@Kari2653 This doesn't make sense to me. If they're not choosing to have the baby at the hospital, why do they need an Airbnb near the hospital? If they want a home birth, why aren't they doing it at home?
Your gorgeous listing does look like a clean and calming space, and perhaps these guests aren't fortunate enough to live somewhere as comfortable. And maybe they just want to have a hospital nearby as a backup option if there are complications. But their maneuver smells like a bait-and-switch, and I'm not inclined to take them at face value. Also, if the baby comes earlier than the projected due date, they're probably going to insist on a refund. So personally, I'd tell the guests that the space is not suited to their unique needs and advise them to cancel. Airbnb might grant a neutral cancellation as well, if a guest's intended use for the home amounts to a medical procedure.
But perhaps there are some hosts out there who have had awesome experiences with facilitating childbirths. I've heard of many weird uses of Airbnb rentals, but this is a new one to me.