Getting older affects your fertility. This is true whether you are a man or a woman.
How age affects a woman's fertility
Women are born with all the eggs they are going to have. As you get older, your eggs get older too.
Women are most fertile in their early 20s. Your fertility starts to reduce after 30. This reduction happens faster after 35.
If you are 30, each month you try to get pregnant naturally, you will have about a 1 in 5 chance of getting pregnant. If you are 40, each month you try to get pregnant naturally, you will have less than a 1 in 20 chance of getting pregnant. You are unlikely to get pregnant naturally after age 45.
Fertility treatments such as in vitro fertilisation (IVF) do not work as well in women over 40.
How age affects a man's fertility
Men are not born with all their sperm. After you go through puberty, you make sperm every day.
Fertility may start to reduce in your mid-40s. You may start to make less sperm and your sperm quality may not be as good.
Some men may still have children when they are older. But there is growing evidence that fertility in men declines as they age.
When to see your GP about fertility problems
Fertility tests for women
You can get hormonal blood tests to check how many eggs you have. This is called your ovarian reserve.
One of these tests is the anti-Müllerian hormone (AMH) test. AMH is a hormone produced by the follicles in your ovaries. The follicles are the small sacs that eggs grow in.
The more follicles that are growing, the higher the AMH number is. This can give you an idea of how many eggs are present in your ovaries.
The AMH test does not:
- check the quality of your eggs
- predict how many eggs you have left
- detect other fertility problems such as blocked fallopian tubes
- tell you the exact number of eggs you have
This means that the AMH test can be falsely reassuring.
AMH levels can also be affected by some hormonal contraceptives. Do not delay trying to get pregnant based on a good AMH reading.
Fertility tests for men
You can have a semen analysis to check how much sperm you have and its quality. This is when a sample of your semen is analysed in a lab.
How age affects pregnancy risks and complications
If you are well and have a healthy weight for your height, you are more likely to get pregnant and have a healthy baby. But being healthy does not completely cancel out the effect of age.
Older women are at greater risk of certain complications.
These include:
- miscarriage
- pre-eclampsia
- gestational diabetes
- having a baby with a chromosomal abnormality
Chromosomal abnormality
Chromosomal abnormalities are genetic disorders.
Examples of chromosomal abnormalities include:
- Down syndrome
- Edwards' syndrome
- Patau’s syndrome
You might be offered a screening test when you are pregnant to check if your baby has a chromosomal abnormality.