Amstaff male over a English bitch???

is it ok to put a Amstaff male over a English bitch or would this cause problems with oversized pups?

*Have moved topic to here*

The first litter i bred was Tyson (amstaf)male over english bitch, it was an accidental litter though!
She had problems delivering the pups but the vet said it wasnt the size of the pups but it was more to do with the fact that her body was still growing and changing that caused the complications.

My advice would be make sure the amstaf isnt TOO big of dog (Ty is too big to put over an english now apparantly he is full grown) and make sure the english bitch has stopped growing and has reached full maturity