Chlamydia and Male Infertility: Prevalence and Impact
Approximately 3% of men with chlamydial infections develop infertility, though this estimate is based on limited evidence. 1
Epidemiology and Clinical Impact
Chlamydia trachomatis is the most common sexually transmitted bacterial infection worldwide, with an estimated 3 million new infections annually in the United States. While much attention has focused on female complications, the prevalence of infection is similar between males and females 2.
Key facts about chlamydia in men:
- 70-90% of infections are asymptomatic 3
- When symptomatic, typically presents as urethritis with discharge and dysuria 3
- Can cause epididymitis, which may lead to infertility 4, 1
Pathophysiology of Male Infertility from Chlamydia
Chlamydial infection can affect male fertility through several mechanisms:
- Direct damage to sperm, impairing parameters, increasing DNA fragmentation, and reducing acrosome reaction capacity 2
- Infection of the testis and prostate, leading to deterioration of sperm quality 2
- Development of epididymitis, which can cause scarring and obstruction 4
Evidence for Association with Infertility
The evidence linking chlamydia to male infertility has been more limited than for female infertility, but several important findings exist:
- Men from couples with idiopathic infertility are significantly more likely to have antibodies to C. trachomatis at titers ≥1:64 compared to first-time expectant fathers 5
- Higher antibody titers correlate with higher odds ratios for infertility 5
- Past infections appear more strongly related to male infertility than current infections 6
- The proportion of male partners in infertile couples with evidence of chlamydial infection exceeds that in the general population 2
Clinical Implications and Screening
The CDC notes that chlamydial infections among men rarely result in sequelae, though they can cause nongonococcal urethritis and acute epididymitis 4. However, the evidence suggests that the impact on male fertility may be underappreciated.
Screening considerations:
- Annual screening is recommended for all sexually active women <25 years 4
- Screening of sexually active young men should be considered in high-prevalence settings (adolescent clinics, correctional facilities, STD clinics) 4
- Half of men who test positive for chlamydia antibodies have no history of genitourinary symptoms, highlighting the importance of screening beyond symptomatic cases 5
Treatment and Prevention
Effective treatment is essential to prevent complications:
- Recommended regimens: azithromycin 1g orally in a single dose or doxycycline 100mg orally twice daily for 7 days 3
- Treatment efficacy exceeds 95% 6
- Partners should be treated to prevent reinfection 3
- Abstain from sexual intercourse until both partners complete treatment 3
Conclusion
While the 3% estimate for male infertility following chlamydial infection provides a baseline figure 1, the true prevalence may be higher due to the asymptomatic nature of many infections and limited research specifically addressing male fertility outcomes. The evidence clearly demonstrates that chlamydia can impact male fertility through multiple mechanisms, and appropriate screening, diagnosis, and treatment are essential for preserving reproductive health.