Infertility: from causes and fertility tests to diagnosis

According to the World Health Organization (WHO), infertility (or sterility) is defined as the failure of a couple to achieve pregnancy after 12 months or more of regular unprotected sexual intercourse. Sterility affects around 48 million couples around the world. According to official figures, one in every five couples in Switzerland is unable to get pregnant. The actual number is likely to be higher, since many infertile couples don’t consult a medical professional.

There are many potential reasons for infertility. Men and women alike can experience difficulties in trying to conceive. Read on to find out more about the most common causes of infertility in both genders.

Universal causes of sterility

Some factors have an influence on fertility in both men and women:

• Age: The most decisive factor in infertility is age. All over the world – Switzerland included – couples are having children later in life. Age is particularly important in cases of infertility in women. This is because women are born with a limited number of egg cells, and this figure gradually diminishes over time. This decline speeds up around the age of 35. As the years progress, the egg cells are also more likely to suffer genetic damage, which increases the risk of miscarriage. Men experience a decline in their sperm count and the quality of their sperm cells as they get older, and both factors have an impact on male fertility. Women who want to counter the effects of ageing on their egg cells may consider social freezing as an option. Men can also choose to have their sperm cells frozen.
• Weight: Bodyweight can have an influence on fertility in some cases. Researchers have found that men of normal weight have a higher sperm count and better sperm quality than those who are overweight. It’s not yet clear why that is. Being overweight also has a negative effect on fertility in women. Women with a body mass index (BMI) over 30 are three times more likely to be sterile than women with a BMI of between 18.5 and 24.9.
• Sexually transmitted diseases: STDs such as chlamydia and gonorrhoea can lead to infertility in men and women. This happens when the infection spreads to the testicles, the woman’s pelvic area or the fallopian tubes.
• Certain medications: Immunosuppressants, antidepressants and medication to lower blood pressure can all increase the risk of infertility.
• Lifestyle: Prolonged periods of mental stress and mentally challenging situations can leave you infertile. Excessive consumption of alcohol and nicotine also have an effect on fertility. The same goes for environmental pollutants (e.g. pesticides and heavy metals). Another influencing factor is poor nutrition.

Reasons for infertility in men

There are various gender-specific causes of infertility in men that can leave couples unable to have children:

• Testicular inflammation: Inflammation of the testicles can sometimes lead to infertility. This is why there is a risk of mumps causing infertility in men. In some cases, this infectious disease can cause such severe swelling in the testicles that their long-term functioning is impaired. Infertility can also be caused by an infection of the prostate, urethra or epididymis (the tube that connects the testicles to the vas deferens).
• Varicose veins: Varicose veins in the testicles (varicocele) can also cause infertility. However, the link has not yet been clearly established. Researchers suspect that varicose veins may have an effect on the mobility and density of sperm cells.
• Undescended testicles: Undescended testicles (maldescensus testis) are often associated with infertility, particularly in cases where both testicles are affected.
• Tumours: Testicular cancer can often cause infertility, especially if both testicles are affected. It is usually the treatment (operation, radiotherapy, chemotherapy) that will leave the patient infertile.
• Diabetes: In certain cases, diabetes can cause infertility in men. Higher blood sugar levels lead to a reduction in the sperm count. Diabetes can sometimes cause damage to the DNA of sperm cells.
• Operations and injuries: Certain injuries and operations (e.g. for a hernia) can lead to infertility in men if they cause a blockage in the vas deferens or epididymal ducts. This can prevent sperm from reaching the ejaculate.
• Genetic factors: Infertility is also caused by genetic factors such as Klinefelter syndrome. Boys and men with this syndrome are born with two X chromosomes and one Y chromosome, instead of the usual XY combination. Hereditary diseases such as cystic fibrosis also often lead to sterility in men.
• Hormonal causes: If the body doesn’t produce enough testosterone, this can have a negative effect on fertility. Low levels of testosterone may be caused by underactive testicles (hypogonadism).
• Immune responses: In rare cases, the body may react against its own sperm cells by producing antisperm antibodies. This is usually referred to as male autoimmune infertility.

Reasons for infertility in women

Infertility in women also has various potential gender-specific causes:

• Endometriosis: One reason for infertility in women is endometriosis. This is when cells from the endometrial lining grow outside the uterus. It can often affect the functioning of the ovaries and fallopian tubes. Cysts can also sometimes form on the ovaries, which is another contributing factor to infertility.
• Myomas: Myomas are benign tumours that form in the uterus. Several of these tumours will often appear at the same time. Between 30% and 50% of women of childbearing age are affected, and myomas can often lead to infertility.
• Prolactinomas: In certain cases, sterility may be due to prolactinomas. These benign tumours form on the pituitary gland (hypophysis) and cause the body to increase production of the hormone prolactin, which prevents ovulation.
• Tumours: Illnesses such as cervical and ovarian cancer and their treatment are increasingly causing infertility in women.
• PCOS: Polycystic ovary syndrome (PCOS) is often associated with infertility. Women with PCOS produce increased amounts of male hormones. PCOS also causes numerous cysts to form on the ovaries, which increases the risk of infertility.
• Thyroid problems: Cases of hyperthyroidism and hypothyroidism (excess or deficient hormone production by the thyroid gland) can sometimes lead to sterility.
• Immune responses: Another cause of infertility in women is the body’s defences reacting against its own egg cells or the partner’s sperm cells.
• Genetic factors: There are also genetic causes of sterility in women. One example is Turner syndrome, in which one of the sex chromosomes is missing. This causes the ovaries to malfunction and causes infertility.
• IUD infections: Infertility can sometimes be caused by an infection in the uterus or fallopian tubes. There is a slightly increased risk of developing this kind of infection in the first few weeks following the insertion of an IUD.

By the way, there is no established link between HPV vaccinations and sterility. Although there are side effects to the HPV vaccination, it does not lead to infertility. Incidentally, diabetes does not cause infertility in women, in contrast to men.

There are various fertility tests available for men and women. You can find out more about the different options below.

Fertility tests for men

If you are a man and you suspect you may be infertile, the best thing to do is discuss the possible signs with a urologist. They will start by taking a look at your medical history. Relevant factors can include previous infections, illnesses and cycle irregularities in your partner. If you are a man planning to have children, you can also get support at a fertility centre.

Your doctor will then perform a physical examination, paying particular attention to your reproductive organs. You will probably have to have a semen analysis. The process is as follows:

• You produce a sample for the semen analysis by masturbating in a dedicated, private room at the urology practice. You will be given a container to collect your sample.
• The practice then sends your sample to a laboratory within one hour so they can conduct a semen analysis. The analysis includes parameters like sperm count, volume, motility (the proportion of mobile sperm), morphology (the proportion of normally formed sperm) and the pH value. The laboratory compares these values against the normal ranges for a semen analysis.

The normal ranges for the above parameters are:

• Sperm count: at least 39 million
• Volume: at least 1.5 ml
• Motility: at least 32%
• Morphology: 4%
• pH value: 7 to 8

And what does semen look like if you are infertile? You can’t tell with the naked eye. However there are certain signs that you should see a doctor about. For instance, if your sperm has a yellowish hue, this could indicate an infection. You should also seek medical advice if your sperm is clear and see-through. This could mean an important component is lacking. As a general rule, you should talk to your doctor if you have any reason to suspect you might be infertile.

Fertility tests for women

If you are a woman and you suspect you might be infertile, consult your doctor about the potential signs. After looking at your medical history, doctors will normally perform a palpation (manual examination) and an ultrasound examination. In suspected cases of sterility, there are various fertility tests your gynaecologist can offer:

• Hormone analysis: This will usually involve an anti-Müllerian hormone (AMH) test. AMH concentration in the body gives doctors an idea about your ovarian reserves. They will also conduct a follicle-stimulating hormone (FSH) analysis. In some cases, your healthcare professional will also measure your thyroid hormones or other hormones such as prolactin and testosterone.
• HyCoSy: Hysterosalpingo-contrast sonography, or HyCoSy, is one of the most common fertility tests for women. It is used to determine tubal patency; in other words, it allows your doctor to test whether your fallopian tubes are open or blocked. To do this, they will insert a catheter into the cervix and inject a contrast agent into the uterus. This then flows into the fallopian tubes and the ovaries, provided there is no blockage. When doctors test the patency of fallopian tubes, they use ultrasound to observe and interpret the flow of the contrast agent. Since HyCoSy cannot be used to diagnose endometriosis, a laparoscopy may also be necessary in some cases.
• Laparoscopy: A laparoscopy is a surgical procedure carried out under general anaesthetic. It allows your doctor to examine your ovaries, fallopian tubes and uterus by making a small incision in the stomach and inserting a laparoscope with a camera. The doctor will use a solution to see if your fallopian tubes are open. They will also be able to remove any endometrial tissue, cysts or myomas they see during the procedure.

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