Age and trying for a baby

If you are trying to have a baby, what age you are can affect your chances of getting pregnant.

Getting older affects your fertility. This is true whether you are a man or a women.

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 at their most fertile in their early twenties. Your fertility starts to reduce after the age of 30. This reduction happens faster after the age of 35, but you can still get pregnant.

In Ireland, many women have their first babies in their thirties.

By the age of 40, your fertility is much lower than it was in your twenties. Fertility treatments don’t always work as well in women over the age of 40.

How age affects a man's fertility

Unlike women, men are not born with all their sperm. After you go through puberty, you produce or make sperm every day. Your fertility will start to reduce in your mid-40s if you are a man.

Around this time, you may start to produce less sperm. The quality of the sperm you produce may not be as good as when you were younger.

When to get medical help

See your GP if:

  • you're a woman aged over 35 and you have been trying to get pregnant for over 6 months
  • you are worried about your fertility for any reason

Fertility blood tests for women

Some private laboratories offer hormonal blood tests to check your ‘ovarian reserve’. Your ovarian reserve is the number of eggs you currently have. This can help tell you if your egg number is likely to be normal or low.

One of these tests is the AMH (anti-Müllerian hormone) test. AMH is a hormone produced by the follicles in your ovaries. The follicles are the small sacs that eggs grow in.

Your levels of AMH can be measured in your blood. This test can give an idea of how many eggs are present in your ovaries. The more follicles that are growing, the higher the AMH number is.

The AMH test does not:

  • check the quality of your eggs
  • predict your future ovarian reserve
  • detect other fertility problems, like blocked fallopian tubes
  • tell you the exact number of eggs you have

This means that the AMH test can be falsely reassuring. It is important not to delay trying to get pregnant based on one good AMH reading.

The AMH test can be expensive. You should only get it done if a fertility specialist or a GP with a special interest in fertility tells you to.

The AMH test can help fertility specialists to plan the right course of treatment for you.

How age affects pregnancy risks and complications

If you are in good health and of normal weight, you are more likely to get pregnant and have a healthy baby. But being healthy does not completely cancel out the effect of age.

The older a woman is, the greater the risk of certain complications including:

Chromosomal abnormalities

Older women have a higher risk of having a baby with a chromosomal abnormality. Chromosomal abnormalities are genetic disorders.

Down syndrome is an example of a chromosomal abnormality.

If 1,000 woman aged 30 have a baby, 1 baby will have Down syndrome, the other 999 babies will not.

If 1,000 woman aged 40 have a baby, 12 will have Down syndrome, the other 988 babies will not.

Other examples of chromosomal abnormalities include Edwards and Patau’s syndromes. You might be offered a screening test when pregnant to check if your baby has a chromosomal problems.

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This project has received funding from the Government of Ireland’s Sláintecare Integration Fund 2019 under Grant Agreement Number 123.

Page last reviewed: 15 May 2019
Next review due: 15 May 2022