in G.1 and 16.30 ± 11.12% in G.2. (p = .001). Fertilisation rate in the (Group 1) was 62.45% and 69.17% in (Group 2). There was a positive correlation between condensed chromatin and fertilisation rate (r = 0.846, p = .001) and a negative correlation with DNA double‐strand breaks (r = ?0.802; p = .001). In conclusion, the prolonged sperm incubation (5 hr) leads to a higher chromatin condensation and to a significantly increased number of DNA strands double breaks with no influence on fertilisation rates.     

Sperm chromatin quality and DNA integrity in partial versus total globozoospermia

Globozoospermia is a severe form of teratozoospermia with low incidence in infertile patients, considered as one of the important causes of male infertility. The objective was to investigate the chromatin/DNA integrity as well as apoptosis in ejaculated spermatozoa of cases with partial or total globozoospermia. Fifty‐seven semen samples were divided into three groups of partial globozoospermia (n = 17), total globozoospermia (n = 10) and normozoospermia (control; n = 30). Sperm chromatin condensation, DNA integrity and apoptosis were assessed using cytochemical assays. The results showed significant differences in sperm parameters of count and motility between two case groups versus controls. The percentages of spermatozoa with abnormal chromatin packaging and protamine deficiency were significantly higher in total and partial globozoospermic men compared to normozoospermic samples. Also, the rates of TUNEL‐positive spermatozoa were significantly increased in both globozoospermic cases with respect to the control (18.3 ± 10.1 and 12.3 ± 9.2 versus 5.9 ± 3 respectively). However, no significant differences were noticed between two subgroups of patients with regard to sperm DNA denaturation, DNA fragmentation and apoptosis. Abnormal chromatin packaging, DNA damage and apoptosis were significantly higher in cases than controls. The sperm chromatin/DNA anomalies may be considered as one of the main aetiology of ART failure in globozoospermic patients.     

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.     

Effect of Cissampelos capensis rhizome extract on human spermatozoa in vitro

Cissampelos capensis is commonly known by the Afrikaans name ‘dawidjies’ or ‘dawidjieswortel’. C. capensis is the most important and best‐known medicinal plant of the family Menispermaceae used by the Khoisan and other rural people in the western regions of South Africa. Among numerous other ailments, it is traditionally taken to treat male fertility problems. Yet, no studies have investigated the effects of this plant or its extracts on human spermatozoa. The aim of study was to investigate the effects of C. capensis extracts on sperm function. A total of 77 semen samples were collected. Spermatozoa were washed with HTF‐BSA medium and incubated with different concentrations of C. capensis (0, 0.05, 0.5, 5, 50, 200 μg ml^?1) for 1 h at 37 °C. Sperm motility, vitality, acrosome reaction, reactive oxygen species (ROS), capacitation, Annexin V binding, DNA fragmentation and mitochondrial membrane potential (Δψ_m) were determined. While viability, Annexin V positivity and Δψ_m were not affected, the percentages of ROS‐positive, TUNEL‐positive, capacitated and hyperactivated spermatozoa increased significantly and dose‐dependently. It is concluded that the alkaloids present in the extract of C. capansis rhizomes triggered sperm intrinsic superoxide production leading to sperm capacitation and DNA fragmentation.     

Relationship between chromatin condensation, DNA integrity and quality of ejaculated spermatozoa from infertile men

Normal chromatin condensation is important for sperm fertilising ability. However, routine semen analysis does not identify defects in sperm chromatin structure. This study aimed to investigate the condensation of chromatin and DNA integrity in spermatozoa of infertile men and deduce the relationship with sperm quality, as measured by conventional semen parameters. Semen analysis was carried out to assess sperm quality according to World Health Organization criteria. The remaining aliquot of each sample was processed for transmission electron microscopy, chromomycin A3 (CMA3) and terminal deoxynucleotidyl transferase dUTP nick end labelling (TUNEL) assays. The ultrastructural analysis of spermatozoa from infertile men showed heterogeneity in sperm nuclear morphology. Some spermatozoa displayed a round nucleus with incomplete chromatin condensation. Immunoreactivity with antitransitional protein and antiprotamine antibodies indicated nuclear maturation defects in the spermatozoa of infertile men. Spearman's correlation analysis indicated a positive correlation between the percentages of CMA3- and TUNEL-positive spermatozoa. In addition, these two parameters were negatively correlated with sperm concentration, motility and normal morphology. This study demonstrated that men with morphologically normal spermatozoa of <30% have greater degree of protamine deficiency and DNA damage than men with morphologically normal spermatozoa of >30%. Evaluation of chromatin integrity appears to be a useful tool for assessing male fertility.     

Nuclear sperm quality in total polymorphic teratozoospermia and its impact on intracytoplasmic sperm injection outcome

Various nuclear sperm alterations are reported in patients with syndromic teratozoospermia; however, this has not been clearly identified yet in total polymorphic teratozoospermia. The aim of this study was to analyse sperm aneuploidy, DNA integrity and chromatin packaging in 45 infertile patients with total polymorphic teratozoospermia, and to compare obtained results with those collected from 25 fertile men. For 14 patients, the impact of nuclear sperm abnormalities on intracytoplasmic sperm injection (ICSI) outcomes was analysed. Sperm chromatin condensation was evaluated using aniline blue staining, DNA fragmentation by TUNEL assay and chromosome abnormalities by FISH. The mean DNA fragmentation index was significantly higher in patients compared to controls, weakly and positively correlated to acrosome defects (r = 0.3; p = 0.04) and positively and moderately correlated to microcephalic heads (r = 0.5; p = 0.027). The aniline blue‐reacted spermatozoa rate was also high in comparison with controls, moderately and negatively correlated to progressive motility (r = ?0.6; p = 0.014). Total aneuploidy rate was considerably higher in our patients. A positive and moderate correlation was found between disomy Y rate and acrosome abnormalities (r = 0.5; p = 0.048). These patients had an impaired sperm nuclear quality, which will affect the results in ICSI. Therefore, analysis of sperm chromatin condensation, DNA integrity and aneuploidy in such cases is very useful before ART.     

How accurate is sperm morphology as an indicator of sperm function?

Sperm morphology has been consistently correlated with fertilisation success or failure. The clinical relevance of the percentage normal spermatozoa has been a widely discussed topic amongst infertility specialists and scientists. This study aimed to evaluate the role of sperm morphology as an indicator of additional sperm functions among 114 andrology referrals. The sperm functions that were investigated included chromatin packaging quality (CMA3 test (n = 109), zona‐induced acrosome reaction (ZIAR test; n = 36), hemizona assay (HZI; n = 36) and progressive motility (n = 47). Chromatin packaging quality had a negative and significant (P = 0.0001, r = ?0.74) correlation with the percentage normal spermatozoa, while progressive motility had a significant and positive correlation (P = 0.0001, 0.59). Accurate sperm morphology scoring as described by the WHO 2010 manual can therefore be used as an indicator of specific sperm functions.     

Semiquantitative promoter methylation of MLH1 and MSH2 genes and their impact on sperm DNA fragmentation and chromatin condensation in infertile men

To investigate the semiquantitative methylation alterations of MLH1 and MSH2 and the possible association among methylation of MLH1 and MSH2, sperm DNA fragmentation and sperm chromatin condensation in idiopathic oligoasthenoteratozoospermic men. Seventy-five idiopathic infertile men and 52 fertile and/or normozoospermic men were included in the study. SDF was analysed using the TUNEL assay in semen samples of 100 men. Promoter methylation of MLH1 and MSH2 genes was assessed by semiquantitative methylight analysis in semen samples of 39 and 40 men respectively. Sperm chromatin condensation was evaluated using aniline blue staining in 114 men. MLH1 promoter methylation was positively correlated with the percentage of aniline blue positive spermatozoa (r = 0.401, p = 0.0188). On the other hand, MSH2 promoter methylation was negatively correlated with sperm concentration and total sperm count (r = −0.421, p = 0.0068 and r = 0.4408, p = 0.009 respectively). The percentage of aniline blue positive spermatozoa in the control group was significantly lower than in the OAT group (p < 0.0001) and negatively correlated with total sperm count (r = −0.683, p < 0.0001), progressive sperm motility (r = −0.628, p < 0.0001), total motility (r = −0.639, p < 0.0001) and normal morphology (r = −0.668, p < 0.0001). Promoter methylation profile of MLH1 and MSH2 genes may play role on sperm DNA packaging and conventional semen parameters respectively.     

Effects of Chlamydia trachomatis infection on sperm chromatin condensation and DNA integrity

The present study was performed to investigate the relation of Chlamydia trachomatis infection to sperm chromatin/DNA integrity in a population of infertile men (male partner of infertile couples) from Iran. Blood, semen and first‐void urine samples were obtained from 250 infertile men. Data were analysed with regard to the results of (i) serological analysis for specific antibodies to C. trachomatis in serum; (ii) the presence of C. trachomatis and DNA in first‐void urine; and (iii) in the semen sample of the male partner, in addition to sperm analysis, four different tests (aniline blue, chromomycin A3, acridine orange and TUNEL) were used to detect sperm chromatin and DNA abnormalities. The main conclusions of the results were: (i) no evidence of C. trachomatis infection in semen samples was found; (ii) sperm DNA fragmentation and chromatin studies were not correlated with C. trachomatis diagnosis; (iii) the percentage of DNA fragmentation is positively correlated with the percentage of immotile sperm but negatively with semen volume, normal morphology; and (iv) in sperm chromatin evaluations, only the percentage of chromatin protamination was related to male age.     

Porcine sperm vitrification II: Spheres method

Owing to current problems in boar sperm cryopreservation, this study proposes to evaluate vitrification in spheres as an alternative cryopreservation procedure, comparing the use or not of permeable cryoprotectants and two warming methods. Extended (n = 3; r = 4) and raw (n = 5; r = 2) porcine spermatozoa were diluted in media, in the absence or presence of either 4% dimethylformamide or 4% glycerol, to a final concentration of 5 × 10⁶ spermatozoa/ml and vitrified using the spheres method. Two warming procedures were evaluated: a rapid method (30 s at 37°C) and an ultrarapid method (7 s at 75°C, followed by 30 s at 37°C). Percentages of total motility (phase contrast), membrane function (hypo‐osmotic swelling test), acrosome integrity (phase contrast), sperm viability (6‐carboxyfluorescein diacetate and propidium iodide stain), chromatin condensation (toluidine blue stain) and chromatin susceptibility to acid denaturation (acridine orange stain) were evaluated in the samples before and after vitrification. Results, analysed using Friedman's test, suggest that rapid warming of raw porcine spermatozoa vitrified without permeable cryoprotectants may preserve DNA condensation and integrity better than the other processing methods studied in this work. Hence, porcine sperm vitrification using spheres could be used to produce embryos with ICSI to further validate this method.     

Porcine sperm vitrification I: cryoloops method

The aims of this study were to evaluate porcine sperm vitrification in cryoloops, with and without two different cryoprotectants and assess two warming procedures. Extended (n = 3; r = 4) and raw (n = 5; r = 2) semen was diluted in media without and with cryoprotectants (4% dimethylformamide and 4% glycerol) to a final concentration of 20 × 10⁶ spermatozoa ml^?1 and vitrified using the cryoloops method. Two warming procedures were evaluated: rapid method (30 s at 37°C) and an ultra‐rapid method (7 s at 75°C, followed by 30 s at 37°C). Total motility (phase contrast), sperm viability (6‐carboxifluorescein diacetate and propidium iodide stain), membrane function (hypo‐osmotic swelling test), acrosome integrity (phase contrast), chromatin condensation (toluidine blue stain) and chromatin susceptibility to acid denaturation (acridine orange stain) were evaluated before and after vitrification and analysed using Friedman's test. In all media, the only seminal parameters that were maintained after vitrification were chromatin condensation and integrity. Vitrification of porcine spermatozoon using cryoloops, both in the presence or absence of cryoprotectants and independent of the warming procedure used, permits conservation of sperm chromatin condensation and integrity. It would be interesting to further verify this by producing porcine embryos using vitrified spermatozoon with intracytoplasmic sperm injection.     

Investigation of the association between the outcomes of sperm chromatin condensation and decondensation tests,and assisted reproduction techniques

The main purpose of this prospective study is to examine possible influences of abnormalities of sperm nuclear condensation and chromatin decondensation with sodium dodecyl sulphate (SDS)‐EDTA on outcomes of intrauterine insemination (IUI) or intracytoplasmic sperm injection (ICSI) cycles. Semen samples from 122 IUI and 236 ICSI cycles were evaluated. Before semen preparation for IUI or ICSI, basic semen analysis was performed and a small portion from each sample was spared for fixation. The condensation of sperm nuclear chromatin was evaluated with acidic aniline blue, followed by sperm chromatin decondensation by SDS‐EDTA and evaluation under light microscope. Ongoing pregnancy rate was 24% and 26.2% in the IUI and ICSI groups respectively. The chromatin condensation rate was significantly higher in the ongoing pregnancy‐positive group compared to the negative group, both in IUI (P = 0.042) and ICSI groups (P = 0.027), and it was positively correlated with ongoing pregnancy rate in both IUI and ICSI groups (P = 0.015, r = 0.214 and P = 0.014, r = 0.312 respectively). Chromatin decondensation rates were not significantly different in neither of the groups. These results indicate that IUI and ICSI outcome is influenced by the rate of spermatozoa with abnormal chromatin condensation. Sperm chromatin condensation with aniline blue is useful for selecting assisted reproduction techniques (ART) patients.     

Evaluation of the cryoprotective effect of seminal plasma on llama (Lama glama) spermatozoa

In South American camelids, sperm survival is low after thawing and poor results are obtained when artificial insemination is performed with cryopreserved semen. The aim of this study was to evaluate the effect of different percentages (10% and 50%) of seminal plasma added prior to the process of cryopreservation and also to evaluate the absence of seminal plasma on llama sperm survival after freezing and thawing. A total of 15 ejaculates from five adult llama males (n = 5; r = 3) were evaluated. A significant decrease in sperm motility, viability, membrane function and intact acrosomes was observed in thawed samples (0%, 10% and 50%) when compared to raw semen. Neither morphology nor chromatin condensation was altered in all thawed samples (p > 0.05), but a significant increase (p < 0.05) in the percentage of spermatozoa with fragmented DNA was observed after thawing all samples compared to raw semen. Higher percentages of total and progressive sperm motility were observed when 0% and 10% of seminal plasma were used compared to 50%. However, no statistical differences were established for sperm viability, membrane function, morphology, acrosome status and DNA quality between thawed treatments. To conclude, neither of the percentages of seminal plasma used showed superiority nor cryoprotective effect on llama sperm survival.     

Insight into curcumin nanomicelle‐induced derangements in male reproduction potential: An experimental study

This study was conducted to investigate the possible effects of nanomicelle curcumin (NMC) on spermatogenesis, sperm parameters and in vitro fertilisation potential. For this purpose, 24 mature male Wistar rats were divided into control and test groups. The animals in test groups received 7.5, 15 and 30 mg kg b.w^?1 of NMC (NO = 6 rats in each group). Following 48 days, the DNA integrity of testicular tissues, tubular differentiation (TDI) and spermiogenesis (SPI) indices, sperm parameters and DNA integrity were analysed. Finally, the in vitro fertilisation potential was investigated via evaluating pre‐implantation embryo generation. The NMC diminished the TDI and SPI ratios. The animals in NMC‐received groups exhibited a remarkable (p < .05) reduction in percentage of alive and motile spermatozoa. Moreover, the NMC enhanced the percentage of spermatozoa with decondensed chromatin and elevated the sperm DNA damage ratio. The testicles of NMC‐received groups exhibited severe DNA fragmentation. The percentages of zygote, 2‐cell, blastocysts and hatched embryos generation were decreased in NMC‐received groups compared to control animals. In conclusion, the NMC adversely affects the spermatogenesis and spermiogenesis processes, which in turn results in reducing the sperm quality. Ultimately, decreased sperm quality results in lower pre‐implantation embryo development.     

A human morphologically normal spermatozoon may have noncondensed chromatin

According to numerous assisted reproductive medicine practitioners, semen with normal characteristics might not require further investigation. However, on the scale of the individual spermatozoon, it is well known that normal morphology does not guarantee optimal nuclear quality. Here, for 20 patients with normal sperm characteristics and a high proportion of spermatozoa with noncondensed chromatin, we subsequently assessed chromatin condensation status (aniline blue staining) and morphology (Papanicolaou staining) of the same 3749 spermatozoa. Although the overall proportion of morphologically normal spermatozoa was not correlated with the overall proportion of spermatozoa with noncondensed chromatin, an individual spermatozoon's morphology appeared to be closely related to its chromatin condensation status. Morphologically normal spermatozoa with noncondensed chromatin were seen in all patients; the proportion averaged 23.3% [min 10.9%–max 44.4%]. Morphologically abnormal spermatozoa were more likely to have noncondensed chromatin than morphologically normal ones (P < 0.0001). Small‐, large‐ or multiple‐headed spermatozoa presented the highest degree of noncondensation (>80% for each type), and more than half the vacuolated spermatozoa also presented noncondensed chromatin. However, a morphologically normal spermatozoon may also have a noncondensed chromatin.     

Gradient sperm selection for reproductive techniques in cattle: Is Isolate a suitable replacement for Percoll?

In assisted reproductive techniques, it is essential to perform a sperm selection to obtain spermatozoa with high motility and membrane integrity for in vitro fertilisation (IVF) and high‐DNA integrity for intracytoplasmic sperm injection (ICSI). In this study, we evaluated whether Isolate ^® was a suitable substitute for Percoll ^® for assisted reproductive techniques. Commercial cryopreserved bovine semen was used after selection in both gradients, and plasma and acrosome membrane integrity, reactive oxygen species (ROS) levels, DNA integrity and mitochondrial membrane potential (ΔΨm) were assessed by flow cytometry. Motility parameters were also evaluated by CASA system. A similar percentage of spermatozoa with intact plasma membrane, acrosome integrity and high ΔΨm was observed in both sperm selection methods, but only Percoll ^® showed higher percentage of spermatozoa with intact plasma and acrosome membrane compared to the post‐thawing group. No differences were observed in the motility, ROS, DNA fragmentation and on the in vitro embryo production in all experimental groups. In conclusion, the selection of bovine spermatozoa with Isolate ^® generates spermatozoa with similar quality parameters and embryonic development compared to Percoll ^® providing a suitable alternative sperm selection method for assisted reproductive techniques in this species.     

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.