Causes Of Infertility

1 Causes of Infertility

The causes of infertility, or more often, subfertility are numerous and complex. Infertility is still thought of as a problem of the female reproductive system by many couples. However, while this may be true in some, often it is the male partner who has a problem. Less commonly, there may be a problem with both the male and female in the couple. Roughly speaking, problems with infertility in couples can be traced to the female in approximately 40% of cases, to the male in 40%, to both the male and female in 10% and remains unexplained in another 10% of cases.

The causes of infertility are therefore best divided into male and female.

Causes of Infertility in Women

1. Most commonly, reduced fertility in women is caused by problems with ovulation. Women may have menstrual cycles where no ovulation has occurred (anovulation or anovulatory cycles) or where ovulation occurs erratically. Sometimes, ovulation fails completely. Conditions where ovulation is at fault include;

Hormonal problems such as polycystic ovarian syndrome and many others,
Weight problems: either being over or underweight,
Aggressive exercise,
Ovarian cysts,
Medicines: side effects of many medicines such as pain killers and especially chemotherapy,
Radiation exposure: in cancer therapy or accidental exposure,
Exposure to other chemicals or toxins,
Genetic problems,
Emotional problems,
Early menopause.

2. Fertility problems may be caused by factors which affect the Fallopian Tubes. These include;

Endometriosis: a condition where the normal womb lining (endometrium) can appear in other places in the body. Most commonly, this can include any of the other pelvic organs such as the outer surface of the uterus, the ovary, the fallopian tubes or urinary bladder. But other organs including bowels and even lungs can be affected by this condition.
Infections such as sexually transmitted diseases: these include Chlamydia and gonorrhoea which can cause damage by scar tissue formation in the uterus or fallopian tubes. Infection with these organisms can lead to Pelvic Inflammatory Disease.
Uterine Fibroids which can compress or damage the fallopian tubes.
Ovarian Cysts
Surgery to any part of the female reproductive system.
Trauma

3. Infertility can also be linked with maternal age. Normal fertility levels fall sharply after women reach 35 years of age and fall very steeply after they reach 40 years.

4. Problems with other aspects of the reproductive system such as congenital malformations of the uterus or vagina. These can interfere with any aspect of pregnancy from sexual intercourse, travel of sperm up the female reproductive tract, to implantation.

5. Problems with the cervical mucous: during ovulation, the mucous should be conducive to sperm readily being transferred through the cervix and on into the uterus. But sometimes, the mucous is an inhospitable environment for sperm and most are killed. This may occur if the female produces anti-sperm antibodies.

6. Stress and anxiety: although this is slightly controversial, stress, tension and anxiety symptoms can cause problems with almost any aspect of falling pregnant.

7. Other co-existing medical problems; if poorly controlled or inadequately treated, many common chronic medical conditions can lead to problems with any aspect of pregnancy. Examples of such conditions include heart disease, diabetes, thyroid disorders and many more.

Causes of Infertility in Men

Infertility or reduced fertility in men is usually caused by some aspect of sperm production or transfer to the female partner. Sperm may be produced in inadequate numbers (oligozoospermia) or there may be a complete lack of sperm production (azoospermia). Even if normal quantities of sperm are produced, they may be poorly formed or shaped (poor morphology) or they may not swim well (poor motility). There may be a combination of any of these problems.

Causes of problems with sperm production and transfer include;

Hormonal problems: lack of testosterone or LH,
Sexually Transmitted Infections such as Chlamydia or gonorrhoea,
Other infections such as some viral infections can cause inflammation of the testes, e.g. mumps,
Medicines: side effects of many medicines such as chemotherapy,
Taking anabolic steroids,
Illegal drugs and other elicit substances such as cannabis and marijuana,
Exposure to other chemicals or toxins such as heavy metals,
Radiation exposure: in cancer therapy or accidental exposure,
Tumours of the testes as well as the treatment of these,
Heat: sperm are particularly sensitive to hot environments e.g. saunas, hot baths, wearing tight fitting underwear or trousers,
Varicoceles: these are similar to varicose veins in legs. Veins in the scrotum dilate and enlarge,
Congenital malformations of any aspect of the male reproductive tract including testicles and penis,
Impotence: this can stop the successful transfer of otherwise normal sperm into the vagina,
Emotional problems: this can cause impotence,
Surgery of the male reproductive tract for any cause,
Testicular damage from torsion of the testicle,
Retrograde ejaculation caused by prostate surgery and other causes. This causes ejaculation backwards into the urinary bladder instead of the penis,
Premature ejaculation: the sperm may not be transferred in adequate numbers to the vagina,
Trauma: may damage the testes or penis,
Non-descended or partially descended testes; testes usually develop in the lower abdomen and descend in the latter stages of pregnancies or after birth into the scrotum. If this process does not occur fertility can be reduced and the testes can be at greater risk of developing cancer.
Other co-existing medical problems; if poorly controlled or inadequately treated, many common chronic medical conditions can lead to problems with sperm production or transfer. Examples of such conditions include heart disease, diabetes, thyroid disorders and many more.
Overweight: this can affect the quality of the sperm and also cause difficulties with sexual intercourse.
Auto-immune disorders: in some instances, the body's own defence system attacks its own sperm,
Genetic disorders: such as Cystic Fibrosis and other chromosomal abnormalities can cause infertility.

Some of the more common causes of female infertility or subfertility are discussed below in more detail.

Polycystic Ovarian Syndrome

Polycystic Ovarian Syndrome (PCOS) is a very common condition. In the UK, it is thought to affect as many as 10% of the female population of reproductive age. Consequently, it is perhaps the commonest cause of failure to conceive. PCOS is also sometimes called Stein-Leventhal Syndrome.

The function of ovaries in the female is to store the supply of eggs and then to release an egg to make it available for fertilisation. Ovaries also produce oestrogen, progesterone and small quantities of the male hormone testosterone. As is discussed above in detail, ovulation occurs normally on a regular cyclical basis approximately once a month. The egg matures in a follicle or cyst in the ovary before ovulation occurs. Although normally only one egg is released during each cycle, several follicles start to develop initially, with the most mature egg finally being shed at ovulation.

However, in PCOS, several follicles do start to develop but none develops enough to reach maturity. Therefore, sometimes, no eggs are released. No ovulation takes place in these cycles - anovulation. Hormonal problems also occur with raised levels of testosterone being produced. LH levels can also to elevated.

Symptoms of PCOS

There are several well recognised symptoms of PCOS. But some women have very mild symptoms while others have severe problems. Some of the commonest symptoms are;

Irregular periods
Light periods (oligomenorrhoea)
No periods (amenorrhoea)
Failure to conceive due to the period problems (causing anovulation) and other factors
Weight gain
Acne
Excessive hair grow (hirsutism) affecting facial skin, limbs and the trunk
Thinning of scalp hair or male pattern baldness.

The symptoms are most frequently found in women in the late teens and into their twenties. Most women with this condition are unaware of it.

Having PCOS can also cause a raised cholesterol level, cause raised blood pressure and increase the likelihood of diabetes due to an increase in insulin resistance. This means the insulin produced normally by the pancreas to reduce glucose levels in the blood does not have the same effect. Blood sugars therefore are elevated long term giving rise to diabetes and its complications. Women who remain amenorrhoeic (have no periods) for many years are at higher risk of developing endometrial carcinoma (cancer of the lining of the womb).

Causes of PCOS

The exact cause of PCOS is still not fully understood. However, there does seem to be a genetic component to this condition as it can run in families.

The role of insulin and insulin resistance is described above. This seems to be an important factor in PCOS, particularly in women who are overweight, although thin women can also have PCOS. The lack of response to insulin causes an elevation in insulin levels. This in turn causes the ovaries to produce more testosterone. Together, the elevated levels of these two hormones interferes with the maturation process of the follicles, leading to a failure in ovulation. Many of the symptoms listed above are caused by the excess of testosterone.

The above situation is compounded by being overweight as having excess fat causes a further increase in insulin production. But, excess insulin leads to being overweight and therefore, women who are overweight and have PCOS can find that losing weight is a particular struggle.

Diagnosing PCOS

Diagnosis of PCOS is usually based on the following findings;

The symptoms of PCOS as listed above
Ultrasound scan findings: the ovaries appear enlarged, with multiple cysts
Blood tests: such as testosterone and LH levels.

The Treatment of PCOS

1. Weight loss: although this can be difficult, losing weight can greatly affect the symptoms of PCOS. As fat is lost, insulin levels start to decline as an excess is no longer required. This in turn causes the level of testosterone to fall also, thereby improving the chances of ovulation. Many of the "male" symptoms listed above will also then start to reverse as testosterone levels decline.

2. Anti-androgenic (anti-male hormone) drugs can be used to reverse the male type symptoms. Examples of these drugs include cyproterone acetate (found in Dianette or Diane 35 and other drugs) or spironolactone.

3. Combined oral contraceptive pill (COC): this can be used to induce regular (though artificial) periods and therefore reduce the risks of endometrial cancer. Sometimes, though less often, the progesterone only pill (POP) may be used but the results are usually less predictable.

4. Metformin: this drug is usually used to treat Diabetes Mellitus Type 2. It works by reducing insulin resistance in these diabetic patients. It therefore seems to have an increasing role in the treatment of PCOS for the same reason.

5. Clomiphene: for the purposes of conception, clomiphene may be used to induce ovulation by stimulating the ovaries.

Endometriosis

Endometriosis is another common condition. The main feature of this is the finding of endometrial cells (the lining of the womb) in other parts of the body. Diagnosis most often occurs in women aged 25-40 years. Endometriosis can affect almost any part of the body. Abnormal sites for endometrium include pelvic organs such as the outside of the womb, the vagina, fallopian tubes and ovaries. It can also include abdominal organs such as the liver, stomach or intestines and also the thorax with the lung being involved although this is rare.

The endometrium which lines the uterus undergoes monthly changes of thickening and breakdown if no pregnancy occurs. This breakdown leads to menstrual blood loss to empty the uterus in preparation for the next cycle. The endometrium present in other abnormal sites undergoes the same process of thickening and development initially, followed by breakdown and bleeding. However, as there is no outlet for these cells and blood, symptoms of pain, swelling and bleeding develop in these areas. This eventually leads to irritation of the surrounding tissues and organs with inflammation and scar tissue formation. As with many conditions, symptoms vary in severity in different women from mild to severe.

Symptoms of Endometriosis

Many women have no symptoms and the condition is diagnosed incidentally. But, common symptoms include;

Painful periods (dysmenorrhoea)
Heavy periods (menorrhagia)
Pelvic or lower abdominal discomfort and pain
Pain during sex (dyspareunia)
Pain at other times in the menstrual cycles
Back pain
Failure to conceive

Less commonly, women also complain of;

Pain on urination or difficult with urinating
Rectal bleeding
Blockage of the bowel
Coughing up blood (haemoptysis)

The presence and severity of these symptoms depends on where your abnormal endometrial tissue is located.

Causes of Endometriosis

The exact cause of endometriosis remains unclear, but possible explanations include;

1. Retrograde Menstruation: when endometrial tissue breaks down, most leaves through the cervix and vagina as menstrual blood. But it is thought that some flows upwards through the fallopian tubes and into the abdomen. Once there, the endometrial cells embed themselves onto the surface of pelvic and abdominal organs.

2. Genetic: endometriosis is commoner in Asian women, less common in Caucasians and least common in Afro-Caribbeans. It can also be traced in families suggesting a genetic link.

3. Spread via the blood or lymphatic circulation: endometrial cells may spread via these circulatory systems and travel to distant parts of the body. This may explain how cells are found in the eyes or the brain, although this occurs rarely.

4. Metaplasia: this is when one cell type changes to another cell type. It has been postulated that there may be a developmental problem in the foetal womb, thereby giving rise to endometriosis in later life. Uterine cells may be responsible for cell transformation.

5. Immune disorder: it is thought that affected women have a deficiency in their immune system. They are therefore unable to clear these abnormal cells from their bodies.

Diagnosing Endometriosis

Diagnosis is usually suspected from the clinical symptoms which women have. For confirmation, a procedure known as a laparoscopy is done under general anaesthetic. A thin tube with a light and camera is inserted into the appropriate area (usually the lower abdomen and pelvis) to view the inside of the body. Any suspected areas are biopsied (a small sample is taken) for analysis.

Treatment of Endometriosis

Treating this condition can sometimes be difficult as there is no one specific cure. Treatment aims to reduce the symptoms and sometimes to reduce the areas of endometrial patches in different abnormal locations. The various methods used for this are outlined as follows;

1. Pain Management: standard pain killers such as paracetamol or codeine containing preparations can be used to reduce and relieve pain. In addition, anti-inflammatory medication such as ibuprofen, diclofenac or mefenamic acid tablets may be used to reduce areas of swelling and inflammation which cause pain.

2. Hormone therapy: there are various types of hormonal drugs that are used to block the development of abnormal endometrial activity. These aim to reduce the effects of oestrogen which are crucial in driving the condition. These hormones therefore enable a body to either mimic an artificial pregnancy or the menopause. The main hormone treatments are;

Progestogens: these stop ovulation
Anti-progestogens (testosterone derivatives): induces a menopause like state by reducing oestrogen and progesterone.
Combined oral contraceptive pill (COC): this can help with mild endometriosis symptoms by stopping ovarian function and block the menstrual cycle.
Gonadotrophin releasing hormone (GnRH) analogues: cause a menopause like state.

3. Surgery: this can be used either to remove individual areas of endometrial tissue using laparoscopic surgery or by removal of the uterus (hysterectomy) if no further children are planned.

4. A watch and wait approach can be tried for those women with mild symptoms as occasionally, the condition resolves by itself. If it does not, any one of the above options can then be tried.