In short just "forties"

Some of people call it "The Sacred Window" " , "postpartum" and hence there is nourishment postpartum.
https://nancylucina.com/nourishing-postpartum-40-day-sacred-...
https://www.incultureparent.com/closer-to-god-the-first-40-d...

in Turkish tradition "Forty-day precautions" or "making the forties" or "falling forties"
http://www.turkishculture.org/lifestyles/ceremonies/birth-21...

Hispanic : Cuarentena "Cuarentena is a period of approximately 40 days"
https://www.babycenter.com/0_bringing-back-the-hispanic-trad...

Asian: "How Long Do Post-Birth Confinement Periods Last?"
https://www.tianweisignature.com/how-long-do-post-birth-conf...

In Greece , to avoid the evil eyes :
blogs.transparent.com/greek/when-a-baby-is-born/

So finally :
just " the forties"
and in China just the thirties.

Hope it is useful.
Good Luck !