Diane makes a good point regarding the stallion lines - just because your beautiful boy is lghter in build, he still carries the normal heavier boned lines behind in his breeding. and can easily throw these into any future foals. Also, as you are obviously a very caring owner, I feel that if you let this pregnancy go ahead you are going to spend the next year stressing about whether you have done the right thing or not, and the stress levels are just going to rise as the foaling date gets nearer - not something that i would want to put myself through as any 'normal' breeding is stressful enough!