Shrinking Uterus??

My wife and i have been through 2 failed ivf cycles.  All of our #'s always come back well, good embryos etc....  Last cycle my wifes Uterus wall reached an 8 in depth.  
In looking for more answers we have recently undegone an HSG.  The dr has said that her uterus is noticiably shrunken, and he feels a surrogate would be best as she can not conceive.  This was shocking new to say the least.  The dr said he has never seen this before.  We had an HSG a year ago, they said there was significant difference.  

The dr explained that the muscles surround the uterus seem to be the problem as the have tensed, pushing on the uterus.  my wife does experince intense pain during these procedures, a year ago she had no pain during the procedure.  have you ever hear of anyting like this?