Both Mac downloads are broken too. However, because neither is the correct size (646MB vs. 2GB & 619MB vs. 750MB), I think it's an itch.io server problem.
(This was my workaround before I bought the Mac version of RPGMaker MV.)
If you have a known working Mac version of any other MV game, you can replace the assets in the app.nw folder (Mac) with the assets from the www folder (BS9).
I already mentioned a possible post-birth sprite update in an earlier thread, but would it be difficult to have dedicated nekkid & gravid Gestational Pool sprites?