Chronic pain

Chronic pain (CP) generally refers to any pain that lasts a long time. Sometimes, the duration of 3 months, or in some conditions 6 months, is used to distinguish acute (lasting for less than 3 months) and chronic pain. 

Chronic pain can involve several biological processes, including joint degeneration, inflammation (e.g., rheumatoid arthritis), tumor growth (cancer pain), damaged nerves (neuropathic pain) and can affect different body locations. CP could also be present in multi-symptom syndromes, including, for example, fibromyalgia (a condition of widespread, persistent pain) or irritable bowel syndrome. 

Attention should be paid to any kind of chronic pain, as it is always associated with ongoing or impending organ damage, and its cause should be elucidated.

Chronic pain can be associated with almost every chronic, long-lasting disease. Out of diseases that can have an impact on patient’s fertility, chronic pain is associated with these conditions:

Hydrosalpinx

A hydrosalpinx (Pic. 1) is a distally blocked fallopian tube filled with serous or clear fluid. The blocked tube may become substantially distended giving the tube a characteristic sausage-like or retort-like shape. The condition is often bilateral and the affected tubes may reach several centimeters in diameter. The blocked tubes cause infertility. The major cause for distal tubal occlusion is pelvic inflammatory disease (PID), usually as a consequence of an ascending infection by chlamydia or gonorrhea. Hydrosalpinx patients may be asymptomatic, but common symptoms include recurrent or chronic lower abdominal pain or pelvic pain, and may experience infertility.

Pelvic inflammatory disease

Pelvic inflammatory disease (PID) is an inflammatory process elicited by the migration of pathogenic microorganisms from the lower to upper genital tract. PID is often caused by Chlamydia trachomatis or Neisseria gonorrhoeae infection. The main complication is the formation of a pyosalpinx (abscess) and ectopic pregnancy is 6 times more likely after a pelvic infection. Often there may be no symptoms. Signs and symptoms, when present may include lower abdominal pain, vaginal discharge, fever, burning with urination, pain with sex, or irregular menstruation. Untreated PID can result in long term complications including infertility, ectopic pregnancy, chronic pelvic pain, and cancer. 

Endometriosis

Endometriosis is a common gynecologic disorder. This disorder is classically defined as the presence of endometrial glands and stroma outside of the endometrial lining and uterine musculature (Pic. 3). It most commonly affects women in their 20’s and 30’s. Around 50% women with pelvic pain suffer from endometriosis. Chronic pelvic or low back pain is a typical presenting symptom, often associated with changes in intensity and character of the pain related to menstrual cycle. Endometriosis can cause infertility. In endometriosis, there is a risk of female infertility of up to 30% to 50%. The mechanisms by which endometriosis may cause infertility is not clearly understood, particularly when the extent of endometriosis is low.

Uterine fibroids

Myomas, or fibroids, are the most frequently recorded benign smooth muscle tumors of the uterus, affecting 20%–60% of women of reproductive age and may negatively affect fertility and outcome of pregnancy. Typically, fibroids appear as well-defined, solid masses with a whorled appearance (Pic. 4). Uterine fibroids grow from the uterine muscle and are under the hormonal influence of estrogen, that is why they do not exist before the secretion of this hormone before puberty, and they regress with menopause. Symptoms depend on the location of the tumor and its size. Important symptoms include abnormal gynecologic hemorrhage, heavy or painful periods, abdominal discomfort or bloating, painful defecation, chronic pelvic or back pain, urinary frequency or retention, and in some cases, infertility. The majority of women with uterine fibroids will have normal pregnancy outcomes. In cases of uterine fibroids found in infertile women, a fibroid is typically located in a submucosal position and it is thought that this location may interfere with the function of the lining and the ability of the embryo to implant. Also larger fibroids may distort or block the fallopian tubes.

Chronic prostatitis

Prostatitis is a poorly defined condition and is shown to have a bacterial aetiology in 5 to 10% of cases. In the remaining proportion, the symptoms are attributed to “chronic non-bacterial prostatitis” or “chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS).” CP/CPPS is a chronic pain disorder, which is characterized by the presence of noninfectious pelvic or perineal pain lasting longer than 3 months. This syndrome is currently considered to be a multifactorial medical condition and requires a multimodal treatment approach. Chronic prostatitis negatively affects the patient’s fertility, as it decreases the quality of the semen. Inflammatory molecules and increased amount leukocytes (white blood cells) in the semen caused by the prostate inflammation have a negative effect on the characteristics of the sperm cells. Furthermore, the amount and quality of prostatic secretions (which form a significant part of the semen) are decreased, and the man may experience prolonged, or even absent semen liquefaction.

Prostate cancer 

Prostate cancer (Pic. 2) is the most common type of cancer in men. It is usually asymptomatic for a long time, as it grows slowly. When symptoms appear, the tumor is usually already advanced or metastasized. When symptoms of an early tumor are present, they usually include urinary retention, changes in bladder habits, incontinence, hematuria (blood in the urine), hematospermia (blood in the semen) and painful ejaculation. Chronic pelvic pain and pain in the bones is associated with advanced cancer, as chronic bone pain usually means that the cancer has metastasized into the bones. The treatment of prostate cancer significantly reduces male fertility. Surgical removal of a prostate leads to dry orgasms, with no semen ejaculated. Radiotherapy and hormonal therapy, commonly used in the treatment of prostate cancer, drastically reduce the number of sperm cells in the semen and the amount of semen in general. Therefore, the treatment frequently results in infertility.