Guide for Older Women
Why is age important?
Age is an important independent factor affecting female
fertility. Women are waiting longer to begin a family. Age
related decline in fertility may take place at a quicker pace than
what most women expect. This is due to age related decline in the
number and quality of eggs in the ovaries. Decline in natural
fertility accelerates after the age of 35 years and this decline is
not completely offset by assisted conception treatments. The chance
of a live birth following IVF treatment with fresh embryo transfer
varies with age. This is 32% for women below 35 years of age and
declines to 13.6% for a woman who is 40 years of age (National
What is ovarian reserve?
Women are born with a fixed number of egg containing follicles
in the ovaries. At birth this may number around 1 million. By the
onset of puberty this number would have dropped to around 300,000.
Only about 300 would be ovulated during the reproductive years and
the rest of the egg containing follicles are lost by a process
called atresia. This process of atresia is gradual and is not
offset by pregnancy or being on the contraceptive pill. This rate
of loss of egg containing follicles may vary from woman to woman.
Smoking accelerates this loss of egg containing follicles (ASRM,
2012). This decline in egg quantity is called 'loss of ovarian
reserve'. Blood tests for hormones such as follicle stimulating
hormone (FSH), Anti-mullerian hormone (AMH) and an ultrasound for
checking the antral follicle count (AFC) give an assessment of
Egg quality and advancing age
Advancing age also has an impact on egg quality. An important
reason for decline in egg quality is due to increased frequency of
genetic abnormalities in the egg with increasing age. This results
in lower success with assisted conception and an increase in
Women who are over 35 years of age should seek advice sooner
from their GP if they are finding it difficult to achieve a