In an interview on Radio New Zealand's Checkpoint programme, MrsLomu told journalist John Campbell about what she had hoped to be a happy surprise for her husband and ultimately, their family.
"I got the forms ready and we needed the blood test papers so I went and got those done. And then I said: 'Jonah, I want to help you'.''
She told the programme Lomu was excited at the news and the couple underwent testing procedures shortly before the family flew to the United Kingdom for the Rugby World Cup.
"We always said we don't want to get too excited in case compatibility wasn't an option.
"Results came back and it said that we weren't compatible.''