I finally got around to testing this and it does work as I thought. Click the 'i.redd.it' link on each of my posts and you'll be brought to a reddit page where you can view the original post. You can get the OP from there.
!nsfw_pregnant
NSFW pics/gifs/vids of pregnant women
Clothed 👍
Naked 👍
Pregnant sex 👍
No art please 🚫