Causes of Infertility

Before starting treatment, it is important to know the cause of the fertility problem. Often, there is more than one factor, so a thorough investigation of both partners is needed.

Normal Time To Conceive

It is normal for a couple having regular intercourse to take up to two years to conceive. Sometimes reassurance is all that is needed. Women who are 35 or under, should start investigations after 12 months of trying. Women over 35 years of age, with a declining egg reserve, should however start investigations after 6 months of trying.

Lifestyle Factors

Lifestyle factors contribute to a significant proportion of the infertility seen by specialists. Specifically, weight, diet, too much exercise, irregular sleep and too much stress are all common contributors.

Women’s Weight
Women who have a normal body mass index (BMI) are more likely to conceive and have a normal pregnancy than those who are either underweight or overweight. A normal BMI is 18.5 - 24.9 for non-indigenous Australians and 17.7 - 22.9 for women of Asian descent. Your BMI can easily be calculated by dividing your weight in kilograms (e.g. 65) by your height in metres, squared (e.g. 1.7 x 1.7) = 65 / (1.7 x 1.7) = BMI 22.5.

Junk Food
As little as one serving of junk food a week, for either partner, can reduce the chance of pregnancy by one third. Junk foods includes deep fried fish and chips, fast food burgers and pizzas.

Alcohol
Alcohol in moderation is not a problem while trying to conceive. Too much, however, can cause weight gain and reduced sperm function. Extreme alcohol consumption can also cause Foetal Alcohol Syndrome that may result in physical and behavioural problems for the child.

Smoking
Smoking, by either partner, halves the chance of pregnancy.

Stress
Work and life stress can wear us down and reduces the chance of pregnancy. Struggling to conceive is also very stressful. Simple coping strategies include having a hobby, taking regular gentle exercise and sharing problems with your partner, friends or family.

Disturbed Sleep
You should aim to go to bed at a regular time every night. Female shift workers, with irregular sleep patterns, have been shown to have reduced fertility and an increased rate of miscarriage.

Caffeine
There is no clear evidence that caffeine affects fertility, but some studies indicate that women who consume large amounts of caffeine take longer to conceive and may have a higher risk of miscarriage. The literature also suggests that caffeine intake, possibly through sperm DNA damage, may negatively affect male reproductive function.

Exercise
Gentle exercise is good for general health and reducing stress. However, too much cardiovascular exercise and weight training, in women trying to conceive, can reduce the chance of pregnancy and increase the risk of miscarriage. Therefore, it is best to err on the side of caution and limit exercise to walking, stretching and yoga. A large amount of high-intensity exercise in men, may also be detrimental to sperm quality and should be avoided while trying to achieve pregnancy.

Men’s Weight
Men who are overweight often have a reduction in sperm concentration and motility, reducing the chance of pregnancy. Being overweight and having a poor lifestyle also increase the risk of oxidative stress affecting the sperm. This causes sperm DNA fragmentation. Sperm DNA fragmentation is associated with both a reduced chance of pregnancy and an increased risk of miscarriage. It is also thought to be a risk factor for autism.

Work-Related Chemicals
Although rare these days, exposure to some industrial chemicals can affect reproductive health. Hairdressers in particular have reduced fertility and a higher risk of miscarriage. Many man-made products contain endocrine disrupting chemicals (EDC’s). These can have a negative effect on both female and male fertility.

We suggest you find time to watch this 10 minute video prepared by the American Society of Reproductive Medicine (ASRM).

Given the widespread nature of EDCs and strong evidence of harm, you may understandably be concerned and have questions about what you can do to control your own environment and limit exposure to EDCs. The following ‘seven safe and simple steps’ are cost effective, do not require detailed scientific expertise and will have real benefits for you:

  1. Try to use organic foods with a lower pesticide burden.

  2. Avoid canned and processed foods.

  3. Avoid handling thermal paper receipts.

  4. Know what’s in your personal care products.

  5. Limit phthalates and parabens by being careful with your plastic containers.

  6. Minimise exposure to flame retardant chemicals that are used in the manufacture of furniture, electronics and construction materials by replacing damaged furniture and appliances, buying natural products that are less flammable, and recirculating indoor air.

  7. Avoid non-stick cooking pans to prevent PFAS (Perfluoroalkyl & Polyfluoroalkyl Substances) exposure.

Physiological Factors

Ovulation Problems
One of the most common causes of infertility is irregular or no ovulation. A normal ovulatory cycle is usually 28 days long. If the cycle is greater than 35 days, there is a possibility that ovulation is not occurring in some cycles. An irregular cycle can make the timing of intercourse difficult. The most common cause of ovulation problems is polycystic ovarian syndrome (PCOS).

Endometriosis
A third of women have endometriosis. This occurs when endometrial cells, that usually line the inside of the uterus, grow outside the uterus. In endometriosis, these ectopic (in an abnormal place) endometrial cells can be found on the membranes (peritoneum) lining the cavity of the abdomen and covering the pelvic organs. Endometriosis is most commonly seen on the ovaries, pelvic side wall, the large bowel and the bladder.

The most common symptoms are cramps, back ache or pain in the legs. In patients with endometriosis, these symptoms usually occur 2 - 3 days before the period starts. Less common symptoms include deep pain during intercourse, bladder pain and sharp pain when opening the bowels.

Problems with having intercourse
Both women and men can have psychological or physical factors that prevent effective intercourse. Some women struggle with penetration due to a condition called vaginismus. Some men find it difficult to achieve an adequate erection to have intercourse. There are a variety of causes.

Blocked Fallopian Tubes
The fallopian tubes transport the egg, sperm and the pre-implantation embryo into the uterus. Blockage of the tube will disrupt this transport. The most common causes of blocked fallopian tubes are sexually transmitted infections such as chlamydia or gonorrhoea, and endometriosis.

Fibroids
Fibroids are common. They are a benign (non-cancerous) growth in the smooth muscle, which form the walls of the uterus. Fibroids can negatively affect fertility if they encroach on the uterine cavity or if they are large (>5cm). Small fibroids usually have little or no effect.

Polyps
Polyps are benign growths, forming finger-like projections from the lining of the uterus. Spotting between periods and heavy periods can be a symptom of polyps.

Adhesions
Adhesions are caused by scar tissue. They can result from trauma at the time of surgery or a pelvic infection. Adhesions can affect the tubes and ovaries. They can also occur inside the uterine cavity.

Sperm Problems
Sperm problems are common. The number of sperm (concentration), the forward movement of the sperm (motility) and the physical structure of the sperm (morphology) can all be suboptimal, reducing the chance of fertilisation. Sometimes these are unexplained. In other men, they are due to poor lifestyle or genetic problems.

Some men have no sperm found at their initial sperm test. This is known as azoospermia. Having this finding can be very distressing. Fortunately, in most cases, sperm is still present in the testicles and can be retrieved with a surgical biopsy. The absence of sperm in ejaculated semen may be due to very low sperm production in the testicles or due to an obstruction to the outflow of the sperm. Complete absence of sperm production is fortunately very rare.

Some men produce antibodies that bind to their own sperm. These antibodies can affect the transport of sperm to the site of fertilisation and the binding of the sperm and egg.

Another common problem is sperm DNA fragmentation, a term used to reflect the extent to which the chromatin, which is the complex of DNA and protein within sperm, is damaged. DNA fragmentation is thought to be due primarily to oxidative stress. Common causes are poor lifestyle, advanced age, too infrequent intercourse or chronic medical conditions. Some medications such as treatments for high blood pressure can also make it worse.

For more information, please email the Minerva Fertility IVF Nurses at nurse@minervafertility.com.au or call us on +61 2 8883 3319