Could my baby's big bpd actually be dangerous to me?

What's "big bpd": Bpd stands for "bronchopulmonary dysplasia." it refers to damage sustained to a newborn's lungs, usually as a result of being born premature and requiring mechanical breathing support in a neonatal intensive care unit for a prolonged period of time. It is not contagious.

Not usually: I assume you're actually referring to head size during delivery, the diameter that will have to fit through the birth canal. It can result in failure to progress and lead to a cesarean section if your pelvis doesn't stretch, but if you are in a birthing center with that kind of ability, and your OB knows the bpd is going to be an issue, you should be fine.