Sexually transmitted infections (STIs) are conditions passed from person to person primarily through sexual contact. Infertility refers to the inability to conceive after a period of unprotected intercourse. Untreated STIs can lead to infertility, making early detection and treatment important.
Mechanisms of STI-Induced Infertility
Untreated STIs can damage the reproductive system, leading to infertility in both men and women. Infections trigger inflammation in various reproductive organs. Persistent inflammation can form scar tissue, obstructing reproductive pathways and preventing the normal movement of eggs, sperm, or fertilized embryos.
These blockages physically impede conception by creating barriers that prevent sperm from reaching an egg or a fertilized egg from implanting. The inflammatory process can also directly harm reproductive cells and tissues, impairing the function of organs responsible for egg and sperm production and reducing their quality or quantity.
STIs Affecting Female Fertility
Untreated bacterial STIs commonly cause infertility in women, primarily through pelvic inflammatory disease (PID). Chlamydia and gonorrhea are the most frequent culprits, accounting for about 90% of PID cases. These bacteria can ascend from the vagina or cervix to infect the uterus, fallopian tubes, and ovaries. This leads to inflammation, scarring, and potential blockage of the fallopian tubes, which are crucial for egg transport and fertilization.
PID often causes tubal factor infertility, preventing sperm from reaching the egg or a fertilized egg from implanting. Approximately 10-15% of women with untreated chlamydia or gonorrhea develop PID, and up to 15-20% of women with PID may experience infertility. Untreated PID also increases the risk of ectopic pregnancy, a dangerous condition where a fertilized egg implants outside the uterus. Other STIs like Mycoplasma genitalium can contribute to tubal scarring, and certain Human Papillomavirus (HPV) strains, if leading to cervical cancer, may necessitate fertility-affecting treatments.
STIs Affecting Male Fertility
STIs can affect male fertility through inflammation and damage to reproductive organs. Chlamydia and gonorrhea are leading causes of epididymitis, an inflammation of the epididymis, the coiled tube that stores and transports sperm. This inflammation can cause swelling and pain, and if untreated, may lead to scarring and blockages within the sperm transport system, making it difficult for them to be released during ejaculation.
Chlamydia can also cause prostatitis (inflammation of the prostate) and impact sperm quality, reducing motility, count, and increasing DNA fragmentation. Untreated orchitis, inflammation of the testicles often linked with epididymitis, can affect sperm production and, in rare cases, lead to testicular shrinkage. While syphilis does not directly cause male infertility, its complications can lead to epididymitis and sperm transport blockages. Genital herpes may also be associated with lower sperm counts.
Preventing STI-Related Infertility
Preventing STI-related infertility requires proactive measures and timely medical care. Consistent and correct use of barrier methods, such as condoms, during sexual activity significantly reduces STI transmission. Limiting sexual partners also helps minimize exposure to infections.
Regular STI testing is crucial, especially for sexually active individuals, as many STIs, including chlamydia and gonorrhea, often have no noticeable symptoms. Annual screening for chlamydia and gonorrhea is recommended for sexually active women under 25, and for older women with risk factors. Early diagnosis allows for prompt and complete treatment, preventing long-term damage to reproductive organs. Ensuring all sexual partners are tested and treated helps prevent reinfection and further spread.