Age and Fertility

  • Reading time:3 mins read
  • Post last modified:March 15, 2024
  • Post category:IVF

The single most important factor influencing a woman’s chance of conceiving is age. Once 36, a woman’s chance of conceiving naturally is halved compared to that of a woman who is 20 years of age. When a woman is 41, the chance of conceiving naturally falls to just 4% each month.

Why does age matter?

Women are born with a finite number  of eggs, and from that moment on-wards the number and quality of eggs is declining all the time until women go through menopause at around 50-51.

The number of eggs may be even lower if there is a family history of premature menopause, or need to undertake chemotherapy or radiotherapy. Chromosomal errors also occur more frequently with age, resulting in more abnormal embryos that may not implant, or that result in early pregnancy loss.

While the effect of age on a man’s fertility is not as significant as it is with women, there is a decline in the quality of sperm after the age of 45. After this age, men have higher rates of fertility complications as their sperm volume, motility and morphology (shape) declines and the likelihood of damage or breaks to the sperm DNA increases.

The effect of age therefore not only increases the length of time it takes to fall pregnant, but also increases the risk of complications.

Complications associated with age

As you get older, your cells start to divide abnormally and may distribute unequal amounts of genetic material – causing an increased chance of genetic abnormality. Unfortunately, this means that for older women it’s not just more difficult to fall pregnant, there is also a greater risk of miscarriage, and of giving birth to a baby with a genetic abnormality such as Down’s Syndrome. There are also greater risks associated with the pregnancy and delivery.

For older men higher levels of sperm DNA fragmentation (genetic material) may mean it is more difficult for the sperm to fertilise the egg.

Assisted conception

The good news is that advances in reproductive technology, including IVF and other forms of assisted conception, can improve chances of conceiving and carrying a child.


If you use IVF or any other assisted reproductive technology, you can increase your chances of falling pregnant sooner.

Genetic testing

Pre-implantation Genetic Testing (PGT) is a method of testing embryos for specific genetic and chromosomal abnormalities before implantation. We can also select the embryo with the greatest chance of pregnancy success.

Fertility preservation

For people who are not in a position to become pregnant right now, or whose fertility is at risk due to serious illness, fertility preservation offers the possibility of having a family in the future by storing unfertilised eggs or  sperm.