Chlamydia is one of the most common bacterial sexually transmitted infections globally, caused by the bacterium Chlamydia trachomatis. This infection is a public health concern because it frequently presents without noticeable symptoms, allowing it to persist undetected for long periods. If left untreated, the infection can ascend into the upper reproductive tract in both sexes, leading to severe and potentially irreversible complications. Chlamydia significantly affects fertility, as the resulting inflammation and damage are a major preventable cause of infertility in women and can also impair male reproductive function.
The Mechanism of Reproductive Damage in Women
An untreated Chlamydia infection in women typically begins in the cervix, but the bacteria can travel upward to the uterus, fallopian tubes, and ovaries. This upward spread of the bacteria triggers an inflammatory response known as Pelvic Inflammatory Disease (PID). Estimates suggest that between 10% and 15% of women with an untreated lower genital tract Chlamydia infection will develop PID.
The body’s immune reaction results in inflammation and subsequent formation of scar tissue within the delicate fallopian tubes. This scarring can partially or completely block the tubes, which prevents the egg from meeting sperm for fertilization, a condition called tubal factor infertility. Even a partial blockage can be dangerous, as it may allow fertilization to occur but then trap the fertilized egg, causing a life-threatening ectopic pregnancy.
Repeated Chlamydia infections are thought to increase the degree of tubal damage and the risk of long-term reproductive complications. The severity of the damage is often linked to the duration of the infection before treatment. Because the infection is often asymptomatic, significant damage can occur without the person ever feeling sick.
Effects on Male Reproductive Health
In men, Chlamydia trachomatis primarily infects the urethra, but the bacteria can travel through the reproductive tract, causing inflammation in various structures. The most common complication affecting male fertility is epididymitis, which is an inflammation of the epididymis, the coiled tube that stores and transports sperm from the testicles. This inflammation causes pain and swelling in the testicular area and can lead to blockages within the epididymis, preventing the normal release of sperm.
The infection may also directly impair the quality of the sperm itself, even without causing a physical blockage. Studies have shown that Chlamydia can negatively affect sperm parameters, including reduced motility, meaning the sperm do not swim effectively. Furthermore, the infection is associated with an increase in sperm DNA fragmentation, which can compromise the sperm’s ability to successfully fertilize an egg.
While Chlamydia-related infertility is considered less common or severe in men compared to women, it remains a significant contributing factor to male factor infertility. Prompt antibiotic treatment is effective at clearing the infection and is important to prevent blockages in the epididymis and to potentially improve sperm quality.
Recognition, Treatment, and Prevention
A major challenge in controlling the spread of Chlamydia and preventing long-term damage is its frequently asymptomatic nature. Most infected individuals, both men and women, experience no symptoms at all, which is why it is often referred to as a “silent epidemic.” When symptoms do occur, they are often subtle, such as mild discharge or painful urination, and can be easily ignored.
Because of the high rate of silent infection, regular screening is the most effective strategy for early detection and prevention of fertility damage. Health organizations recommend annual testing for sexually active women under the age of 25 and for older women with certain risk factors, such as new or multiple partners. Testing involves a simple urine sample or a swab and is reliable for diagnosis.
Fortunately, Chlamydia is a bacterial infection that is easily and effectively treated with antibiotics. Common treatment regimens include a single dose of azithromycin or a seven-day course of doxycycline. Prompt treatment is paramount, as antibiotics can stop the infection from progressing and causing further damage. However, antibiotics cannot reverse scar tissue that has already formed. Prevention methods, such as the consistent use of barrier methods during sexual activity, remain the most reliable way to avoid initial infection and protect long-term reproductive health.