Causes of infertility

An unfulfilled desire to have children can have a variety of causes. Fertility problems can originate from one or both partners – in equal parts from the man and the woman (40% each). In 20% of cases, the fertility problem is either with both partners or cannot be detected with current technical means. Absolute infertility – for example, when both fallopian tubes are missing (which connect the ovaries to the uterus and are responsible for transporting the fertilized egg from the ovary to the uterus) or when there are no sperm in the seminal fluid at all – is extremely rare. In most cases, there is reduced fertility, i.e. there are relative changes or limitations in fertility that make it difficult to conceive. Even in these cases, spontaneous pregnancy can technically occur, but trying to conceive can become a long, tedious, and psychologically exhausting endeavor. In these cases, we, the ReproCreate fertility clinic, can help you.

In women, the absence of pregnancy is most often due to a hormonal disorder that prevents ovulation or the follicles do not develop sufficiently. An example of such a hormonal disorder is polycistic ovary syndrome (PCOS), which leads to an excess of male hormones in the female body.

Another common cause of fertility problems is dysfunction of the fallopian tubes. These functional disorders are usually caused by adhesions as a result of inflammation, surgery or, in particular, as a result of endometriosis, a spread of uterine lining outside the uterine cavity (e.g. on the fallopian tube, ovaries and abdominal cavity) leading to chronic inflammation, bleeding and tissue scarring, which affects 7 to 15 percent of women of childbearing age.

Another key factor in reduced fertility is the age of the woman. From the age of 35, the continuous degradation of oocytes accelerates significantly, and egg quality also decreases with age: from the maternal age of 38 years, the risk of chromosomal maldistribution in the embryo increases significantly.

Other causes that can contribute to reduced fertility include genital malformations (e.g. an altered shape of the uterus), blood clotting disorders, fibroids (benign nodules of the uterine wall), as well as inflammation and infection.

In men, the most common cause of infertility is reduced sperm quality, i.e. insufficient production of normally-shaped, motile sperm cells (50% of cases). In order for a man to conceive a child naturally, the seminal fluid must meet the following three criteria:

• One milliliter of seminal fluid must contain a minimum of 10 million spermatozoa (seminal threads) (concentration),
• At least 5% of these spermatozoa must be normally shaped (morphology), and
• At least 20% of the spermatozoa must be well motile and move forward at a speed of at least 25 microns/second (motility).

Possible reasons for a disorder of semen function are heavy nicotine or alcohol consumption, uncorrected undescended testicles, hormonal disorders (e.g. due to anabolic steroid consumption), past operations and infections on the testicle (e.g. due to testicular inflammation as a result of mumps). Genetic changes are also a possible cause, especially if no clear cause can be determined – as is the case with many cases of male infertility.

In rare cases, male fertility disorders can also be due to changes around the testicles, e.g. varicose veins (varicocele) in the vascular system of the testicles or tumors in the tissue of the testicles or epididymis.

Unfortunately, according to the current state of the art, it is not possible to find the exact cause of reduced semen quality in almost 50% of cases.

3. Common causes of infertility

In addition to the specific causes of fertility problems for both men and women, there are also a number of general factors that can reduce fertility and contribute to the non-occurrence of the desired pregnancy. In about 10% of couples with an unfulfilled desire to have children, no organic or hormonal causes can be identified. In these cases, one or more of the following factors could be to blame for preventing pregnancy from occurring.

3.1. Body weight

Both overweight and underweight have a significant effect on hormone secretion and thus fertility, and – in both women and men. In addition to the fact that obesity can lead to a number of serious diseases, adipose tissue releases messenger substances and enzymes that disrupt the hormonal balance and reduce fertility in women and men. In women, for example, an increased hormone level due to obesity leads to ovulation disorders, an increased occurrence of inadequately matured eggs and a worse chance of fertilized cells implanting in the uterus – even with artificial insemination. Almost 50% of Austrians weigh too much, so being overweight or reducing excess weight should not be neglected when trying to have children.

Being underweight can also make it difficult for the desired pregnancy to occur. In many cases, (severe) underweight is associated with malnutrition, which disrupts the female cycle and can cause irregular or absent menstrual bleeding.

3.2. Alcohol, Nicotine and Anabolic Steroids Hormones

Alcohol consumption contributes to reduced fertility in both men and women. Women who want to become pregnant should generally avoid alcohol altogether: the period from the 5th to the 12th week of pregnancy, when the child’s organs are created, is particularly sensitive to the negative effects of alcohol on the embryo.

The use of anabolic steroids should not be neglected in the case of fertility disorders and infertility: in men who take anabolic steroids, sperm production is reduced, there is an increased loss of libido and erectile dysfunction – in some cases even the testicles shrink. Depending on the duration and extent of anabolic steroid use, as well as the type of preparation, male fertility can suffer lifelong damage.

Nicotine consumption also has negative effects on fertility. Infertility rates are almost twice as high among smokers as among non-smokers. It has been scientifically proven that the quality of paternal seminal fluid decreases with smoking – both in terms of sperm motility (motility) and the likelihood of malformed sperm (morphology). In women, nicotine and other harmful substances to which one is exposed when smoking (e.g. carbon monoxide and cyanide) accelerate the breakdown of eggs. This can lead to premature menopause (switching). In addition, the genetic material of eggs and sperm suffers from the influence of nicotine and other chemicals in cigarettes. Since smoking also increases the risk of miscarriage and lower infant birth weight, we strongly recommend that you give up smoking if you want to have children or are already pregnant.

3.3. Genetic alterations

Genetic changes can also be responsible for infertility or problems with getting pregnant or successfully carrying a pregnancy to term.

In men, for example, an AZF deletion, i.e. a partial absence of the Y chromosome in one of the so-called AZF regions, causes a very low sperm concentration (1 million sperm per millilitre, oligospermia), which makes it impossible to conceive a child naturally – in general, a concentration of at least 10 million sperm per millilitre of seminal fluid is required. It is also possible that Klinefelter syndrome is responsible for infertility, in which affected men have one X chromosome too many (XXY). One in 1000 male children is born with this chromosomal abnormality, which also has a lower secretion of male hormones, a lower quality of sperm. Often, the sperm concentration is even completely adjusted, which leads to a complete absence of sperm in the seminal fluid (azoospermia).

In women, gene changes, such as in the FSH receptor, which is responsible for the development of the follicles (follicles), can lead to premature ovarian failure (POF, exhaustion of the ovaries), which makes pregnancy more difficult. Triple X syndrome (XXX), which occurs with a frequency of 1 in 1000 women, as well as pre-mutations on the gene of the Fragile X syndrome (FMR1 gene), can also cause early ovarian insufficiency.

3.4. Environmental toxins

Environmental toxins to which we are exposed in modern everyday life – pesticides, insecticides, heavy metals such as lead, plasticizers – and which we ingest in trace amounts through food (e.g. PCBs, polychlorinated biphenyls) are another factor that can disrupt fertility. These molecules can mimic hormones in the body (“fake hormones”) and thus upset the hormonal balance.

3.5. Medication, chemotherapy for cancer

Regularly taken medications and medical drug treatments can also affect fertility. Chemotherapy and radiotherapy for cancer are a special case. How much or whether fertility is damaged by chemotherapy depends on the type and dosage of cytostatics (substances that inhibit cell growth or cell division) used in chemotherapy.

At ReproCreate, there are possibilities to still make the desire to have children come true in the event of fertility problems after chemotherapy or radiotherapy has been completed, as well as preventively before starting cancer treatment. In the case of the latter, sperm and eggs can be frozen in the clinic for later fertilization (cryopreservation).

3.6. Stress

Stress can also upset the hormonal balance and thus contribute to reduced fertility: sperm quality can be negatively affected in men and the menstrual cycle in women. This applies to stress at work or professional life, but also the stress and psychological pressure that can arise as a result of protracted futile attempts to get pregnant can have an exacerbating effect on the fertility problem. If you feel increased psychological pressure because the longed-for pregnancy does not occur or does not occur, we recommend that you seek psychological support at an early stage.