Have you ever used the word……

I don't think it's American, but I've only heard in medical context- most common use is "postpartum depression".

Or postnatal!

I’ve heard this word. It means postnatal, surely.

As a an old ex midwife we always used postpartum back in the 1970’s

Sadly, I connect this word with reading of the deaths of mothers after childbirth 😢

Its always been around, but, as others have said, in medical contexts

M0nica

Its always been around, but, as others have said, in medical contexts

Exactly.

It’s definitely a “medical” term and I’ve heard it used.

hollysteers

Sadly, I connect this word with reading of the deaths of mothers after childbirth 😢

No, that’s not the meaning. Not as I understand it anyway!!

The word itself doesn't imply anything bad, like death or depression, just the timing of whatever event is being described, usually in a medical context. I don't know why it has taken the place of post-natal.
I imagine you could also say "postpartum clothes buying" to describe that search for clothes to fit your new shape (and it wasn't the slender figure you'd been looking forward to returning to)

I've only heard the word in a medical context, never as a way of describing a timescale in an ordinary conversation. But then I imagine most young people look to the Internet for answers about childbirth, etc, where words like that are often used. I'm in favour of people learning as many "real" words as possible (and using them). Heaven knows, we're closing down our vocabulary at a rate of knots these days, so anything that counteracts that has to be good....

Only in the phrase postpartum hæmorrhage.