The role of Chlamydia trachomatis infection in male infertility

Are sexually transmitted infections associated with male infertility? A systematic review and in-depth evaluation of the evidence and mechanisms of action of 11 pathogens

Purpose

To systematically review the evidence on the association between sexually transmitted infections (STIs) and male infertility. We sought to answer two questions: Are STIs significantly associated with detrimental changes in semen parameters?; and, is the prevalence of STIs significantly higher in infertile than fertile men?

Materials and methods

PubMed, Scopus and Google Scholar databases were searched (inceptionMarch 2023) following the PRISMA guidelines. Identified original studies in English on the association between STIs and male infertility were included. Data was tabulated/described by pathogen, mechanisms of action, number of studies and their level of evidence.

Results

Seventy out of 903 originally retrieved articles were included in this review. For the detrimental changes in semen parameters (first question), the evidence seems equivocal based on the nearly equal number of studies and similar levels of evidence. The only exception was for Ureaplasma, where the number of studies and levels of evidence supported an association with male infertility. Pertaining to a significantly higher prevalence of STI among infertile compared to fertile men (second question), evidence was insufficient to support/deny a significant association. The two exceptions were Ureaplasma and Mycoplasma, where the number of studies and evidence levels were in favour of an association with male infertility.

Conclusions

Generally, the relationship between STIs and male infertility remains to be uncovered. Our appraisal of the overall state of this relationship shows that the evidence base leaves much to be desired. The exceptions are Ureaplasma and Mycoplasma, where the evidence convincingly suggests their associations with infertility in men.

Antichlamydia antibodies and sperm quality among male partners of infertile couples ins Nigeria

Background

The impact of Chlamydia trachomatis on semen quality has been studied with varied results.

Aim

To determine the prevalence of antichlamydial antibodies and their relationship with sperm quality among male partners of infertile couples in Enugu, South-East Nigeria.

Materials and Methods

It was a cross-sectional study of infertile male partners of couples attending infertility clinics at the University of Nigeria Teaching Hospital (UNTH) Ituku-Ozalla, Enugu, Nigeria. Their sera were assayed for antichlamydial antibodies, and semen analysis and culture were done for each participant.

Results

Two hundred and eighty-two (282) male partners of infertile couples were studied. Infertility was commoner among participants aged 40 years or more (45.1%) and was mainly of the "primary type" (62.1%). Antichlamydia antibody was detected in 156 (55.3%) participants and was significantly associated with sperm quality (P = 002; OR = 2.294; 95% CI = 1.36-3.88). Overall, 81 (28.7%) had abnormal sperm quality. The sperm count, progressive motility, and vitality were significantly lower in participants with abnormal sperm quality than those with normal sperm quality (P < 0.001) while morphology, volume, and liquefaction time did not differ significantly (P > 0.05). Staphylococcus aureus was the predominant organism isolated from culture (122/282, 43.3%) while Streptococcus species were the least (4/262, 1.4%). There was significantly more Staphylococcus aureus isolated from the semen of participants that were seropositive to antichlamydial antibodies than those that were seronegative (80/156, 51.3% vs. 42/126, 33.3%; OR = 2.105; 95% CI = 1.30-3.42; P = 0.003).

Conclusion

The prevalence of antichlamydial antibodies among male partners of infertile couples in Enugu, Nigeria is high and there is a significant association with sperm quality, sperm count, and bacterial isolates in seminal culture. Male partners of infertile couples in Enugu should be screened for antichlamydial antibodies and appropriate treatment offered wherever indicated. There is a need for increased public awareness and advocacy campaigns on the impact of Chlamydia infection on male factor infertility. This primary preventive measure may help in reducing the burden of Chlamydia infection and male factor infertility.

Chlamydia-related knowledge, opinion to opportunistic testing, and practices of providers among different sexually transmitted infections related departments in hospitals in Shenzhen city, China

BACKGROUND

Chlamydia trachomatis (CT) infection could lead to seriously adverse outcomes if left untreated. This study aimed to determine CT-related knowledge, opinion to testing, and practices of providers among different sexually transmitted infections (STI) related departments in hospitals in Shenzhen city, China, and also to explore the differences in these responses.

MATERIALS AND METHODS

From 1st April 2018 to 15th April 2018, a cross-sectional study was conducted in Shenzhen and 64 of 66 hospitals agreed to participate in this study. In the hospital sites, all the providers from the department of obstetrics and gynecology, department of dermatology and venereology, department of urology, and anorectal surgical department were recruited. A structured paper-based questionnaire was used to obtain data on CT-related information.

RESULTS

A total of 355 providers from 64 hospitals participated in the current study. Compared to providers from the department of dermatology and venereology, those from the department of obstetrics and gynecology (OR = 0.31, 95% CI 0.16-0.62), department of urology (OR = 0.32, 95% CI 0.16-0.65), and anorectal surgical department (OR = 0.25, 95% CI 0.09-0.71) were less likely to identify that "Be in a long-term mutually monogamous relationship with a partner who has been tested and has negative STI test results." is an appropriate way for a sexually active person to reduce risk of getting CT. Also, those from the department of obstetrics and gynecology (OR = 0.45, 95% CI 0.23-0.87) were less likely to identify that "Use latex condoms the right way every time you have sex" is another appropriate way. A high proportion of providers agreed that all sexually active patients attending to their department should be screened regularly (77.1%), and they are willing to offer opportunistic CT screening (96.0%). Only 11.4% of respondents correctly identified that the appropriate time frame of the CT retesting is three months.

CONCLUSIONS

Providers among STI-related departments in hospitals showed a very high willingness to offer opportunistic CT screening. However, this study showed important gaps in providers' knowledge and practices in China, targeted training in CT-related knowledge and practice is urgently needed.

AAUS guideline for chlamydial urethritis

Urogenital chlamydial infection is the most common sexually transmitted infection. Many cases of chlamydial infection are reported worldwide every year. Genital chlamydial infection in women can also cause obstetric issues, including infertility and miscarriage. For that purpose, appropriate care should be conducted with the latest knowledge. Only few guidelines come from Asian countries. The Asian Association of Urinary Tract Infection and Sexually Transmitted Infection (AAUS) belonging to the Urological Association of Asia (UAA) had developed the guidelines regarding chlamydial urethritis. We have collected the feedback and updated the guidelines which is now submitted for consideration of publication. In addition to the levels of evidence, the recommendation grades were defined using the modified GRADE methodology. Herein, we present the new edition of the UAA-AAUS guidelines for chlamydial urethritis.

Pathogenesis of Autoimmune Male Infertility: Juxtacrine, Paracrine, and Endocrine Dysregulation

According to global data, there is a male reproductive potential decrease. Pathogenesis of male infertility is often associated with autoimmunity towards sperm antigens essential for fertilization. Antisperm autoantibodies (ASAs) have immobilizing and cytotoxic properties, impairing spermatogenesis, causing sperm agglutination, altering spermatozoa motility and acrosomal reaction, and thus preventing ovum fertilization. Infertility diagnosis requires a mandatory check for the ASAs. The concept of the blood–testis barrier is currently re-formulated, with an emphasis on informational paracrine and juxtacrine effects, rather than simple anatomical separation. The etiology of male infertility includes both autoimmune and non-autoimmune diseases but equally develops through autoimmune links of pathogenesis. Varicocele commonly leads to infertility due to testicular ischemic damage, venous stasis, local hyperthermia, and hypoandrogenism. However, varicocelectomy can alter the blood–testis barrier, facilitating ASAs production as well. There are contradictory data on the role of ASAs in the pathogenesis of varicocele-related infertility. Infection and inflammation both promote ASAs production due to “danger concept” mechanisms and because of antigen mimicry. Systemic pro-autoimmune influences like hyperprolactinemia, hypoandrogenism, and hypothyroidism also facilitate ASAs production. The diagnostic value of various ASAs has not yet been clearly attributed, and their cut-levels have not been determined in sera nor in ejaculate. The assessment of the autoimmunity role in the pathogenesis of male infertility is ambiguous, so the purpose of this review is to show the effects of ASAs on the pathogenesis of male infertility.

Chronic testicular Chlamydia muridarum infection impairs mouse fertility and offspring development†

With approximately 131 million new genital tract infections occurring each year, Chlamydia is the most common sexually transmitted bacterial pathogen worldwide. Male and female infections occur at similar rates and both cause serious pathological sequelae. Despite this, the impact of chlamydial infection on male fertility has long been debated, and the effects of paternal chlamydial infection on offspring development are unknown. Using a male mouse chronic infection model, we show that chlamydial infection persists in the testes, adversely affecting the testicular environment. Infection increased leukocyte infiltration, disrupted the blood:testis barrier and reduced spermiogenic cell numbers and seminiferous tubule volume. Sperm from infected mice had decreased motility, increased abnormal morphology, decreased zona-binding capacity, and increased DNA damage. Serum anti-sperm antibodies were also increased. When both acutely and chronically infected male mice were bred with healthy female mice, 16.7% of pups displayed developmental abnormalities. Female offspring of chronically infected sires had smaller reproductive tracts than offspring of noninfected sires. The male pups of infected sires displayed delayed testicular development, with abnormalities in sperm vitality, motility, and sperm-oocyte binding evident at sexual maturity. These data suggest that chronic testicular Chlamydia infection can contribute to male infertility, which may have an intergenerational impact on sperm quality.

[Update of Chlamydia trachomatis infection]

Chlamydia trachomatis (CT) is the most common sexually transmitted bacterial infection worldwide. It is asymptomatic in most cases and mainly affects young women, with potential long term sequelae (pelvic inflammatory disease, tubal infertility, obstetric complications). The impact on male fertility is controversial. Screening methods as well as antibiotics use have recently been reassessed due to resistance phenomena and the negative effect on the urogenital microbiota. Positive CT serology may be indicative of tuboperitoneal pathology, which may not be noticed on hysterosalpingography. New research on single-nucleotide polymorphisms (SNPs) aims to establish a patient profile at higher risk of infectious tubal damage due to CT. CT seropositivity is also associated with decreased spontaneous pregnancy rates and is a predictive factor for obstetrical complications.

HIV, HPV and Chlamydia trachomatis: impacts on male fertility

Sexually transmitted diseases (STDs) are pathologies that have viruses, bacteria, protozoa and fungi as infectious agents, affecting millions of people worldwide and causing physical and psychological consequences for the carrier. Some of these infections such as HIV, HPV and Chlamydia trachomatis may present an asymptomatic phase, making the diagnosis difficult, which is often only performed when the couple looks for infertility treatment after not achieving spontaneous pregnancy. Infertility affects 15% of couples, 50% of cases are male-related, and it is estimated that STDs, which interfere with the physiology of the male reproductive system and may impair semen in parameters such as motility, concentration, morphology and number, cause 15% of male infertility cases. Since STDs treatments are increasing the expectation and quality of life of infected patients, discussing issues such as sexuality and reproduction is of great importance in clarifying unknown facts. This paper aims to discuss how the infectious processes associated with HIV, HPV and Chlamydia trachomatis can interfere with semen quality causing male infertility without apparent cause.

Bacterial infection of the male reproductive system causing infertility

Bacterial infections play a disruptive and hidden role in male reproductive failure. Different kinds of bacteria are often able to interfere with reproductive function in both sexes and lead to infertility. In this study, to further evaluate the role of bacterial infections in male reproduction we provided an extensive overview of so far researches investigating the effects of bacterial infections on male fertility. We searched Medline, PubMed, Scopus and Google scholar databases to identify the potentially relevant studies on bacterial infections and their implications in male infertility. All the bacteria included in this article have negative effects on the male reproductive function; however, there is ample evidence to blame bacteria such as Escherichia coli, Chlamydia trachomatis, Ureaplasma, Mycoplasma and Staphylococcus aureus for reduced fertility and deterioration of sperm parameters. More studies are needed to clarify the molecular mechanisms by which different bacteria exert their detrimental effects on male reproductive system. Getting more insight into probable mechanisms, would significantly facilitate the production of new, advanced, and effective remedies in the future. In view of all evidence, we strongly suggest increasing awareness among people and considering screening programs for patients seeking fertility both to avoid transmission and to improve fertility outcomes among them.

Time series analysis and forecasting of chlamydia trachomatis incidence using surveillance data from 2008 to 2019 in Shenzhen, China

Chlamydia trachomatis (CT) infection has been a major public health threat globally. Monitoring and prediction of CT epidemic status and trends are important for programme planning, allocating resources and assessing impact; however, such activities are limited in China. In this study, we aimed to apply a seasonal autoregressive integrated moving average (SARIMA) model to predict the incidence of CT infection in Shenzhen city, China. The monthly incidence of CT between January 2008 and June 2019 in Shenzhen was used to fit and validate the SARIMA model. A seasonal fluctuation and a slightly increasing pattern of a long-term trend were revealed in the time series of CT incidence. The monthly CT incidence ranged from 4.80/100 000 to 21.56/100 000. The mean absolute percentage error value of the optimal model was 8.08%. The SARIMA model could be applied to effectively predict the short-term CT incidence in Shenzhen and provide support for the development of interventions for disease control and prevention.

Waddlia chondrophila and Male Infertility

Waddlia chondrophila, a Chlamydia-like bacterium, has been previously associated with adverse pregnancy outcomes. Analogously to Chlamydia trachomatis, W. chondrophila also negatively impacts human semen and may be a source of impaired male fertility. In this study, we analyzed W. chondrophila seroprevalence in a population of male patients of infertile couples and the impact of past exposition to this bacterium on semen parameters. Our results show a surprisingly high seroprevalence of W. chondrophila, which contrasts with a previous study focusing on a population of healthy men. Nevertheless, we did not observe any significant association between positive serology and abnormal sperm parameters. This may suggest that a negative impact on semen is observed only during an ongoing infection. Alternatively, W. chondrophila may have an immune impact on male fertility, as previously postulated for women with adverse pregnancy outcomes.

Anatomical site prevalence and genotypes of Chlamydia trachomatis infections among men who have sex with men: a multi-site study in China

Background

Chlamydia trachomatis (CT) infection is one of the most pervasive sexually transmitted infections and has high prevalence in urogenital and extra-urogenital sites among men who have sex with men (MSM). This study investigated anatomical site-specific prevalence and genotypes of CT among MSM recruited from three geographic areas in China.

Methods

We collected urine specimens and anorectal, pharyngeal swab specimens from 379 MSM. CT infection was identified using polymerase chain reaction and CT genotyping was determined by sequences of the ompA gene.

Results

The results indicated that the overall prevalence of CT infection was 18.2% (95% confidence intervals [CIs], 13.9–22.5%) and significantly different between the cities (p = 0.048). The infection was most common at the anorectal site (15.6, 95%CIs 11.6–19.5%) followed by urethral (3.2, 95%CIs 1.4–5.0%) and oropharyngeal sites (1.6, 95%CIs 0.3–2.9%). Genotypes D and G were the most common CT strains in this population but genotype D was significantly predominated in Nanjing while genotype G was in Wuhan. No genotype related to lymphogranuloma venereum was found. CT infection was significantly related to the infection of Neisseria gonorrhoeae (adjusted odds ratio [aOR] 14.27, 95%CIs 6.02–33.83, p < 0.001) and age. Men older than 40 years old were less likely to have a CT infection as compared to men under 30 years old (aOR 0.37, 95% CIs 0.15–0.93, p = 0.03).

Conclusion

The high CT infection prevalence, particularly in the anorectal site, among MSM suggests the necessity to development an integrated CT screening and treatment program specifically focusing on this high-risk population. Surveillance of CT infections should be improved by including both infection and genotype based surveys into the current surveillance programs in China.

[Sexually transmitted infections and male fertility]

BACKGROUND

Sexually transmitted infections (STI) are common worldwide and can cause impairment of fertility. In women pelvic inflammatory disease with subsequent tubal sterility is well-documented but the influence of STI on male fertility is still controversely discussed OBJECTIVE: The effects of various bacterial and viral STI on male fertility are discussed.

MATERIAL AND METHODS

An evaluation of the international literature up to 30 April 2018 was carried out including studies on larger collectives from the Asiatic region.

RESULTS

There is still an inconsistent picture of the influence of various bacterial and viral STI on male fertility. Direct or indirect evidence of the impact of a pathogen alone on the quality of ejaculates could not be clearly demonstrated; however, there are indications of a negative effect by Mycoplasma and Ureaplasma species in large Asiatic collectives. The transmission of viral pathogens, such as human papillomavirus (HPV), herpes simplex virus (HSV) and hepatitis B virus (HBV) possible impairs the success of assisted reproductive techniques. In contrast, manifest inflammatory processes of the male genital tract caused by STI (in particular Chlamydia and gonococci) or human immunodeficiency virus (HIV) infections often result in impairment of sperm qualtity.

CONCLUSION

In cases of male fertility disorders a microbiological clarification is recommended. Further studies on the effect of STI on male fertility in larger collectives are necessary, particularly for Caucasian populations. The utilization of existing preventive measures, such as screening for Chlamydia in young women and HPV vaccination also for young males, should be intensively promoted.

Waddlia chondrophila, a Chlamydia-related bacterium, has a negative impact on human spermatozoa

STUDY QUESTION

What is the impact of Waddlia chondrophila, an emerging Chlamydia-related bacterium associated with miscarriage, on human spermatozoa?

SUMMARY ANSWER

W. chondrophila had a negative impact on human spermatozoa (decrease in viability and mitochondrial membrane potential) and was not entirely removed from infected samples by density gradient centrifugation.

WHAT IS KNOWN ALREADY

Bacterial infection or colonization might have a deleterious effect on male fertility. Waddlia chondrophila was previously associated with miscarriage, but its impact on male reproductive function has never been studied.

STUDY DESIGN SIZE, DURATION

An in vitro model of human spermatozoa infection was used to assess the effects of W. chondrophila infection. Controls included Chlamydia trachomatis serovar D and latex beads with similar size to bacteria.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Purified motile spermatozoa were infected with W. chondrophila (multiplicity of infection of 1). Immunohistochemistry combined with confocal microscopy was used to evaluate how bacteria interact with spermatozoa. The impact on physiology was assessed by monitoring cell viability, mitochondrial membrane potential and DNA fragmentation.

MAIN RESULTS AND THE ROLE OF CHANCE

Using super-resolution confocal microscopy, bacteria were localized on spermatozoa surface, as well as inside the cytoplasm. Compared to controls, W. chondrophila caused a 20% increase in mortality over 72 h of incubation (P < 0.05). Moreover, higher bacterial loads significantly reduced mitochondrial membrane potential. Bacteria present on spermatozoa surface were able to further infect a cell-monolayer, indicating that sperm might vector bacteria during sexual intercourse.

LIMITATIONS REASONS FOR CAUTION

The main limitation of the study is the use of an in vitro model of infection, which might be too simplistic compared to an actual infection. An animal model of infection should be developed to better evaluate the in vivo impact of W. chondrophila.

WIDER IMPLICATIONS OF THE FINDINGS

Intracellular bacteria, including C. trachomatis, Mycoplasma spp. and Ureaplasma spp., are associated with male infertility. Waddlia chondrophila might represent yet another member of this group, highlighting the need for more rigorous microbiological analysis during investigations for male infertility.

STUDY FUNDING/COMPETING INTEREST(S)

This work has been funded by the Department of Obstetrics and Gynecology, Lausanne University Hospital, Switzerland, and by the Swiss National Science Foundation (Grant nos. 310030-156169/1, 320030-169853/1 and 320030-169853/2 attributed to D.B.). D.B. is also supported by the 'Fondation Leenaards' through the 'Bourse pour la relève académique', by the 'Fondation Divesa' and by the 'Loterie Romande'. No conflicts of interest to declare.

Chlamydia pecorum Infection in the Male Reproductive System of Koalas ( Phascolarctos cinereus)

Chlamydiosis is the most documented and serious disease of koalas, characterized by ocular, urinary, and reproductive lesions. Since little attention has been paid to the pathological effects of this infection in the male reproductive system, we aimed to determine the incidence and severity of reproductive pathology associated with chlamydial infection in male koalas submitted to koala hospitals in southeast Queensland. The entire reproductive tract from 62 sexually mature male koalas not suitable for rehabilitation was evaluated and 677 tissue samples were collected for histology, immunohistochemistry (IHC), and real-time polymerase chain reaction (qPCR). Lymphoplasmacytic inflammation was observed in 178 of 677 (26.3%) tissue samples from the upper and lower reproductive tract, mainly in the prostatic, penile, and membranous urethra. IHC was positive for the chlamydial antigen in 19 of 451 normal samples (4.2%) and 46 of 178 samples with inflammation (25.8%), located within the cytoplasm of epithelial cells of the epididymis, vas deferens, prostate, bulbourethral glands, and the prostatic membranous and penile urethra. Chlamydia pecorum was detected via qPCR in 319 of 451 normal samples (70.7%) and 159 of 178 samples with inflammation (89.3%), with the highest incidence in the penile urethra, prostate, membranous urethra, and bulbourethral glands. This study suggests that Chlamydia infection in the male reproductive tract is more widespread than originally thought. Furthermore, the male reproductive tract might be a reservoir for persistent chlamydial infections in koalas, with important implications for prophylactic strategies and epidemiology.

Reactive oxygen species and male reproductive hormones

Reports of the increasing incidence of male infertility paired with decreasing semen quality have triggered studies on the effects of lifestyle and environmental factors on the male reproductive potential. There are numerous exogenous and endogenous factors that are able to induce excessive production of reactive oxygen species (ROS) beyond that of cellular antioxidant capacity, thus causing oxidative stress. In turn, oxidative stress negatively affects male reproductive functions and may induce infertility either directly or indirectly by affecting the hypothalamus-pituitary-gonadal (HPG) axis and/or disrupting its crosstalk with other hormonal axes. This review discusses the important exogenous and endogenous factors leading to the generation of ROS in different parts of the male reproductive tract. It also highlights the negative impact of oxidative stress on the regulation and cross-talk between the reproductive hormones. It further describes the mechanism of ROS-induced derangement of male reproductive hormonal profiles that could ultimately lead to male infertility. An understanding of the disruptive effects of ROS on male reproductive hormones would encourage further investigations directed towards the prevention of ROS-mediated hormonal imbalances, which in turn could help in the management of male infertility.

The impact of Chlamydia trachomatis infection on sperm parameters and male fertility: A comprehensive study

Chlamydia trachomatis (CT), an obligate intracellular bacterium, requires living cells to replicate. Half of men infected with CT are asymptomatic. CT infection can persist for up to four years within couples and affect their fertility. Chlamydia infection in men acts as a reservoir for transmission to women and can cause urinary tract inflammation, sperm DNA damage, and acute epididymitis. Semen samples from 1080 subfertile patients with normal and abnormal spermograms were examined to detect the presence of CT. An ELISA test was used to detect the presence of anti-CT IgA in these patients' seminal plasma. CT infection was also confirmed by molecular investigation using specific primers. In order to evaluate the effect of CT infections on the DNA Fragmentation Index (DFI), 40 CT-infected cases and 20 CT-negative controls were analyzed by a Sperm Chromatin Structure Assay using flow cytometry. Among 1080 patients with poor sperm parameters, 155 (14.3%) patients were diagnosed with CT, 11% among those with semen abnormalities and 26% among those without semen abnormalities patients. The DFI was statistically higher in cases than in controls (p < 0.05). Given the prevalence of infection and also the high frequency of asymptomatic CT infection among infertile individuals with poor sperm parameters, screening for infection in these patients is essential in order to avoid adverse sequelae. We propose that the higher rate of DFI in CT-infected infertile men might be an underlying cause of their infertility and this warrants greater attention.

Chlamydia trachomatis neither exerts deleterious effects on spermatozoa nor impairs male fertility

Chlamydia trachomatis is the most prevalent sexually transmitted bacterial infection. However, whether Chlamydia trachomatis has a negative impact on sperm quality and male fertility is still controversial. Herein, we report the effects on sperm quality of the in vitro exposure of spermatozoa to Chlamydia trachomatis, and also the effects of male genital infection on male fertility using an animal model. Human and mouse sperm were obtained from healthy donors and cauda epididimys from C57BL/6 mice, respectively. Highly motile human or mouse spermatozoa were in vitro exposed to C. trachomatis (serovar E or LGV) or C. muridarum, respectively. Then, sperm quality parameters were analyzed. Moreover, male fertility of Chlamydia muridarum infected male C57BL/6 mice was assessed. Human or murine sperm in vitro exposed to increasing bacterial concentrations or soluble factors from C. trachomatis or C. muridarum, respectively, did not show differences in sperm motility and viability, apoptosis, mitochondrial membrane potential, DNA fragmentation, ROS production and lipid peroxidation levels, when compared with control sperm (p > 0.05). Moreover, no differences in fertility parameters (potency, fecundity, fertility index, pre- and post-implantation loss) were observed between control and infected males. In conclusion, our results indicate that Chlamydia spp. neither directly exerts deleterious effects on spermatozoa nor impairs male fertility.

Background review for the '2015 European guideline on the management of Chlamydia trachomatis infections'

SummaryChlamydia trachomatis infections are major public health concerns globally. Of particular grave concern is that the majority of persons with anogenital Chlamydia trachomatis infections are asymptomatic and accordingly not aware of their infection, and this silent infection can subsequently result in severe reproductive tract complications and sequelae. The current review paper provides all background, evidence base and discussions for the 2015 European guideline on the management of Chlamydia trachomatis infections (Lanjouw E, et al. Int J STD AIDS 2015). Comprehensive information and recommendations are included regarding the diagnosis, treatment and prevention of anogenital, pharyngeal and conjunctival Chlamydia trachomatis infections in European countries. However, Chlamydia trachomatis also causes the eye infection trachoma, which is not a sexually transmitted infection. The 2015 European Chlamydia trachomatis guideline provides up-to-date guidance regarding broader indications for testing and treatment of Chlamydia trachomatis infections; clearer recommendation of using validated nucleic acid amplification tests only for diagnosis; advice on (repeated) Chlamydia trachomatis testing; recommendation of increased testing to reduce the incidence of pelvic inflammatory disease and prevent exposure to infection and recommendations to identify, verify and report Chlamydia trachomatis variants. Improvement of access to testing, test performance, diagnostics, antimicrobial treatment and follow-up of Chlamydia trachomatis patients are crucial to control its spread.

2015 European guideline on the management of Chlamydia trachomatis infections

Chlamydia trachomatis infections, which most frequently are asymptomatic, are major public health concerns globally. The 2015 European C. trachomatis guideline provides: up-to-date guidance regarding broader indications for testing and treatment of C. trachomatis infections; a clearer recommendation of using exclusively-validated nucleic acid amplification tests for diagnosis; advice on (repeated) C. trachomatis testing; the recommendation of increased testing to reduce the incidence of pelvic inflammatory disease and prevent exposure to infection; and recommendations to identify, verify and report C. trachomatis variants. Improvement of access to testing, test performance, diagnostics, antimicrobial treatment and follow-up of C. trachomatis patients are crucial to control its spread. For detailed background, evidence base and discussions, see the background review for the present 2015 European guideline on the management of Chlamydia trachomatis infections (Lanjouw E, et al. Int J STD AIDS. 2015).

2015 UK national guideline for the management of infection with Chlamydia trachomatis

This guideline offers recommendations on the diagnostic tests, treatment regimens and health promotion principles needed for the effective management of Chlamydia trachomatis genital infection. It covers the management of the initial presentation, as well the prevention of transmission and future infection. The guideline is aimed at individuals aged 16 years and older presenting to healthcare professionals working in departments offering Level 3 care in sexually transmitted infections management within the UK. However, the principles of the recommendations should be adopted across all levels, using local care pathways where appropriate.

Chlamydia muridarum infection-induced destruction of male germ cells and sertoli cells is partially prevented by Chlamydia major outer membrane protein-specific immune CD4 cells

Chlamydia trachomatis infections are increasingly prevalent worldwide. Male chlamydial infections are associated with urethritis, epididymitis, and orchitis; however, the role of Chlamydia in prostatitis and male factor infertility remains controversial. Using a model of Chlamydia muridarum infection in male C57BL/6 mice, we investigated the effects of chlamydial infection on spermatogenesis and determined the potential of immune T cells to prevent infection-induced outcomes. Antigen-specific CD4 T cells significantly reduced the infectious burden in the penile urethra, epididymis, and vas deferens. Infection disrupted seminiferous tubules, causing loss of germ cells at 4 and 8 wk after infection, with the most severely affected tubules containing only Sertoli cells. Increased mitotic proliferation, DNA repair, and apoptosis in spermatogonial cells and damaged germ cells were evident in atrophic tubules. Activated caspase 3 (casp3) staining revealed increased (6-fold) numbers of Sertoli cells with abnormal morphology that were casp3 positive in tubules of infected mice, indicating increased levels of apoptosis. Sperm count and motility were both decreased in infected mice, and there was a significant decrease in morphologically normal spermatozoa. Assessment of the spermatogonial stem cell population revealed a decrease in promyelocytic leukemia zinc finger (PLZF)-positive cells in the seminiferous tubules. Interestingly, adoptive transfer of antigen-specific CD4 cells, particularly T-helper 2-like cells, prior to infection prevented these effects in spermatogenesis and Sertoli cells. These data suggest that chlamydial infection adversely affects spermatogenesis and male fertility, and that vaccination can potentially prevent the spread of infection and these adverse outcomes.

Male infertility: a public health issue caused by sexually transmitted pathogens

Sexually transmitted diseases (STDs) are caused by several pathogens, including bacteria, viruses and protozoa, and can induce male infertility through multiple pathophysiological mechanisms. Additionally, horizontal transmission of STD pathogens to sexual partners or vertical transmission to fetuses and neonates is possible. Chlamydia trachomatis, Ureaplasma spp., human papillomavirus, hepatitis B and hepatitis C viruses, HIV-1 and human cytomegalovirus have all been detected in semen from symptomatic and asymptomatic men with testicular, accessory gland and urethral infections. These pathogens are associated with poor sperm quality and decreased sperm concentration and motility. However, the effects of these STD agents on semen quality are unclear, as are the effects of herpes simplex virus type 1 and type 2, Neisseria gonorrhoeae, Mycoplasma spp., Treponema pallidum and Trichomonas vaginalis, because few studies have evaluated the influence of these pathogens on male infertility. Chronic or inadequately treated infections seem to be more relevant to infertility than acute infections are, although in many cases the exact aetiological agents remain unknown.

Screening for Chlamydia infection in a sexually transmitted infection clinic: a missed opportunity?

OBJECTIVES

Chlamydia trachomatis (CT) infection is the most common sexually transmitted infection (STI) reported in Europe. We aim to evaluate the overall prevalence of CT infection and the rate of asymptomatic infection in an STI clinic over a 5-year period. We will also discuss screening strategies with reference to attendees diagnosed with an STI and their sexual partners, and attendees with a non-infectious genital dermatosis.

METHODS

Clinical and laboratory data for all attendees at a university hospital STI clinic over a 5-year period were reviewed. Diagnosis of CT infection was made upon polymerase chain reaction (PCR) performed in first-void urine.

RESULTS

The overall prevalence of CT infection was 4.0% (53/1310); the rate of asymptomatic infection was 84.9% (45/53). The prevalence of CT infection among attendees with an STI diagnosis and their sexual partners was 5.2% (50/963), whereas that among attendees with a non-infectious genital dermatosis was 0.9% (3/347; P < 0.001). Infected attendees were younger than attendees without CT infection (median age: 31 years vs. 40 years; P < 0.001). In 39.5% (17/43) of CT-infected attendees, it was possible to notify a sexual partner; CT infection was subsequently diagnosed in 58.8% (10/17) of partners.

CONCLUSIONS

Asymptomatic CT infection had a representative frequency, which was more pronounced among young attendees with an STI diagnosis and their sexual partners, to whom screening should be offered. Issues of age limits for screening and whether screening should be directed to males in non-STI clinic settings should be carefully assessed.

Chlamydia trachomatis infection of the male genital tract: an update

Chlamydia trachomatis (CT) is the most prevalent cause of sexually transmitted diseases. Although the prevalence of chlamydial infection is similar in men and women, current research and screening are still focused on women, who develop the most severe complications, leaving the study of male genital tract (MGT) infection underrated. Herein, we reviewed the literature on genital CT infection with special focus on the MGT. Data indicate that CT certainly infects different parts of the MGT such as the urethra, seminal vesicles, prostate, epididymis and testis. However, whether or not CT infection has detrimental effects on male fertility is still controversial. The most important features of CT infection are its chronic nature and the presence of a mild inflammation that remains subclinical in most individuals. Chlamydia antigens and pathogen recognition receptors (PRR), expressed on epithelial cells and immune cells from the MGT, have been studied in the last years. Toll-like receptor (TLR) expression has been observed in the testis, epididymis, prostate and vas deferens. It has been demonstrated that recognition of chlamydial antigens is associated with TLR2, TLR4, and possibly, other PRRs. CT recognition by PRRs induces a local production of cytokines/chemokines, which, in turn, provoke chronic inflammation that might evolve in the onset of an autoimmune process in genetically susceptible individuals. Understanding local immune response along the MGT, as well as the crosstalk between resident leukocytes, epithelial, and stromal cells, would be crucial in inducing a protective immunity, thus adding to the design of new therapeutic approaches to a Chlamydia vaccine.

Chlamydia trachomatis in Tasmania 2001-2007: rising notification trends

OBJECTIVES

To investigate trends in notification rates of Chlamydia trachomatis in Tasmania, Australia, by population sub-groups, from 1 January 2001 to 31 December 2007.

METHODS

An enhanced surveillance dataset was used to supplement case notifications. Rates based on age group were analysed by sex, geographic region, indigenous status, sexual exposure, reason for testing and healthcare provider.

RESULTS

In all age groups, the notification rate increased steeply. The highest rates were seen in the ages 15-24 years; this age group represented 15% of the population but accounted for 74% of the chlamydial notifications. The increased rates in females aged 15-24 years and males 15-19 years in Tasmania were larger than the increases observed nationally. Rates were consistently higher in urban areas. Females were more likely to have been tested as a result of screening, and males were more likely to have been tested when presenting with symptoms or as a result of contact tracing. The majority of cases reported sexual exposure with opposite sex partners only.

CONCLUSIONS

This study highlights the increasing significance of chlamydial infection as a public health issue, the gender differences in health-seeking behaviour, and the discrepancies in testing patterns. These findings will assist with the design of health promotion programs.

Increasing young adults' condom use intentions and behaviour through changing chlamydia risk and coping appraisals: study protocol for a cluster randomised controlled trial of efficacy

BACKGROUND

Chlamydia is the most commonly diagnosed sexually transmitted infection (STI) in England and has serious public health consequences. Young people carry a disproportionate burden of infection. A number of social cognition models identify risk appraisal as a primary motivator of behaviour suggesting that changing risk appraisals for STIs may be an effective strategy in motivating protective behaviour. Meta-analytic evidence indicates that the relationship between risk appraisal and health behaviour is small, but studies examining this relationship have been criticised for their many conceptual and methodological weaknesses. The effect of risk appraisal on health behaviour may therefore be of larger size. The proposed study aims to examine the efficacy of an intervention to increase condom use intentions and behaviour amongst young people through changing chlamydia risk and coping appraisals. Coping appraisal is targeted to avoid the intervention being counterproductive amongst recipients who do not feel able to perform the behaviour required to reduce the threat. An experimental design with follow-up, a conditional measure of risk appraisal, and analysis which controls for past behaviour, enable the relationship between risk appraisal and protective behaviour to be accurately assessed.

METHODS/DESIGN

The proposed study is a two-arm cluster randomised controlled trial using a waiting-list control design to test the efficacy of the intervention compared to a control group. Participants will be school pupils aged 13-16 years old recruited from approximately ten secondary schools. Schools will be randomised into each arm. Participants will receive their usual teaching on STIs but those in the intervention condition will additionally receive a single-session sex education lesson on chlamydia. Measures will be taken at baseline, post-intervention and at follow-up three months later. The primary outcome measure is intention to use condoms with casual sexual partners.

DISCUSSION

As far as the authors are aware, this is the first controlled trial testing the efficacy of an intervention to increase condom use intentions and behaviour through changing chlamydia risk appraisals. It is one of few experimental studies to accurately test the relationship between risk appraisal and precautionary sexual behaviour using a conditional measure of risk appraisal and controlling for past behaviour.

Sexually transmitted infections and sexual function in relation to male fertility

Infertility affects about 8% to 12% of couples, with male infertility being responsible for about 30% of cases. Sexually transmitted infections (STIs) are known to cause complications of pregnancy and are associated with tubal infertility in females, but the association with male fertility is still controversial. The prevalence of curable STIs has risen to an estimated 448 million a year with the number of people living with human immunodeficiency virus (HIV) at 34 million. This review looks at the evidence available to date, regarding the effect of STIs and male accessory gland infections on markers of male fertility and the evidence that STIs negatively affect sexual functioning, thus adversely affecting the ability to conceive. The review will also cover new developments in the use of medications and fertility treatments as an aid to conception in couples serodiscordant for HIV.

Rapid screening for Chlamydia trachomatis infection by detecting α-mannosidase activity in urogenital tract specimens

BACKGROUND

Chlamydia trachomatis may cause multiple different urogenital tract disorders, but current non-culture assays for rapid screening of C. trachomatis typically use immunochromatography-based methods. We established another new rapid non-culture method for detection of C. trachomatis based on the measurement of α-mannosidase enzymatic activity in urogenital tract specimens.

METHOD

To evaluate the performance of this method, α-mannosidase activities of C. trachomatis serotype D strain 、 and 29 standard strains related to clinical urogenital pathogens were investigated. Furthermore, 553 urogenital tract specimens were used for clinical assays via cell culture method and ligase chain reaction method (LCR), adopting an expanded gold standard.

RESULTS

Only C. trachomatis was positive for α-mannosidase activity among different types of microbes tested in the research. When prostate fluid specimens, which have some interfering activity, were excluded, the sensitivity and specificity of the enzymatic method were 91.8% (78/85) and 98.3% (409/416), respectively. There were no significant differences (P > 0.05).

CONCLUSIONS

These results showed that α-mannosidase activity could be utilised as a screening marker of C. trachomatis infection.

Current concepts of the epidemiology, clinical picture, diagnostics and therapy of non-complicated and complicated forms of the urogenital chlamydia infection in men

The authors present the results of recent studies of the epidemiology and immunopathogenesis of non-complicated and complicated forms of the urogenital chlamydia infection in men. They also present the results of a study of clinical features of the chlamydia infection and describe up-to-date diagnostics and treatment methods.

University students' perceptions of environmental risks to infertility

BACKGROUND

Canadian young adults may be at risk of future infertility due to the high incidence of sexually transmissible infections (STIs) in this population. Young adults' perceptions of environmental risks, including contaminants, STIs and lifestyle habits on infertility, have not been examined. We have therefore designed a qualitative study to explore risk perceptions, awareness and knowledge of common environmental risk factors for infertility in a multiethnic sample of young adults.

METHODS

Semistructured interviews were carried out with 40 university undergraduate students (16 men and 24 women) in Ottawa, Canada, followed by qualitative analysis of interview transcripts to identify major themes.

RESULTS

The following broad themes described participants' risk perceptions about infertility and (1) environmental contaminants: knowledge gaps, media reports and negative perception of chemicals; (2) STIs: superficial understanding of their role in infertility, general awareness, associations with sexual behaviours and knowledge gaps; and (3) lifestyle: protective benefits of healthy lifestyle, dose or exposure effects for smoking and alcohol, and knowledge gaps. Students demonstrated a superficial understanding of environmental risks, at times relying on media reports and anecdotal information to support their beliefs.

CONCLUSIONS

This next generation of potential infertility patients exhibits a general understanding of environmental risks to infertility; however, young adults are overly optimistic that healthy lifestyle behaviours will safeguard future fertility. STIs represent the most significant modifiable risk factors for this age group; a message that can be supported by sexual and reproductive health education and promotion with greater emphasis on the long-term outcomes of STIs, including infertility.

Chlamydia trachomatis infections of the female genital tract: state of the art

Chlamydia trachomatis (CT) is the most common bacterial cause of sexually transmitted infections. CT infections are strongly associated with risk-taking behavior. Recommendations for testing have been implemented in many countries. The effectiveness of the screening programs has been questioned since chlamydia rates have increased. However, the complication rates including pelvic inflammatory disease, tubal factor infertility, and tubal pregnancy have been decreasing, which is good news. The complication rates associated with CT infection have clearly been over-estimated. Genetic predisposition and host immune response play important roles in the pathogenesis of long-term complications. CT plays a co-factor role in the development of cervical neoplasia caused by high-risk human papillomavirus (HPV) types. The evidence linking CT and other adverse pregnancy outcomes is weak. The current nucleic acid amplification tests perform well. A new genetic variant of CT was discovered in Sweden but has only rarely been detected elsewhere. Single-dose azithromycin remains effective against CT. Secondary prevention by screening is still the most important intervention to limit the adverse effects of CT on reproductive health.

Antichlamydial antibodies, human fertility, and pregnancy wastage

Genital infections with Chlamydia trachomatis (C. trachomatis) continue to be a worldwide epidemic. Immune response to chlamydia is important to both clearance of the disease and disease pathogenesis. Interindividual responses and current chlamydial control programs will have enormous effects on this disease and its control strategies. Humoral immune response to C. trachomatis occurs in humans and persistent antibody levels appear to be most directly correlated with more severe and longstanding disease and with reinfection. There is a close correlation between the presence of antichlamydial antibodies in females and tubal factor infertility; the closest associations have been found for antibodies against chlamydial heat shock proteins. The latter antibodies have also been shown to be useful among infertile patients with prior ectopic pregnancy, and their presence has been correlated with poor IVF outcomes, including early pregnancy loss. We review the existing literature on chlamydial antibody testing in infertile patients and present an algorithm for such testing in the infertile couple.

How do young adults perceive the risk of chlamydia infection? A qualitative study

OBJECTIVES

This study aimed to improve understanding of how young UK genito-urinary medicine (GUM) patients perceive the risk of chlamydia, and identify implications for health education.

DESIGN

A qualitative methodology was chosen.

METHODS

Semi-structured interviews with 27 respondents aged 16-22 years old were conducted. Data were subjected to thematic analysis.

RESULTS

Respondents made assessments of the perceived seriousness of, and their personal susceptibility to, chlamydia infection. Judgements about seriousness were related to beliefs about the controllability of symptoms and the long-term health consequences of infection. Susceptibility estimates were related to beliefs about the extent to which personal exposure put them in contact with chlamydia, and about the prevalence of infection amongst their peer group. This is consistent with the content of illness risk representations proposed by Cameron (2003). Respondents demonstrated some beliefs, which appeared to influence perceptions of seriousness and susceptibility in unhelpful ways.

CONCLUSIONS

Young people may be underestimating their risk of chlamydia infection due to the presence of unhelpful beliefs. Dialogue between health professionals and patients within GUM clinics, or through consultations as part of the National Chlamydia Screening Programme (NCSP), could provide vehicles to deliver health education to target these. Suggested health education includes highlighting false reassurance provided by treatment beliefs and exposing the fallibility of using overt characteristics to judge the likelihood that a potential sexual partner poses a risk of infection.

2010 European guideline for the management of Chlamydia trachomatis infections

This guideline aims to provide comprehensive information regarding the management of infections caused by Chlamydia trachomatis in European countries. The recommendations contain important information for physicians and laboratory staff working with sexually transmitted infections (STIs) and/or STI-related issues. Individual European countries may be required to make minor national adjustments to this guideline as some of the tests or specific local data may not be accessible, or because of specific laws.

Internet-based screening for sexually transmitted infections to reach nonclinic populations in the community: risk factors for infection in men

BACKGROUND

Internet-based screening for sexually transmitted infections (STIs) has been acceptable to women, and can reach high-risk populations. No prior published data describe internet-based screening for Chlamydia trachomatis, Neisseria gonorrhoeae, and Trichomonas vaginalis in men. We studied whether internet-based screening was acceptable and reached a high-risk population, and what risk factors were associated with STI positivity.

METHODS

The website, www.iwantthekit.org, encouraged men ≥14 years of age to request a home self-sampling kit and a questionnaire on risk factors and acceptability of internet-based screening. Penile swabs and urine samples were tested for C. trachomatis, N. gonorrhoeae, and T. vaginalis using a nucleic acid amplification test. Risk factors and acceptability were examined using chi squared tests and logistic regression.

RESULTS

Of 501 samples received for testing, 106 (21%) were positive for at least one STI, 64 (13%) for chlamydia, 4 (1%) for gonorrhea, and 49 (10%) for trichomonas. In multivariable analyses, age, race, household income, and frequency of condom use were independently associated with infection with at least one STI. Of the total respondents, 34% had a prior STI; 29% reported having a partner with an STI, but only 13% reported always using a condom. Among the men who participated in this study, 77% preferred a self-administered specimen versus attending a clinic, 89% reported that swab use was easy, and 89% reported that they would use internet-based screening again.

CONCLUSIONS

Men who accessed internet-based screening had known risk factors for STIs and had a high prevalence of infection. Internet-based screening was acceptable and could reach these high-risk men who might not otherwise be reached through traditional means.

Chlamydia trachomatis prevalence in unselected infertile couples

Chlamydia (C.) trachomatis, an obligate intracellular bacterium, is responsible for the most common sexual transmitted disease and infertility. The purpose of this study was to evaluate: a) the frequency of chlamydial infection in unselected infertile couples and b) whether chlamydial infection could be identified in the semen sample as effectively as in the urethral swab of infertile patients. To accomplish this, 73 unselected, consecutive infertile couples were enrolled. Both male and female partners underwent a complete work-up to identify the cause of their infertility. A PCR method was used to detect C. trachomatis in urethral swabs and the semen samples of the male partners and in the cervical swabs of the female partners. C. trachomatis infection was found in 6 couples (8.2%). Three couples had both partners infected, 2 couples had only the male partner infected, and 1 only the female partner. C. trachomatis infection was found in the urethral swab of all 5 men infected, whereas the bacterial DNA was found in the semen sample of 2 of them. These findings suggest that C. trachomatis infection is present in about 8% of unselected infertile couples and that the bacterium should be searched in the male partner urethral swab which has a higher sensitivity.

Impact of Chlamydia trachomatis in the reproductive setting: British Fertility Society Guidelines for practice

Chlamydia trachomatis infection of the genital tract is the most common sexually transmitted infection and has a world-wide distribution. The consequences of infection have an adverse effect on the reproductive health of women and are a common cause of infertility. Recent evidence also suggests an adverse effect on male reproduction. There is a need to standardise the approach in managing the impact of C. trachomatis infection on reproductive health. We have surveyed current UK practice towards screening and management of Chlamydia infections in the fertility setting. We found that at least 90% of clinicians surveyed offered screening. The literature on this topic was examined and revealed a paucity of solid evidence for estimating the risks of long-term reproductive sequelae following lower genital tract infection with C. trachomatis. The mechanism for the damage that occurs after Chlamydial infections is uncertain. However, instrumentation of the uterus in women with C. trachomatis infection is associated with a high risk of pelvic inflammatory disease, which can be prevented by appropriate antibiotic treatment and may prevent infected women from being at increased risk of the adverse sequelae, such as ectopic pregnancy and tubal factor infertility. Recommendations for practice have been proposed and the need for further studies is identified.

Preconception lifestyle advice for people with subfertility

BACKGROUND

Infertility is a prevalent problem and has significant consequences for individuals, families and the wider community. People's chance of having a healthy, live birth may be impacted upon by factors such as weight, diet, smoking, other substance abuse, environmental pollutants, infections, medical conditions, medications and family medical history. However, there is no current guideline about what preconception advice should be offered to people presenting for infertility treatment. It is important to determine what preconception advice should be given about these types of factors to such people in order to help them to make positive changes and hopefully improve their chances of conception and delivering a healthy, live baby.

OBJECTIVES

To assess the effects of preconception advice on the chances of a live birth for people who perceive that they may be infertile and are investigating the possibility of medical treatment to address subfertility.

SEARCH STRATEGY

All published and unpublished randomised controlled trials addressing preconception advice to influence lifestyle factors in people who perceived that they may be infertile and investigated the possibility of medical treatment to address subfertility were sought from the Cochrane Menstrual Disorders and Subfertility Review Group Trials Register, Cochrane Central Register of Controlled Trials (CENTRAL), The Cochrane Library, MEDLINE, PubMed, EMBASE, PsycINFO, AMED, Cumulative Index to Nursing and Allied Health Literature (CINAHL), LILACS, trial registers for ongoing and registered trials, citation indexes, ISI Web of Knowledge, Clinical Study Results database, OpenSIGLE database, China National Knowledge Infrastructure (CNKI) Periodical Index and Google (inception to 5 October 2009).

SELECTION CRITERIA

Only randomised controlled trials (RCTs), including cluster-randomised (group-randomised) trials, that considered preconception advice given to individuals who perceived that they may be infertile and were investigating the possibility of medical treatment from subfertility specialist services were eligible for inclusion. The primary outcome was live birth, defined as delivery of a live fetus after 20 completed weeks of gestation.

DATA COLLECTION AND ANALYSIS

Two review authors independently applied eligibility criteria to, extracted data from and assessed the risk of bias in the single included trial.

MAIN RESULTS

One trial assessing smoking cessation advice for 94 infertile women smokers fulfilled the criteria for this review, but the trial did not report on the review's primary outcome of live birth or any other fertility-related outcomes. This trial of women attending a fertility clinic showed that smoking cessation advice tailored to a woman's "stage-of-change" (readiness to stop smoking) did not show significant evidence of a difference in stage (including smoking cessation rates) compared with standard clinical advice.

AUTHORS' CONCLUSIONS

No RCTs were located that assessed the effects of preconception advice on the chance of a live birth or other fertility outcomes in people who perceived that they may be infertile and were investigating the possibility of medical treatment to address subfertility. Given the lack of RCTs evaluating the effectiveness of preconception lifestyle advice for people in the afore-mentioned population, this review cannot provide guidance for clinical practice in this area. However, it does highlight the need for further research into this important subject.