Infertility Explained | IVF Treatment | Monash IVF Australia

Infertility Explained

With today’s busy lifestyles, many couples plan carefully to ensure the time is just right to achieve pregnancy and start a family.

For the vast majority of couples pregnancy occurs naturally within 12 months of trying to conceive. However, for up to 20 per cent of couples it is a different story, they keep trying and nothing happens or they achieve pregnancy only to miscarry.

Infertility is defined as the inability to conceive after a year of unprotected intercourse, or the inability to carry pregnancies to a live birth.

There are many possible causes of infertility among males and females:

  • 30% of infertility is due to female factors alone
  • 30% of infertility is due to male factors alone
  • 30% of infertility is due to both female and male factors
  • Up to 10% of infertility remains unexplained

There may also be male or female genetic factors that affect an embryo’s ability to develop causing infertility or repeated miscarriage. In some cases, genetic factors may not prevent pregnancy and birth, but the child may have disabilities such as Down syndrome.


The main causes of infertility for females may include:

  • Blocked or damaged fallopian tubes;
  • Ovulatory problems;
  • Hormonal disorders;
  • A condition known as Polycystic Ovary Syndrome, PCOS;
  • Endometrioses;
  • Being overweight or underweight; or
  • Being over 38, from which age fertility declines rapidly.

The affects of age on female fertility

As women are born with all the eggs they will ever produce, age becomes an issue. Female fertility declines slightly at 30 years and there is a significant decline around 37 to 38 years of age. By the time a woman is 40 years old her fertility is a quarter of when she was 30. The miscarriage rate increases with age from about one in seven for women aged less than 25 years to about one in two at 40 years of age.



Male infertility accounts for approximately 30% of all cases of infertility

The main causes for male infertility include:

  • Sperm not being produced in sufficient numbers, or not at all (Azoospermia);
  • Sperm being obstructed from ejaculation;
  • Sperm that don’t swim very well in the female reproductive system restricting its ability to reach and fertilise an egg; or
  • Oxidative stress resulting from injury, infection or smoking causing semen defects.


The condition in which no sperm are present in the ejaculate is called azoospermia.

There are various causes of azoospermia which include:

  • Genetic abnormality
  • Failure of sperm production
  • Following a vasectomy

Blood tests to investigate hormone levels (FSH) may be required. A testicular biopsy may be required to confirm that sperm production is occurring.

Genetic Factors

Certain genetic conditions can affect fertility including:

  • Klinefelter Syndrome
  • Turners Syndrome
  • Cystic Fibrosis
  • Translocations
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