Preganancy

Well outside the fact if its not under control he could have a heart attack making the baby.

But as far as YOUR pregnancy... its a risk only if its YOU that has the diabetes.

How old are you?

Do you know anything about biology? This is pretty easy stuff to figure out.

What exactly do you think will happen if you get pregnant and your boyfriend has diabetes? Do you think he'll pass it on to you, or the baby?

I think it's time to do a bit of research, learn how the human body works, how sex works, how pregnancy works, before you go ahead with this.

This is grade 9 biology. Are you in grade 9?

preganancy

Does he have type I or type II diabetes? How long has he been a diabetic? Is it well managed?

For some couples there can be fertility problems associated with diabetes in either partner. In men it may effect the quality of the sperm and in women it may lead to early pregnancy loss.

Neither is a guarantee however, and plenty of couples, where one partner is diabetic, have healthy pregnancies and babies.
The key is well managed diabetes.

You don't mention how long you have been trying, but it might be wise for both of you to visit the doctor together to discuss your plans for pregnancy.