Xiaobaitu: help on 485 pending H4 holder visits China

My son's Visa is H4, his 485 is pending, and he is going to visit China this Summer. We are wondering if his 485 status would be void by using H4 to come back to America, or to keep his 485 he must use AP to come back. (we worry about the AP apply time too long, so we want to have H4 visa). Thanks a lot.