Age and Fertility

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 onwards 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.

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.


Although there is currently no treatment to improve the quantity of eggs or reverse the effects of aging on fertility, the good news is that with advances in reproductive technology there are options to help improve a woman’s chances of conceiving including IVF treatment, pre-implantation genetic testing to test embryos for chromosomal abnormalities or fertility preservation to store unfertilised eggs or sperm.

Read more about fertility tests...