Final answer:
The correct term for the decreasing length of hospital stays after low-risk vaginal births is 'early discharge.' This is part of the broader postpartum period, which lasts around 6 weeks post-childbirth as the mother's body returns to a non-pregnant state.
Step-by-step explanation:
The term used for the decreasing length of hospital stays of mothers and their babies after low-risk vaginal births is early discharge. Other terms used to describe the post-birth period are early postpartum and immediate postnatal. The postpartum period refers to the approximately 6 weeks following childbirth as the mother's body returns to a non-pregnant state.
This is significantly different from postoperative recovery, which typically refers to the recovery after surgical procedures such as a Caesarian section. Understanding these terms is important as they reflect the different recovery processes and durations that accompany different childbirth experiences.