You’ve never heard of postnatal depression or a postnatal ward? It’s where you stay after giving birth. Maybe it’s because I recently gave birth So I know this, but again nobody has used the word postpartum with me in any part of my experience. I know In America they use the term postpartum depression For example though, Whereas UK uses “postnatal depression”. Be interesting to hear where you’ve heard postpartum, perhaps it’s just my Trust that don’t use it
From my experience, postnatal is used for postnatal ward, postnatal depression etc but when talking about how many weeks/months after birth you are I use postpartum and that's what I've seen when talking to women online too, we abbreviate to 'PP'. Both terms definitely used in UK in my experience, I think postnatal is more commonly used in the medical field