An American couple are looking into other methods of having children after they discovered that she was allergic to his sperm on their wedding night.

Before their wedding, the couple always used protection, but once they became as man and wife and had unprotected sex, things started to go wrong.

"Pretty much right after I knew something was not right because I was in a lot of pain," Julie reveals in an interview for a documentary called Strange Sex.

"The pain that I was feeling was inside, like somebody sticking needles up inside of me like a real painful burning. It was really scary."

Her suffering would last for weeks after the couple had sex, and sometimes blisters appeared.

Doctors were initially unable to explain the affliction, but a friend suggested that it might be an allergy and after a range of tests, the problem was diagnosed as seminal plasma hypersensitivity.

'The body recognises the sperm as a foreign protein, like it would recognise a peanut allergen or a pollen so you have swelling, you have itching, you have inflammation of the nerve endings," explains Dr Abndrew Goldstein from the University of Cincinnati Medical Centre.

It also means that Julie body attacks Mike's sperm and renders it inactive.

Doctors developed a treatment for the problem, but while it worked for some couples who suffered from the same problem, it didn't work for Mike and Julie.

The Boydes are now looking to adopt instead.