Head is bigger means your cervix has to dilate big enough for the head to come out assuming natural birth. And sometimes maybe need episiotomy by gynae to help widen the vagina for the head to come out smoothly. So just be prepared for these scenarios. But if you’re going for c sect then I don’t think the size of head makes a difference. So you may want to reduce your possibility of suffering by choosing to take epidural as early as possible if doing natural birth.