Does size matter?

Question
I've a 18" Samoyed bitch that I am hoping to mate this year.  There is a potential mate, and as he is in a different country we would be using AI, however he is 23.5".  My bitch is on the bottom end of the breed standard here.  The dog is over the height standard for this country, but not the US standard.  Her line could use a bit more height, which we are breeding for.  
However, my main concern is for her health in carrying the pups.  I'm trying to sort out old wives' tales, about big and small pups in the womb, crushing or causing deformities.
So, would putting a dog that size to a bitch her size spell a recipe for disaster in my bitch carrying and delivering the litter?
Thank you.

Answer
Hi Marri.  My rule of thumb is to never breed a female dog to a male dog that is 5 lbs or more heaver than her.

X-rays and or an abdominal ultrasound can assist your vet in determining your dog's pelvic conformation and help in the determination if she can deliver the puppies naturally or if a C-Section will be required.

Good luck, and please do not hesitate to contact me if you have additional questions.  I also want to apologize for the delay in replying to your question.  I am having some remodel work done at my home and lost my internet connection.  It should now be working again without further delay.

Sincerely,
Penny Diloreto
www.puppies-dot-com.com