Causes of infertility

Infertility is usually defined as not being able to conceive (become pregnant) after a year of trying (or after six months if you are over 35). You may be diagnosed as ‘subfertile’ if you are able to conceive naturally but have repeated miscarriages.

Being able to have a baby naturally depends on:

  • A woman being able to produce an egg from one of her ovaries
  • An egg passing along the fallopian tube
  • A man producing enough good quality sperm that can pass into the fallopian tube to fertilise an egg
  • Sexual intercourse taking place during ovulation so that the egg can be fertilised
  • Having been fertilised, the egg needs to be able to attach to the womb (uterus) so that the embryo can develop

If there are problems with any of these steps, it may be impossible to become pregnant without infertility treatment.