A woman who was told her tissue was too similar to her husband's had to be made allergic to his sperm to have a successful pregnancy.

After four miscarriages, Kathryn Berrisford, from Whatstandwell, Derbyshire, was injected with her partner Joss's white blood cells, which caused her body to recognise his sperm as a foreign body.

The leukocyte immunotherapy treatment allowed her eggs to fertilise and her first baby was born in 2005.

Mrs Berrisford, who is a fertility lab manager, said it was a very rare cause of miscarriage and women were only tested for it if other reasons for miscarrying had been ruled out.

The 47-year-old said she now wanted to let would-be parents in the same situation know there was treatment available.