Stem cell technology is still in it's infancy.
HERE IS A GOOD ARTICLE FROM THE BBC ON THIS.
AND HERE IS A LINK FROM A FORUM, HARDLY SCIENTIFIC, BUT SEE THE FIRST COMMENT FROM A PLASTIC SURGEON... IT'S NEW, IT'S UNPROVEN IN COMPARISON WITH THE TRADITIONAL AUGMENTATION METHODS.
AND HERE IS THE MOST CONVINCING LINK... FROM THE AMERICAN ACADEMY OF PLASTIC SURGEONS.... TOO EARLY YET TO RECOMMEND.
If your wife were my patient or friend I would recommend the traditional augmentation surgery or would wait a few years for the data to point one way or the other regarding the stem cell option.
I am standing by if you have questions about my answer.
Positive feedback always appreciated.