Male infertility is incredibly common with around 40 percent of infertility in couples being due to male factors.
What causes male subfertility and infertility?
The terms subfertility and infertility are often used interchangeably but they aren’t quite the same thing. Infertility is the inability to conceive naturally after one year of trying. Subfertility, on the other hand, is where the possibility of conceiving naturally exists, but it takes longer than average.
In about 30 to 40 percent of cases, the problem is in the testes, which are the glands that produce sperm and testosterone (the main male sex hormone). The cause may be damage to the testes from trauma or surgery (such as hernia repair surgery) or as a result of childhood infections such as mumps, or treatments for cancer such as radiation or chemotherapy.
In around 10 to 20 percent of cases, the problem is a blockage in the sperm’s path from the testes, through tubes called the vas deferens to the penis. This can be caused by scarring from an infection, a vasectomy (surgery to cut the vas deferens and prevent the passage of sperm), or cystic fibrosis. Backward movement of sperm into the bladder, instead of out through the penis, can also cause infertility.
Heat is known to affect sperm production. Heat damage may occur if one or both testes fail to descend into the scrotum. Many men have enlarged veins around the testes (known as varicocele) that may also raise the temperature in the testes. If they are very large, varicocele may cause low sperm production. Heat from strenuous exercise such as cycling can also impact sperm quality.
Less commonly, infertility results from a hormone deficiency. Luteinizing hormone (LH) and follicle-stimulating hormone (FSH) cause the testes to produce testosterone and sperm. The pituitary gland, located in the brain, makes these hormones. Any condition that lowers LH and FSH levels, such as a pituitary tumour, can result in low or no sperm production and low blood testosterone levels.
Certain inherited (genetic) diseases such as cystic fibrosis can also cause low or no sperm production or sperm that have decreased mobility.
In 30 to 40 percent of men with infertility, the cause cannot easily be found but there are environmental factors that are known to cause poor-quality sperm that we will typically investigate:
- Work: Quite often we see cases where the work environment is impacting sperm production and fertility. Extended periods of sitting are associated with decreased sperm counts usually as a result of increased testicular heat. Shift work (long, irregular working hours) has been related to infertility and also reduced sperm motility and morphology. Other causes include exposure to toxic chemicals.
- Lifestyle factors: Alcohol consumption, smoking, and recreational drug use (such as anabolic steroids, marijuana, cocaine, and methamphetamines) have all been linked to low sperm counts, erectile dysfunction, and are risk factors for infertility. However, in many (though not all) cases, this can be reversed by ceasing taking the drugs and improving overall health.
- Psychological factors: Mental health issues such as depression, anxiety, and other psychosocial factors have been linked to reproductive problems. Depressive symptoms are associated with erectile dysfunction, while anxiety has been linked to changes in hormone production, which can lead to infertility. Medication and supplements to manage mental health issues may also affect reproductive health, so it is important to understand how certain prescriptions can interfere with reproductive well-being.
- Medications: Medication and supplements may also affect reproductive health, so it is important to understand how certain prescriptions can interfere with reproductive well-being.
How is male infertility evaluated?
If you and your partner are unable to conceive after a year of trying, you should speak to your GP for a referral to one of our fertility specialists.
First, we will take a medical history. Questions will likely include your childhood growth and development and whether you have had past infections and surgeries, sexually transmitted diseases, damage to the testes, and exposure to medications or harmful chemicals.
Your doctor will do a physical exam to look for signs of low testosterone or other conditions that affect fertility (such as small or missing testes). You also will have a semen analysis (often more than one) to look at the quantity, movement, and shape of the sperm. Blood tests will look for hormone deficiency.
Your partner should have a medical history and a full evaluation done at the same time. This will give you a complete picture of your ability as a couple to have children.
How is male infertility treated?
Treatment for male infertility depends on the cause. Surgical sperm retrieval is a popular option to retrieve sperm from the testes in cases where no sperm is present in the semen (following a vasectomy, for example).
In some cases, dietary and lifestyle changes, along with medications or supplements, can improve sperm quality.
Your fertility doctor will discuss options with you, including surgery where appropriate.
If the cause is due to low testosterone, treatment with hormone injections (LH and FSH) is usually successful. However, it may take a year or longer of hormone therapy to get enough sperm production and bring back fertility.
Assisted Reproduction Technologies
Other options for a couple to achieve pregnancy include assisted reproductive technologies. Treatments include (IUI), (in vitro fertilisation or IVF), or injecting a single sperm into an egg (intracytoplasmic sperm injection)
To improve your chances of successful treatment, it is helpful to maintain a healthy lifestyle— adequate (but not strenuous) exercise, eat a healthy diet, and do not smoke or use recreational drugs.
For more information on fertility and how to prepare for pregnancy, check out our articles below