It is now believed that 1 in 6 couples struggle to conceive worldwide. Around half of these cases are caused by male infertility and half by female infertility.


Infertility is often referred to as 'subfertility' and vice versa but there is a big difference between the two. There are many reasons that people may suffer from infertility, meaning that there is 0% chance that they can have a baby naturally. For women this can range from reasons such as the menopause, to anatomical problems like blocked/missing fallopian tubes. Infertility in men most often means that they do not produce any sperm, or that the sperm that is being produced is unable to fertilise an egg.

Subfertility is much more common and can either mean that it is much more difficult for a couple to get pregnant naturally, or intervention with IVF is necessary. Women are at their most fertile around the age of 25 and as time goes on the number of eggs in the ovaries decreases as well as the quality of the eggs. More and more modern women are choosing to delay having children until later in life which is creating more demand for IVF. In 1945, around half of women aged 25 had a child. In 1965, around a quarter of women aged 25 had a child and now only around 5-10% of 25 year olds have a child.

There is a huge spectrum of causes of infertility and subfertility and frustratingly in around 15% of cases a cause cannot be found - known as unexplained infertility. It is also possible to have a baby with no difficulty and then find it impossible to have a second one - known as secondary infertility. As we learn more about the causes and complications of subfertility more answers are becoming available and more and more people are able to conceive successfully using assisted reproduction.

Read more about female infertility

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Read more about male infertility

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