Infertility is when a couple cannot conceive (get pregnant) despite having regular unprotected sex. Around one in six or seven couples may have difficulty conceiving. This is approximately 3.5 million people. However, the number of couples who are actually infertile is low, around 5%.

Conceiving naturally 

About 85% of couples will conceive naturally within one year if they have regular unprotected sex. For every 100 couples trying to conceive naturally:

  • 20 will conceive within one month. 
  • 70 will conceive within six months.
  • 85 will conceive within one year.
  • 90 will conceive within 18 months. 
  • 95 will conceive within two years.

A couple will only be diagnosed as being infertile if they have not managed to have a baby after two years of trying. There are two types of infertility:

  • Primary infertility, where someone who has never conceived a child in the past has difficulty conceiving.
  • Secondary infertility, where a person has had one or more babies in the past, but is having difficulty conceiving again.

Deciding to seek help

Some women get pregnant very quickly but for others it can take longer. It is a good idea for a couple to visit their GP if they have not conceived after one year of trying.

Women over the age of 35, and anyone who is already aware that they may have fertility problems, should see their GP sooner. The GP may be able to check for common causes of fertility problems, and suggest treatments that could help. If fertility problems are diagnosed, there are many different treatments and procedures that are available.


For couples who have been trying to conceive for more than three years without success, the likelihood of pregnancy occurring within the next year is 25% or less.

Various treatment options are available for infertility, such as intrauterine insemination (IUI) and in-vitro fertilisation (IVF). The success rate of these treatments is 15% for IUI and 29% for IVF, and these decrease as a woman ages.


Last updated: 04 October 2011

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