Male Semen Research Articles

Acrosome reaction in the epididymal sperm of Chinchilla lanigera. Effect of progesterone, A23187 and stimulation of a GABAA-like receptor.

Little is known about the reproductive biology of Chinchilla lanigera in captivity. Currently there are no parameters to evaluate the quality of the semen of males that are sold as breeding stock, so they are selected according to their phenotypic characteristics, which cannot guarantee their reproductive efficiency. We worked with sexually mature males; the sperm were collected from the cauda epididymis by puncture. Capacitated sperm were incubated at 37 °C with different concentrations of progesterone. The results showed a biphasic behavior, where the increase in the percentage of the acrosome reaction (AR) was significant between 2.5-5 μM, and a maximum response with a dose of 20 μM. Also the suspension of sperm incubated with different concentrations of ionophore A23187 inducing response is obtained with a concentration of 10 μM. Stimulation of the Gamma-aminobutyric acid (GABA)A -like receptor by treating the sperm with different concentrations of muscimol, a specific receptor agonist, also induce acrosome reaction. The dose-response curve showed a biphasic effect with a maximum response at a concentration of 2.5 μM. The pretreatment of sperm suspension with a specific receptor antagonist, picrotoxin, a decrease was observed in the percentage of reacted perm. These studies represent a first step towards the establishment of standard parameters to determine the functionality and fertilizing capacity of Chinchilla sperm. In addition, our results indicate that the Chinchilla spermatozoa can undergo the AR when treated with A23187 or progesterone at high percentages. It also shows a clear involvement of GABAA -like receptors in acrosome exocytosis in sperm obtained by epididymal cauda.

Estimation of the seminal fluid of subfertile patients of different age groups.

Background: Among different lifestyle factors, aging process can adversely affect male semen parameters and hence male fertility in this study, semen parameters and productive hormonal profiles of subfertile young men were compared with subfertile middle and old age men.

Semen Analysis From A Point Of View Of Gynecologist And Recent Developments

SUMMARY Infertility is defined as the time of one year of unprotected intercourse without conception and affects approximately 15% of the couples. Data available over the years reveal that pathology is found among 55% of cases in women, 35% of cases in men and the remaining 10% of cases are defined as unexplained infertility. Male infertility is commonly due to deficiencies in the semen and semen quality is used as a surrogate measure of male fecundity. A semen analysis evaluates certain characteristics of a male's semen and the sperm contained in the semen. It should be the first laboratory investigation for men while evaluating a couple's infertility. Here, we tried to review the semen analysis as a very important laboratory investigation in evaluating the infertile couples with all points in the light of last published World Health Organization (WHO) criteria.

Vitamin E Mitigates Chronic Chlorpyrifos-Induced Oxidative Changes in Pituitary Glands and Testes in Wistar Rats

Problem statement: The sperm counts of men have declined by about 50% in the last few decades. The contribution of environmental contaminants to this decline cannot be overemphasized. Pesticide is one of the most pervasive environmental chemical contaminants that have been of increased use due to the compelling need to feed the ever-growing world human and animal population and protect their health. Chlorpyrifos (CPF), a widely used Organophosphate (OP) insecticide has been reported to alter male reproductive hormones and semen characteristics. Apart from acetyl cholinesterase inhibition, the induction of oxidative stress is one of the molecular mechanisms implicated in CPF poisoning. Approach: The present study was aimed at evaluating the effect of vitamin E in mitigating oxidative damage to the pituitary gland and the testis, induced by chronic CPF administration in Wistar rats. Methodology: Twenty adult male Wistar rats divided into 4 groups of 5 rats in each group were used for this study. Group I received soya oil (2 mL kg-1), while Group II was administered vitamin E (75 mg kg-1); Group III was administered CPF only (10.6 mg kg-1~1/8th LD50), while group IV was pretreated with vitamin E (75 mg kg-1) and exposed to CPF (10.6 mg kg-1) 30 min later. The regimens were administered orally by gavages once daily for a period of 15 weeks. At the end of the treatment period, the rats were sacrificed and the pituitary glands and testicular tissues were assayed for the concentrations of Malonaldehyde (MDA) and the activities of Superoxide Dismutase (SOD) and Catalane (CAT). Results: The result showed that the increase in concentrations of pituitary and testicular MDA and a decrease in the activities of SOD and CAT recorded in the group exposed to CPF were ameliorated by pretreatment with vitamin E. Conclusion: This indicates that vitamin E mitigates reproductive toxicity induced by chronic CPF exposure due to its protective antioxidant activity on pituitary glands and the testes.

Clinical, endocrinological and histopathological patterns of infertile Saudi men subjected to testicular biopsy: A retrospective study from a single center.

Purpose:To evaluate the outcome of testicular biopsies as well as the etiology of azoospermia and severe oligospermia in Saudi men referred for tertiary care. To correlate testicular histology with patients’ clinical and hormonal profiles.Materials and Methods:Charts of men subjected to testicular biopsies in the last 10-year period were retrospectively reviewed. Relative history and physical examination findings were reported. Results of male fertility profile tests and semen analysis of at least two ejaculates were collected. Reported histopathology was obtained.Results:Reports of 229 patients were included; 199 (86.9%) with azoospermia and 30 (13.1%) with severe oligospermia. The mean (SD) age was 30.6 (6.4) years. A small right or left testis was reported in 88 (38.4%) and 87 (38%) of the patients, respectively. The mean (SD) testosterone and follicle stimulating hormone (FSH) values were 17.2 (7.2) nmol/L and 13.1 (10.9) IU/L, respectively. Hypospermatogenesis was the most common histology encountered (36.5%), followed by Sertoli cell-only (SCO) histology (31.5%). Low testicular volume (P = 0.000), high FSH (P = 0.001) and high leutenizing hormone (LH) (P = 0.001) were found to be of significantly adverse effect on spermatogenesis. Despite having bilateral small testes, high serum FSH and LH, 24.3% of our patients showed active spermatogenesis.Conclusions:Hypospermatogenesis was the most common pattern of spermatogenic defect in our patients. SCO histology was the most common pattern in patients with small testes, primary testicular failure, primary infertility and azoospermia. Low testicular volume, high FSH and LH are significantly associated with impaired spermatogenesis. Even with severe male factor infertility disorders, infertile men can have some spermatogenesis.

DETECÇÃO DO VÍRUS DA ARTRITE ENCEFALITE CAPRINA NO SÊMEN ATRAVÉS DAS TÉCNICAS DE PCR E NESTED-PCR

RESUMO A Artrite Encefalite Caprina é uma enfermidade de caráter multissistêmico afetando animais de qualquer idade e sexo; causado por um Lentivirus caprino pertencente ao grupo de Lentivirus de Pequenos Ruminantes. Os sintomas conhecidos são leucoencefalomielite, pneumonia intersticial crônica, artrite e mastite intersticial endurativa. Foi descrito que machos soropositivos apresentavam sêmen infectado pelo Lentivirus e processo inflamatório gradual do testículo. A detecção em amostras de sêmen pelas técnicas de PCR e nested-PCR são caracterizadas como métodos de altas especificidade e sensibilidade provendo resultados rápidos. O objetivo do estudo foi detectar, por meio da técnica molecular de PCR e nested-PCR, a presença de DNA pró-viral do Lentivirus caprino em amostras de sêmen de reprodutores criados no Estado de São Paulo. Das 17 amostras, cinco (29,4%) apresentaram a detecção do vírus provando que há a presença de partículas virais no sêmen dos caprinos reprodutores soropositivos a Atrite Encefalite Caprina estudados.

Estrogens and phytoestrogens in male infertility

A time-related negative trend in male reproductive function has been suggested. It has been hypothesized that this is due to exposure to chemicals interfering with the action of sex hormones. Also a negative effect of phytoestrogens on male fertility has been postulated. This review aimed to review the epidemiological evidence of deteriorating male reproductive function and summarize the most recent literature on exposure to endocrine disrupters and phytoestrogens in relation to male fertility and/or semen quality. There is no doubt that the incidence of testicular cancer has increased through the past 50 years, a decline in sperm counts, if any, may have leveled off during the past decade. There are some reports indicating negative association between exposure to certain chemicals and sperm parameters such evidence has not been found for phytoestrogens. The majority of these studies have been limited to assessing postnatal exposure. Although possible negative impact of industrial chemicals and male fertility is an important issue on the research agenda, so far, it has no clinical implications. The future research should focus on looking at the impact of low dose exposure to a mixture of chemicals, two generation studies and gene-environment interaction.

Automated sperm head morphology analyzer for open-source software

Sperm head morphology has been identified as a characteristic that can be used to predict a male's semen quality. In the present study, we have developed an automated sperm head morphology analysis (ASMA) plug-in for open-source ImageJ software (http://rsbweb.nih.gov/ij/). We describe the plug-in's functionality, and confirm its validity for sperm head morphology analysis using fish sperm. Sperm head morphological measurements (length and width) made with the ASMA plug-in did not differ from manual measurements. Using the plug-in to measure sperm head-shaped objects of known size, the associated plug-in error rate was < 0.5%. Brightness and contrast ratios influenced sperm head measurements, suggesting the need for standardized protocols. This plug-in was effective at measuring elliptical (i.e., Atlantic cod) as well as slightly irregular (i.e., Chinook salmon) shaped sperm heads. In conclusion, our ASMA plug-in represents a versatile alternative to costly sperm morphology software.

Does heavy metals pollution affects semen quality in men? A case of study in the metropolitan area of Naples (Italy)

In recent years, a significant increase in the incidence of male infertility has been observed and described in the international literature, raising questions about its causes. Several authors have suggested that exposure to environmental pollution may contribute to a perceived decline in semen quality worldwide. Although several studies have been conducted about the effects on male fertility caused by exposure to heavy metals in the workplace, research on the effects caused by continued exposure to low doses of heavy metals pollution in urban areas is still scarce. The aim of this study is to identify the relationships between high concentrations of heavy metals and male semen quality in the metropolitan area of Naples. We considered only those elements (Al, As, Cd, Cr, Cu, Hg, Mn, Mo, Pb, Sb, Tl, Zn) that previous studies have indicated as possible candidates to have some influence on human semen quality. We measured semen quality among 600 subjects selected from a sample of 1237 men regularly examined at the Andrology Laboratory of the University of Naples “Federico II” for problems related to male fertility. Using statistical methods the semen data (semen volume, sperm concentration, sperm total count, sperm motility, pH) were compared with the geochemical distribution of heavy metals in soils of the Napoli metropolitan area. Results show a strong correlation between anomalous Pb and Sb concentrations and men with poor semen quality. A weaker correlation was also observed with Hg and Zn while the anomalous concentration values of the other elements (Al, As, Cd, Cr, Cu, Mn, Mo and Tl) appear to have no correlation with poor quality of the human semen.

THE IMPACT OF STRESS ON SEMEN QUALITY

Background: Stress is one the most important health and social problems. Psychological stress has long been suspected as having important impact on infertility. Studies on the effects of psychological stress on male fertility, especially semen quality have so far yielded equivocal findings. Methods: The study population consists of 179 men register to infertility clinic in purpose of diagnosis with normal fertility (semen total concentration 15-300 mln/ml) or with little oligozoospermia (semen total concentration 10 do 15 mln/ml). The semen samples was analysed in one laboratory according to the WHO manual for basic semen analysis. The main semen parameters were assessed: volume, motility, % atypical, % of progressive spermatozoa. To asses the occupational stress the General Health Questionnaire 28 (GHQ-28) was used. As a results of this questionnaire we used sum of the points obtain by man taking part in the study and the number of stressful events at work (if the stressful events or situation appeared) announced by studied subjects. Results: The level of stress measured by General Health Questionnaire 28 (GHQ-28) taking into account the number of stressful events, such situations affect semen volume and % of progressive spermatozoa after controlling factor that can have impact on semen quality like: time of couple infertility, abstinence and diseases in the past that can affect fertility. Conclusions: The study confirms that the occupational stress can affect male semen quality, but as there is little studies in those directions the results need to be confirmed. This cohort being assembled will form a basis for further longitudinal observations.

An exploration of the association between male body mass index and semen quality

Obesity is becoming a serious problem, especially in industrialized societies. This study was designed to explore the association between body mass index (BMI) and semen quality. Semen analysis and demographic data were collected from male partners of couples undergoing fertility investigations in a referral fertility centre. Men were classified into groups according to their BMI (A, <18.5; B, 18.5–24.99; C, 25–29.99; D, ⩾30 kg/m 2). Data from 2035 men were analysed using logistic regression. There were 18, 839, 909 and 269 men in groups A, B, C and D, respectively. Taking group B as the reference, adjusted odds ratios (95% CI) for groups A, C and D for semen volume <2 ml were 1.57 (0.49–5.01), 1.06 (0.82–1.38) and 1.69 (1.20–2.38), respectively; for sperm morphology <15%, 1.44 (0.45–4.61), 1.07 (0.86–1.33) and 1.50 (1.06–2.09); for sperm concentration <20 million/ml, 0.46 (0.10–2.07), 1.03 (0.82–1.31) and 1.00 (0.72–1.41); and for motility <50%, 2.62 (0.73–9.45), 0.96 (0.78–1.18) and 0.75 (0.56–1.01). In conclusion, obese men are more likely to have lower semen volume and fewer morphologically normal spermatozoa than men with normal BMI. Obesity is becoming a serious problem, especially in industrialized societies. We designed this study to explore the association between body weight in proportion to height, in men, as expressed by the body mass index (BMI) and semen quality. Semen analysis and demographic data were collected from male partners of couples undergoing fertility investigations in a referral fertility centre. Men were classified into groups according to their BMI: A, <18.5, underweight; B, 18.5–24.99, normal weight; C, 25–29.99, overweight; and D, 330 kg/m 2, obese. Data from 2,035 men were analysed. There were 18, 839, 909 and 269 men in groups A, B, C and D, respectively. Compared with men from group B, normal weight, and taking into account other factors besides BMI that may affect semen quality in the analysis, the adjusted odds ratios (95% CI) for groups A, C and D to have a semen volume <2 ml were 1.57 (0.49–5.01), 1.06 (0.82–1.38) and 1.69 (1.20–2.38), respectively, for sperm morphology <15%, 1.44 (0.45–4.61), 1.07 (0.86–1.33) and 1.50 (1.06–2.09), for sperm concentration <20 million /ml, 0.46 (0.10–2.07), 1.03 (0.82–1.31) and 1.00 (0.72–1.41) and for motility <50%, 2.62 (0.73–9.45), 0.96 (0.78–1.18) and 0.75 (0.56–1.01). In conclusion, obese men are more likely to have lower semen volume and fewer morphologically normal spermatozoa than men with normal BMI.

MP-07.02 Association of Polymorphisms in the Estrogen Receptors Alpha and Beta (ESR1, ESR2) with the Occurrence of Male Infertility and Semen Parameters

MP-07.02 Association of Polymorphisms in the Estrogen Receptors Alpha and Beta (ESR1, ESR2) with the Occurrence of Male Infertility and Semen Parameters

MP-07.01 Relationship Between Genetic Polymorphisms of Methylenetetrahydrofolate Reductase (C677T, A1298C, and G1793A) as Risk Factors for Idiopathic Male Infertility

In recent years, interest has increased in the role of homocysteine and folate, as modulators of fertility status. The human methylenetetrahydrofolate reductase (MTHFR) gene plays a crucial role in folate metabolism. Data regarding the influence of MTHFR gene polymorphisms on male fertility status are scarce and conflicting. We determined associations between three MTHFR gene polymorphisms (C677T, A1298C, and G1793A), serum folate and total homocysteine (tHcy) levels, with male fertility status and semen parameters.

Does oocyte morphology affects the clinical outcome in a shared egg donor program?

The aim of this study was to evaluate the fertilization rate, embryo quality and pregnancy rate considering different patterns of oocyte morphology in a shared oocytes donation program. Retrospective controlled study. Five hundred forty-nine cycles of shared oocyte donation performed at CEGYR (Jan-Oct, 2010) were analyzed. It was compared the results from cycles using oocytes with abnormal morphology: cytoplasmic granules, presence of cytoplasmic vacuoles, increased perivitelline space (PS) and thickened zona pellucida (ZP) versus versus cycles with normal morphology. It was considered cohorts with more than 80% of one oocyte morphology pattern. Fertilization rate, embryo quality, clinical pregnancy and implantation rates were evaluated. Cases with severe male factor and donor semen were excluded. Statistical analysis was performed using Chi-Square test. Obtained results are shown in table 1.Table 1NormalGranulatedVacuolatedIncreased PSThick ZPCycles (459)1341681611526MII oocytes (No.)741106990711140MII oocytes/cycle5.56.45.66.25.4Fertilization rate (%)564(76.1)756(70.7)a72(80.0)505(71.0)a105(75.0)No. of embryo transfer cycles115146159722ET cancellation (%)19(14.2)22(13.1)1(6.3)18(15.7)4(15.3)No. of embryos transferred2282882819344Embryos transferred/cycle1.981.971.871.982.0Embryo quality (I-II)(%)42.544.435.739.956.8Embryo quality (III)(%)53.553.160.756.543.2Embryo quality (IV)(%)4.02.53.63.60BHCG (+) (%)61(53.04)75(51.4)7(46.7)52(53.6)12(54.5)Clinical Pregnancy (%)52(45.2)69(47.2)7(46.7)49(50.5)12(54.5)Implantation rate (%)61(26.8)92(31.9)8(28.6)68(35.2)17(38.6)a(P<0.05) Open table in a new tab a(P<0.05) Oocytes with cytoplasmic granulation and increased PS showed a significantly lower fertilization rates, but this feature do not affect the pregnancy and implantation rates. Oocyte morphology does not seem to affect the outcome of ICSI in patients from shared oocyte donation program.

SP4-25 Population survey of semen quality in young Scottish men

IntroductionFor years concerns have been raised that male semen quality is declining globally, and that this is a birth cohort effect. However, there has been a degree of subject selection...

Plastics and Food Sources: Dietary Intervention to Reduce BPA and DEHP

Purchasing fresh, unpackaged foods and avoiding the use of plastic food processing and storage equipment may help consumers minimize their exposure to bisphenol A (BPA) and bis(2-ethylhexyl) phthalate (DEHP), according to a small but systematic study of associations between diet and people’s levels of these chemicals [EHP 119(7):914–920; Rudel et al.]. At the time of this January 2010 study, BPA and DEHP were used widely in food packaging, including cans, plastic wraps, and food storage containers.1 Evidence from in vitro and animal studies demonstrates BPA’s potential to disrupt endocrine function in a number of organ systems. Animal studies have linked exposure to DEHP to inhibition of testosterone synthesis and adverse effects on the developing male reproductive system. Some epidemiologic evidence also links urinary levels of phthalate metabolites to effects on boys’ reproductive development, male hormone levels, semen quality, and neurobehavioral end points. Although some scientists believe diet is likely to be a major source of exposure to BPA and DEHP, few empirical data exist to verify this belief. One of the stated goals of the current study was to assess the relative importance of food packaging as a source of exposure to these chemicals. BPA and DEHP are relatively easy to study because they have short biological half-lives and exposure biomarkers that can be measured in urine. The study involved five 4-person families, including adults and children, who were chosen in part because they reported frequently eating canned foods. Urine samples were collected over 8 days. On days 3–5 family members consumed only food prepared by a caterer who avoided using plastic (including plastic utensils and storage containers) in preparing and packaging the meals and snacks made from fresh ingredients. Families were given stainless steel water bottles and lunch boxes and advised to use only the containers provided. Coffee drinkers were instructed to use a French press or ceramic drip in place of a plastic coffee maker. When consuming their customary diets, family members’ urine levels of biomarkers for both BPA and DEHP were in the range of the general U.S. population’s, as estimated by the Centers for Disease Control and Prevention’s National Health and Nutrition Examination Survey program. During the time the families were on the fresh-food diet, the geometric mean concentration of BPA dropped by 66%, and mean concentrations of DEHP metabolites decreased by 53–56%. The researchers note they cannot determine exactly which changes in food sourcing and handling caused the observed exposure changes. In addition, their intervention did not completely eliminate all sources of BPA and DEHP. They state food contamination may occur during premarket processing of whole foods or from the presence of phthalates and BPA in the environment where the food originates.

Seminal Advances in Immunology of Reproduction

INTRODUCTION The paper by Guerin et al. from Sarah Robertson’s group in this issue of Biology of Reproduction reports a major advance in our understanding of the mechanism(s) by which male semen may protect the implanting semi-allogeneic embryo against rejection by maternal innate and adaptive immune defenses. BALB/c (H-2) males were used with C56BL6 (H-2) females [1]. Following mating, the lymph nodes draining the uterus, (draining lymph nodes, DLN or para-aortic lymph nodes PALN) enlarge; this enlargement is greater when the male is allogeneic. i.e. histoincompatible with the female, and generation of anti-paternal cytotoxic T cells is suppressed [2]. The sequence of events is depicted in Figure 1. Seminal plasma (SP) and spermatozoa (S) ejaculated into the uterine lumen at the time of mating on gestation day 0 (GD 0) act on the uterine epithelium, sub-endothelial macrophages (Mph) and dendritic cells (DC). This leads to trafficking of cells (and perhaps the predominant chemokine CCL19) via afferent lymphatics to para-aortic lymph nodes draining the uterus (DLN or PALN). There, CCL19 recruits circulating regulatory T cells (Treg, identified by the presence of FOXP3) acting via the CCR7 receptor (and possibly CCR5) . DC may present antigens from SP (blue dots) or spermatozoa (red dots). Activated Treg cells exit the lymph nodes and home tothe uterine lining by GD day 3.5, again mediated for the most part by CCL19 binding to CCR7. Interestingly, measuring mRNA for Foxp3 showed an increase that was reduced by about half if SVX males lacking seminal plasma (SP) or VAS males lacking spermatazoa (S) were used, suggesting spermatozoa could activate Foxp3 mRNA in uterine cells without significantly increasing CCL19-dependent Treg cell recruitment, although both S+SP were required for maximal activation. On GD 4.5, the semi-allogeneic blastocyst, potentially susceptible to rejection directed against minor paternal histocompatibility antigens [2], implants. Guerin et al. argue that the regional generation and local recruitment of Treg cells to the uterus in advance of implantation acts to protect the implanting embryo against maternal immune rejection. In support of this contention, they noted an increase in CD4CD25 cells in the DLN that did not express FOXP3 and which could represent activated effector T cells.

Phthalates exposure of Chinese reproductive age couples and its effect on male semen quality, a primary study

Phthalates are suspected of having adverse effects on androgen-regulated reproductive development in animals and may be toxic for human sperm. The purposes of our study were to investigate the general exposure of a Chinese reproductive age cohort to these ubiquitous pollutants and to assess their potential effect on semen quality.Six phthalate metabolites, monomethyl phthalate (MMP), monoethyl phthalate (MEP), monobutyl phthalate (MBP), monobenzyl phthalate (MBzP), mono-2-ethylhexyl phthalate (MEHP), and mono-2-ethyl-5-oxohexyl phthalate (MEOHP) were measured in spot urines of 150 individuals recruited from a Chongqing, China, reproductive institute. The questionnaire and clinical data were evaluated, and the correlations of phthalate exposure and semen qualities like semen volume, sperm concentration, motility and sperm motion parameters, were determined by multiple logistic regression analysis.The creatinine adjusted average concentrations for MMP, MEP, MBP, MBzP, MEHP and MEOHP were 41.3, 300, 41.0, 0.78, 2.99 and 3.90μg/g, respectively. After adjustment for age, body mass index (BMI), abstinence, smoking, drinking, and education, there was a borderline-significant dose–response relationship between MBP and sperm concentration, with odd ratios (ORs) 1.0, 6.8 and 12.0 for increasing exposure tertiles (p=0.05). Although the dose–response relationships for MMP and MEP versus sperm concentration were not significant, a significant positive correlation between MEP and straight-line velocity of sperm motion was observed.The present data may imply some effects of phthalate exposure on semen. However, due to the small sample size, our finding needs to be confirmed on a larger population.

Relationship Between Genetic Polymorphisms of Methylenetetra hydrofolate Reductase (C677T, A1298C, and G1793A) as Risk Factors for Idiopathic Male Infertility

The human methylenetetrahydrofolate reductase (MTHFR) gene plays a crucial role in folate metabolism. Data regarding the influence of MTHFR gene polymorphisms on male fertility status are scarce and conflicting. We determined associations between 3 MTHFR gene polymorphisms (C677T, A1298C, and G1793A), serum folate, and total homocysteine (tHcy) levels, with male fertility status and semen parameters. MTHFR genotypes were determined using polymerase chain reaction restriction fragment length polymorphism (PCR-RLFP) technique and serum tHcy, folate, and vitamin B12 concentrations were measured in 164 men with idiopathic infertility and 328 healthy participants. There was a significant difference in genotype frequency distribution of MTHFR C677T polymorphism between infertile patients and controls (P = .004). The 677T allele carriers (TC or TT) had a significantly increased risk of infertility compared with the CC homozygotes (odds ratio [OR] 1.60, 95% confidence interval [CI] 1.21-2.75, and OR = 2.68, 95% CI = 1.84-3.44, respectively), in a logistic regression model after adjustment for confounding factors. Men with the 677T, 1298C, and 1793G alleles showed significantly higher serum tHcy and lower folate levels (all Ps < .01). We found a positive correlation between serum folate concentrations and sperm density (r = .74, P = .001), percentage of sperm with progressive motility (r = .68, P = .001), as well as percentage of sperm with normal morphology (r = .72, P = .001). MTHFR C677T polymorphism is associated with an increased risk of idiopathic male infertility. Further study on the biologic role that this polymorphism plays in the development of infertility may lead to better understanding of the etiology of impaired spermatogenesis.

The effects of acquired paternal obesity on the next generation

The effects of acquired paternal obesity on the next generation