Standards in semen examination: publishing reproducible and reliable data based on high-quality methodology.

Biomedical science is rapidly developing in terms of more transparency, openness and reproducibility of scientific publications. This is even more important for all studies that are based on results from basic semen examination. Recently two concordant documents have been published: the 6th edition of the WHO Laboratory Manual for the Examination and Processing of Human Semen, and the International Standard ISO 23162:2021. With these tools, we propose that authors should be instructed to follow these laboratory methods in order to publish studies in peer-reviewed journals, preferable by using a checklist as suggested in an Appendix to this article.

Sperm Cohort-Specific Zinc Signature Acquisition and Capacitation-Induced Zinc Flux Regulate Sperm-Oviduct and Sperm-Zona Pellucida Interactions.

Building on our recent discovery of the zinc signature phenomenon present in boar, bull, and human spermatozoa, we have further characterized the role of zinc ions in the spermatozoa's pathway to fertilization. In boar, the zinc signature differed between the three major boar ejaculate fractions, the initial pre-rich, the sperm-rich, and the post-sperm-rich fraction. These differences set in the sperm ejaculatory sequence establish two major sperm cohorts with marked differences in their sperm capacitation progress. On the subcellular level, we show that the capacitation-induced Zn-ion efflux allows for sperm release from oviductal glycans as analyzed with the oviductal epithelium mimicking glycan binding assay. Sperm zinc efflux also activates zinc-containing enzymes and proteases involved in sperm penetration of the zona pellucida, such as the inner acrosomal membrane matrix metalloproteinase 2 (MMP2). Both MMP2 and the 26S proteasome showed severely reduced activity in the presence of zinc ions, through studies using by gel zymography and the fluorogenic substrates, respectively. In the context of the fertilization-induced oocyte zinc spark and the ensuing oocyte-issued polyspermy-blocking zinc shield, the inhibitory effect of zinc on sperm-borne enzymes may contribute to the fast block of polyspermy. Altogether, our findings establish a new paradigm on the role of zinc ions in sperm function and pave the way for the optimization of animal semen analysis, artificial insemination (AI), and human male-factor infertility diagnostics.

The activation of the chymotrypsin-like activity of the proteasome is regulated by soluble adenyl cyclase/cAMP/protein kinase A pathway and required for human sperm capacitation.

One of the first events of mammalian sperm capacitation is the activation of the soluble adenyl cyclase/cAMP/protein kinase A (SACY/cAMP/PKA) pathway. Here, we evaluated whether the increase in PKA activity at the onset of human sperm capacitation is responsible for the activation of the sperm proteasome and whether this activation is required for capacitation progress. Viable human sperm were incubated with inhibitors of the SACY/cAMP/PKA pathway. The chymotrypsin-like activity of the sperm proteasome was evaluated using a fluorogenic substrate. Sperm capacitation status was evaluated using the chlortetracycline assay and tyrosine phosphorylation. To determine whether proteasomal subunits were phosphorylated by PKA, the proteasome was immunoprecipitated and tested on a western blot using an antibody against phosphorylated PKA substrates. Immunofluorescence microscopy analysis and co-immunoprecipitation (IPP) were used to investigate an association between the catalytic subunit alpha of PKA (PKA-Cα) and the proteasome. The chymotrypsin-like activity of the sperm proteasome significantly increased after 5 min of capacitation (P < 0.001) and remained high for the remaining incubation time. Treatment with H89, KT5720 or KH7 significantly decreased the chymotrypsin-like activity of the proteasome (P < 0.001). IPP experiments indicated that PKA inhibition significantly modified phosphorylation of proteasome subunits. In addition, PKA-Cα colocalized with the proteasome in the equatorial segment and in the connecting piece, and co-immunoprecipitated with the proteasome. This is the first demonstration of sperm proteasome activity being directly regulated by SACY/PKA-Cα. This novel discovery extends our current knowledge of sperm physiology and may be used to manage sperm capacitation during assisted reproductive technology procedures.

Effects of three long-acting reversible contraceptive methods on HIV target cells in the human uterine cervix and peripheral blood.

BACKGROUND: Hormonal contraceptives, particularly depot medroxyprogesterone acetate (DMPA), have been reported to be associated with substantially enhanced HIV acquisition; however, the biological mechanisms of this risk remain poorly understood. We aimed to investigate the effects of different hormonal contraceptives on the expression of the HIV co-receptors, CXCR4 and CCR5, on female endocervical and peripheral blood T cells. METHODS: A total of 59 HIV-negative women were enrolled, including 15 initiating DMPA, 28 initiating a levonorgestrel-releasing intrauterine device (LNG-IUD) and 16 initiating an etonogestrel (ETG)-delivering vaginal ring. Peripheral blood and endocervical cytobrush specimens were collected at enrollment and 3-4 weeks after contraception initiation to analyze the expression of CXCR4 and CCR5, on CD4+ and CD8+ T cells using flow cytometry. RESULTS: Administration of DMPA increased the percentages of CD4+ and CD8+ T cells expressing CCR5 in the endocervix but not in the peripheral blood. Administration of the LNG-IUD or the ETG vaginal ring did not affect the percentages of T lymphocytes expressing CXCR4 or CCR5 in the female cervix or peripheral blood. CONCLUSIONS: Increase in the percentage of endocervical T cells expressing CCR5 upon DMPA exposure provides a plausible biological explanation for the association between DMPA use and an elevated risk of HIV infection.

Semen and reproductive hormone parameters in fertile men with and without varicocele.

Although varicoceles are a widely accepted identifiable male factor in infertile couples, the benefit of varicocele repair in improving pregnancy and live birth rates remains uncertain. The Study for Future Families obtained semen and reproductive hormone samples from US men whose partners were currently pregnant. In our analysis cohort of 709 men, a varicocele was detected by clinical examination in 56 (8%) of men. Men with varicocele had smaller left testis, and lower total and total motile sperm counts than men without varicocele. Gonadotropin levels were higher as well in men with varicocele. Interestingly, testosterone levels were also slightly higher in men with varicocele. Despite these differences, there was no difference between the groups in the time to achieve the study pregnancy or percentage of men with a previous pregnancy. We conclude that even in fertile men, varicoceles are associated with some degree of testicular hypofunction. This would support current recommendations to consider varicocele repair in male partners in infertile couples who demonstrate both a varicocele and abnormal semen parameters and after evaluation for treatable female factors.

Non-indicated use of prophylactic antibiotics in gynaecological surgery at an academic tertiary medical centre.

Surgical site infections (SSI) are the most common surgical complication. Perioperative antibiotics can reduce SSI when used properly. Despite guidelines from The American College of Obstetrics and Gynecology, non-indicated antibiotic use is widespread which exposes women to unnecessary risks. This study represents a quality improvement analysis assessing surgeon compliance with established guidelines regarding antibiotic use in gynaecological surgery. This is a single centre, retrospective study examining gynaecological procedures over two years. Cases were identified using Current Procedure Terminology codes. Perioperative antibiotics were used contrary to published guidelines in 199 of 1046 cases. Three variables were independently associated with inappropriate administration of perioperative antibiotics: entrance into abdominal cavity, higher EBL, and longer procedures. Impact statement Overuse of antibiotics has unintended consequences including allergic sequelae, extended length of hospital stay, increased healthcare costs, and the formation of antibiotic-resistant organisms. Antibiotic stewardship programmes have been shown to reduce the number of resistant pathogens, decrease incidence of Clostridium difficile colitis, and decrease length of hospital stay without increasing infection rates. Further outcomes-based research is needed regarding the use of antibiotic stewardship programmes in gynaecological surgery.

Introduction to Medication Effects on Male Reproduction.

The over-arching goal of this volume is to help infertility practitioners evaluate and manage their patients with poor semen quality. Medications can negatively impact on male reproduction and these effects are of increasing concern. People world-wide are using more medications than in the past, including men of childbearing age. In addition, men are fathering children later in life than previously, which is associated with greater medication use in the reproductive population. Finally, people are experiencing more chronic disease at earlier ages, particularly in developed countries. Taken together, these factors have increased the number of prescribed and over-the-counter (OTC) drugs being taken by men attempting fatherhood. There is some evidence in the literature that medications, even some common OTC medications, can negatively impact male reproduction, and yet, medication use is inadequately addressed in the evaluation of male infertility and fertility plans are rarely considered by providers before prescribing medications. In this volume, we systematically consider medications being used world-wide, focusing on those that might cause poor semen quality in men with otherwise idiopathic infertility. Extensive tables are provided in this volume that summarize the research for each specific medication, and it is our hope that these tables will be useful in day-to-day counseling of infertility patients and of men desiring fertility. Although some specialist practitioners are aware that there are pharmacological negative effects on male fertility, most practitioners are not, and the published evidence is surprisingly sparse. We hope that this volume will encourage our readers to conduct robust, well-designed studies to inform clinical practice.

Challenges of Obtaining Evidence-Based Information Regarding Medications and Male Fertility.

In the clinic, the existing literature is insufficient to counsel our infertile men on medication use. Most studies have flaws that limit their application to evidence-based practice. In this chapter, we discuss the limitations of the current literature and the challenges to designing more useful studies. Among the most important weaknesses of existing studies is lack of power; that is, too few men are included to draw conclusions about the existence and size of medication effects. Adequate power is particularly important when confirming an absence of medication effect. Bias is also a problem in most studies. Early studies were rarely randomized, placebo-controlled, or blinded; a common example is patients receiving different medication regimes based on the severity of their symptoms-making it impossible to attribute differences between treated and untreated men to the medications. Additional bias is introduced by failing to include other factors that influence the outcome in the experimental design. A uniform population amenable to randomization and placebo-control are experimental species, and useful information has been gained from these models. However, application to humans is limited by differences from other species in route of drug administration, absorption of the drug, concentration in the male genital tract tissues, and genital tract physiology. To a lesser degree, there is variation among individual men in their response to drugs. In addition, drugs in the same class may have different effects, limiting the applicability of data across drugs of a single class. Complicating matters further, a toxic medication may seem to improve fertility endpoints by improving a disease condition that diminishes fertility. Finally, drug interactions have not been studied, and actual fertility data (pregnancy/fecundity) in humans are rare. A healthy dose of skepticism is warranted when evaluating studies of medications and male reproductive health.

Male Reproductive Functions Disrupted by Pharmacological Agents.

In this chapter, we review the male reproductive functions disrupted by medications. Medications can affect the hypothalamic-pituitary-gonad axis, acting as endocrine disrupting chemicals (EDCs). Disturbances may be directly at androgen receptors, modifying the activity of endogenous androgens at the target tissue, or may disrupt feedback loops at the hypothalamus or pituitary resulting in modification of gonadotropin release. Impaired testosterone production and/or spermatogenesis result. Other EDC activities can be indirect via effects on levels of prolactin (PRL), estrogen, cortisol, thyroid hormone, or sex hormone binding globulin (SHBG). Appropriate regulation of these hormones and SHBG are essential for normal reproductive function. An increase in circulating PRL levels is a common adverse medication effect. The consequence is lower gonadotropin and testosterone secretion. Drugs can also have direct toxicity on the seminiferous tubule epithelium, including effects on Leydig cells, Sertoli cells, or germ cells. In some cases, spermatogenesis is severely impaired. After leaving the testis, sperm spend a week or more in the epididymis. It is clear from the timing of some drug effects that sperm are damaged during epididymal transit. There can also be impairment of the ejaculatory reflex, resulting in alterations of emission or expulsion of semen. Even after ejaculation, exposure to seminal plasma can alter sperm function, and some drugs may affect sperm at this stage. The most critical effects on male reproduction are decreased fertility and/or health effects on offspring. These endpoints have received little research attention. Another consideration is the metabolism of drugs. Medications may become more toxic if metabolic systems are suboptimal due to comorbid conditions.

Exogenous Androgens and Male Reproduction.

Due in part to aggressive marketing, the prevalence of exogenous androgen use has increased to disturbing levels. Prescribing practitioners are often unaware of the severity of the anti-fertility effects. Exogenous androgens should only be prescribed if hypogonadism has been established by appropriate investigation, and preferably the patient does not intend to father a child. There are alternative medications, or combinations of medications, that can be used if hypogonadism is present and fertility is desired.It is somewhat counterintuitive that testosterone treatment will decrease or abolish fertility. Exogenous testosterone inhibits spermatogenesis by removing the feedback response to low testosterone at the hypothalamus and pituitary. This results in reduced synthesis and secretion of gonadotropins required to stimulate endogenous testosterone production and to support spermatogenesis. It is important to realize that the normal testicular levels of testosterone are approximately 100 times the concentration in circulation. These high levels are required locally to support spermatogenesis. So even with circulating androgen levels within the normal range, spermatogenesis fails due to insufficient gonadotropin and local testosterone support. Androgenic herbal supplements and illicit use of anabolic steroids have contributed to this serious challenge in the treatment of infertile men. Most men will recover normal spermatogenesis after cessation of exogenous testosterone treatment, but this requires 6 months or more in most men. In rare cases fertility is permanently impaired.

Phosphodiesterase Inhibitors (PDE Inhibitors) and Male Reproduction.

The nonspecific PDE inhibitors, particularly the methylxanthines: caffeine, pentoxifylline (PTX), and theophylline, are known to stimulate sperm motility in vitro and have been used to treat sperm prior to insemination. The in vivo effects are less dramatic. A beneficial effect of caffeine, which is a constituent of some medications, remains controversial. Very high doses of caffeine do have negative effects on fertility endpoints in men and experimental species. The specific PDE5 inhibitors, particularly sildenafil and tadalafil, are prescribed for erectile dysfunction, as well as pulmonary hypertension, lower urinary tract symptoms, and premature ejaculation. PDE5 is expressed throughout the contractile tissues of the male reproductive tract, generally increasing contractility. Some PDE5 inhibitors tend to increase circulating testosterone levels somewhat. For short-term exposure consistent with use prior to intercourse, there appears to be minimal effects on semen quality. Several large, randomized controlled trials (RCTs) in healthy men have not found adverse effects of long-term use of these drugs on semen quality. RCTs in infertile men have demonstrated a modest increase in semen quality. Animal studies at human equivalent doses (HED) have produced similar results in young males, but a study in aging male rats found progressive decreases in epididymal sperm quality accompanied by consistent degeneration of the seminal tubules suggesting that studies in older men might be warranted. A concerning study in mice found lower fertilization rates in males treated with HED of sildenafil and mated the next day to untreated females than for control males. Fertility studies in humans are needed.

Pain Medications and Male Reproduction.

The increasing use of opioid medications has become a crisis in developed countries. The profound negative effects of opioids on male reproduction are well known, but this topic is absent from the current conversations about these medications. In the fertility clinic, a significant proportion of our patients are using opioids for pain management, and the options for these men are unclear. Opioids exert their negative effects by a variety of mechanisms. At high doses, testosterone levels fall significantly and hypogonadism is seen. In part, this results from increased prolactin and inhibition of gonadotropin production/secretion by the pituitary. However, negative effects on the testis are seen even in the absence of decreased androgen levels. As we review in this chapter, Leydig and germ cells produce endogenous opioids, and receptors for these substances are present throughout the testis. For example, endogenous opioids produced by Leydig and germ cells provide paracrine inhibition at Sertoli cell receptors, decreasing the production of androgen binding protein, which is required for intra-testis transport of androgens. Morphine also increases the expression of aromatase in the brain and testis and acts directly on the testis and germ cells to decrease testicular function. Exogenous opioids in men reduce semen quality, including increased DNA fragmentation. All opioids have these effects, but less damage is caused by lower doses, shorter-acting opioids, and by some drugs with mixed receptor activity, such as tramadol and tapentadol. The non-steroid anti-inflammatory drugs (NSAIDS) have much less effect on the male reproductive system, although there is a paucity of human studies. Paracetamol has been shown to cause sperm abnormalities, including DNA fragmentation, and to increase time to pregnancy and may prove to be of greater concern. In rodents, paracetamol has negative impacts on seminiferous tubule histology and fertility. Robust, well-designed studies in humans are needed.

5α-Reductase Inhibitors (5ARIs) and Male Reproduction.

The 5ARIs, finasteride and dutasteride, are used to treat benign prostate hyperplasia and lower urinary tract symptoms. At much lower doses, 5ARI treatment reduces male hair loss. These drugs inhibit the conversion of testosterone to the more active dihydrotestosterone (DHT). In men taking these medications, DHT levels are reduced by some 90% while testosterone levels remain relatively stable. Well known for their negative effects on libido and erectile function, 5ARIs also cause ejaculatory dysfunction in some men, having the potential to decrease semen quality. In fact, some studies of men treated with these drugs have reported lower total sperm count, along with lower sperm motility, although the changes are probably insufficient to reduce fertility in men with normal semen before treatment. There is a population of men with more severely decreased sperm numbers; as low as 10% of pretreatment values. Fewer studies have looked at the lower doses used for male alopecia, indicating little affect in men with normal semen quality, but a negative effect on sperm numbers in men with oligozoospermia. There have been no studies looking at fertility endpoints for these medications.

Psychotropics and Male Reproduction.

Psychotropic drugs, including antidepressants, antipsychotics, and anticonvulsants, all have negative effects on sexual function and semen quality. These adverse events vary among men and are less pronounced for some medications, allowing their effects to be managed to some extent. Use of specific serotonin reuptake inhibitors (SSRIs) is prevalent in men of reproductive age; and application to treat premature ejaculation increases the number of young men on SSRI therapy. Oxidative damage to sperm can result from prolonged residence in the male reproductive tract. The increase in ejaculatory latency seen with SSRIs likely underlies some of their negative effects on semen quality, including higher sperm DNA fragmentation, seen in all SSRIs evaluated thus far. These medications increase prolactin (PRL) levels in some men, and this is often credited with inhibitory effects on male reproduction; however, testosterone levels are generally normal, reducing the likelihood of direct HPG axis inhibition by PRL. The tricyclic antidepressants have also been shown to increase PRL levels in some studies but not in others. The exception is the tricyclic antidepressant clomipramine, which profoundly increases PRL levels and may depress semen quality. Other antidepressants modulating synaptic levels of serotonin, norepinephrine, and/or dopamine may have toxicity similar to SSRIs, but most have not been evaluated. In limited studies, norepinephrine-dopamine reuptake inhibitors (NDRIs) and serotonin agonist/reuptake inhibitors (SARIs) have had minimal effects on PRL levels and on sexual side effects. Antipsychotic medications increase PRL, decrease testosterone, and increase sexual side effects, including ejaculatory dysfunction. The greatest evidence is for chlorpromazine, haloperidol, reserpine, risperidone, and thioridazine, with less effects seen with aripiprazole and clozapine. Remarkably few studies have looked at antipsychotic effects on semen quality, and this is an important knowledge gap in reproductive pharmacology. Lithium increases PRL and LH levels and decreases testosterone although this is informed by few studies. The anticonvulsants, many used for other indications, generally decrease free or bioavailable testosterone with variable effects on the other reproductive hormones. Valproate, carbamazepine, oxcarbazepine, and levetiracetam decrease semen quality; other anticonvulsants have not been investigated for this adverse reaction. Studies are required evaluating endpoints of pregnancy and offspring health for psychotropic medications.

Cardiovascular/Pulmonary Medications and Male Reproduction.

Cardiovascular and respiratory medications are used by men of reproductive age although use of the former is most prevalent in advanced age. Many of these drugs have been associated with sexual dysfunction, including erectile and ejaculatory dysfunction, but for most there is insufficient evidence to link their use with testicular dysfunction, reduced semen quality or infertility. Some exceptions are the irreversible α1-adrenergic antagonist phenoxybenzamine, which carries a high risk of retrograde ejaculation; the specific α1A-adrenergic antagonists silodosin and tamsulosin, used primarily to treat BPH/lower urinary tract symptoms, which can cause retrograde ejaculation; and the peripheral ß1-adrenergic antagonist atenolol, used to treat hypertension, which may decrease testosterone/free-testosterone levels. In this chapter, we review the evidence available regarding adverse reactions on male reproduction of adrenergic receptor agonists/antagonists, calcium channel blockers, angiotensin converting enzyme (ACE) inhibitors, diuretics, digoxin, and hydralazine. For some of these medications, there is some evidence for male reproductive effects, along with some solid work in experimental and companion animal species suggesting negative effects. In contrast, and of special note, are calcium channel blockers, which have long been included on lists of medications with the potential to cause male infertility. This turns out to be a good example of a substance with profound effects on sperm function in vitro, but with limited evidence for in vivo effects on semen quality or fertility, even in experimental species. We hope that the evidence provided in this chapter will stimulate additional studies for these important classes of medications.

Antimicrobials and Male Reproduction.

Antibiotics have long been suspected of contributing to male infertility; however, there are remarkably limited data to support this premise. A major challenge for evaluating antibiotic effects is that the diseases they treat often have negative impacts on male reproduction, so treatment with the antimicrobial can improve reproductive endpoints. This is particularly true for diseases of the male reproductive tract. As a class, anti-parasitic drugs are toxic to eukaryotic cells and have significant potential for reproductive toxicity. A variety of these medications are also used in companion and food animal species; in this chapter we review the literature on anti-parasitic drugs on male reproduction in these species. In humans, only niridazole has been shown to cause reversible spermatogenic arrest in 20 men with schistosomiasis. Of the antifungal medications, ketoconazole has been shown in some studies to transiently decrease testosterone levels in men, but work is lacking for semen quality or fertility. We review studies of antibacterial medications in the chapter, with some minimal human data available for decreased semen quality in men taking nitrofurantoin, ciprofloxacin, ofloxacin, or sulfamethoxazole. These and some other antibacterials have been studied in other species with results suggestive of negative impacts on male fertility endpoints. In light of the common assumption of reproductive toxicity for antimicrobial medications, and the decided lack of supporting evidence, there is a substantial need for well-designed clinical trials in this area.

Antivirals and Male Reproduction.

The use of antiviral medications has increased with the recognition and treatment of HIV infections, and these drugs are the main focus of this chapter. HIV has become a chronic disease, and many men with HIV desire children. The disease itself has profound negative effects on semen quality, as does infection with hepatitis C virus (HCV), so treatment with antivirals generally improves semen quality in men with longer duration of infection and/or greater symptoms. Several changes in medical practice have allowed studies of pharmacopathology of antiviral medications and brought focus on medication effects in asymptomatic men: (1) the successful practice of specialized sperm washing of asymptomatic men with HIV infection for insemination of their HIV-negative partner; (2) the recommendation that men begin anti-retroviral treatment before HIV symptoms appear; and (3) the recommendation that men without HIV infection who have HIV-seropositive partners take HIV prophylaxis. Early cases of HIV infection were generally treated by monotherapy with the nucleoside analog reverse transcriptase inhibitor (NRTI) zidovudine (AZT). Currently, men with HIV infections take combination anti-retroviral therapy (cART), involving three or more medications, making it difficult to assess the toxicity of individual medications. In general, zidovudine alone or cART have minimal negative effects on semen quality; the most common being decreased rapid swimming of motile sperm. We review studies with other outcomes and animal studies in this chapter. Peginterferon-α, which is utilized together with ribavirin to treat HCV, does appear to decrease testosterone levels and semen quality although studies showing these effects have been small. Antiviral medications used to treat viral infections other than HIV and HCV have received little experimental attention for male reproductive effects, even in experimental species.

Immunosuppressants and Male Reproduction.

Prolonged use of immunosuppressant medications is occasionally seen in infertile men with chronic inflammatory conditions; autoimmune disorders; or an organ or hematopoietic stem cell transplant. Chronic inflammation impacts negatively on male reproductive endpoints, so immunosuppressant therapy can produce improvements. Corticosteroids have been used to treat antisperm antibodies and even as an empirical treatment for male infertility in general. Trials of these methods have provided mixed results on semen quality and fertility, with improvement, no change and negative effects reported by different investigators. In a substantial number of observational studies, patients on long-term therapy with prednisone for chronic inflammatory disease, testosterone levels were lower compared to untreated controls, though randomized controlled trials have not been conducted. Similarly decreases in testosterone have been reported in men receiving corticosteroids to minimize transplant rejection; however, most were treated with multiple immunosuppressive medications that may have contributed to this effect. A large number of trials of healthy men treated with corticosteroids have shown some disruption in reproductive hormone levels, but other studies reported no effect. Studies in monkeys, rats (at human equivalent dose), cattle, sheep, and horses have shown endocrine disruption, including low testosterone with dexamethasone treatment. Of the cytostatic immunosuppressives, which have high potential for cellular damage, cyclophosphamide has received the most attention, sometimes lowering sperm counts significantly. Methotrexate may decrease sperm numbers in humans and has significant negative impacts in rodents. Other chemotherapeutic drugs used as immunosuppressants are likely to impact negatively on male fertility endpoints, but few data have been collected. The TNF-α Inhibitors have also received little experimental attention. There is some evidence that the immunophilin modulators: cyclosporine, sirolimus, and everolimus cause endocrine disruption and semen quality impairment. As we review in this chapter, results in experimental species are concerning, and well-designed studies are lacking for the effects of these medications on reproductive endpoints in men.

Miscellaneous Drugs and Male Reproduction.

In addition to main categories of medications believed to have negative impacts on male reproduction, there are a number of miscellaneous drugs with some evidence for such adverse reactions. Because of its widespread use and over-the-counter availability, the H2 receptor antagonist cimetidine is most concerning. As a competitive antagonist at androgen receptors, it can impact the HPG axis and semen quality. In this chapter, we review the studies of this drug and other histamine H2 receptor antagonists in men and experimental species. Several other medications are concerning and the evidence for negative effects on reproduction are covered: colchicine, domperidone, hydroxyurea, metformin, metoclopramide, mifepristone, retinoids, and statins.

Guidelines for risk reduction when handling gametes from infectious patients seeking assisted reproductive technologies.

According to the Americans with Disabilities Act (1990), couples with blood-borne viruses that lead to infectious disease cannot be denied fertility treatment as long as the direct threat to the health and safety of others can be reduced or eliminated by a modification of policies or procedures. Three types of infectious patients are commonly discussed in the context of fertility treatment: those with human immunodeficiency virus (HIV), hepatitis C or hepatitis B. Seventy-five per cent of hepatitis C or HIV positive men and women are in their reproductive years, and these couples look to assisted reproductive techniques for risk reduction in conceiving a pregnancy. In many cases, only one partner is infected. Legal and ethical questions about treatment of infectious patients aside, the question most asked by clinical embryologists and andrologists is: "What are the laboratory protocols for working with gametes and embryos from patients with infectious disease?" The serostatus of each patient is the key that informs appropriate treatments. This guidance document describes protocols for handling gametes from seroconcordant and serodiscordant couples with infectious disease. With minor modifications, infectious patients with stable disease status and undetectable or low viral load can be accommodated in the IVF laboratory.