How could my spouses blood type affect my future child?

Jaundice. If you have type o or negative blood, and your spouse is different, your child could be born with type a or b, or rh pos blood. If that happens, there could be an antibody reaction at birth. However, hospitals test for that, and if it's noted there's a difference, they look for jaundice and treat it if seen. Truthfully, as it's caught early, it's not that big a deal anymore.