The 1/6 number is made up. Here's an example source: https://www.who.int/news/item/04-04-2023-1-in-6-people-globa...
The first red flag is they use the Newspeak "experience infertility".
If you look at the data sources, they're calling women (and men) with children "infertile": https://www.cdc.gov/nchs/nsfg/key_statistics/i-keystat.htm
Obviously there's a sense in which a woman who's had children and now can't is "infertile" (though FAR more than one-sixth of women experience menopause). But it's not the sense being used by you and your parent commenter in this thread.