Male infertility: the intracellular bacterial hypothesis

Area of Science:

• Reproductive Medicine
• Microbiology
• Public Health

Background:

• Infertility affects 1 in 7 couples, with male factors contributing to 30% of cases, often with unknown etiology.
• Current treatments for male infertility, such as intrauterine insemination and in vitro fertilization with intracytoplasmic sperm injection, are invasive, expensive, and do not address underlying causes.
• Semen analysis is the primary method for evaluating male fertility, but abnormal parameters do not always explain conception failure.

Purpose of the Study:

• To investigate the controversial role of infectious agents, specifically Chlamydia trachomatis and ureaplasmas/mycoplasmas, in male infertility.
• To explore potential mechanisms by which these bacteria may negatively impact male fertility, including effects on semen parameters and fertilization processes.
• To highlight the need for basic research to develop targeted treatments for male infertility caused by infections.

Main Methods:

• Review of existing literature on infectious agents and male infertility.
• Analysis of the impact of Chlamydia trachomatis, ureaplasmas, and mycoplasmas on semen parameters.
• Discussion of potential effects on physiological fertilization mechanisms not routinely assessed.

Main Results:

• The role of Chlamydia trachomatis in male infertility remains debated, despite its known impact on female fertility.
• The association between ureaplasmas/mycoplasmas and male infertility is also under investigation.
• Infections may affect male fertility through mechanisms beyond standard semen analysis, including fertilization processes.

Conclusions:

• Infectious processes are plausible contributors to male infertility of unknown origin.
• Further basic research is crucial to elucidate the precise impact of bacteria like Chlamydia trachomatis, ureaplasmas, and mycoplasmas on male fertility.
• Understanding these mechanisms could lead to targeted therapies, offering alternatives to assisted reproductive technologies like intracytoplasmic sperm injection.