Pregnancy is rarely done well in NTR overall, never mind a niche subset of the genre, and the games that do have it are generally poor.
For example, as you're aware Atelier routinely relies on the netorase gone bad trope, and the games generally aren't good to begin with even without the "netorase" caveat. The good netorase titles (
Swapping Party,
Koibito Swapping, Marina 1-2, etc.) don't use this theme. They sometimes make good brainless smut like
Suki Datta Toshishita Osananajimi, but that's about all you can expect from the imprint.
Most games in this vein will have impregnation as an ending. As a more substantial presence, these are off-hand, maybe 1 of them will be new for you:
- [NT:Ripper] To Be At Your Side: Beloved Wife Inseminated [Eng] - Conception theme, good overall and strongly recommended.
- Didn't check Mega for link availability, but search for "NT:Ripper" and "To Be At Your Side" if unavailable -- the translation is slightly obscure due to some shota content.
- [Past Gadget] Akizuki-ke [Jpn] - Surrogate theme, unimaginative albeit good. Recommended.
- [Shrine's Gate] Fuufu Koukan [Eng, if it's still around] - Mentioned in prior post: decent and worth playing, but extremely short. Swapping with netorase undercurrent, recommended.
- [Suzuya] For the Kingdom [Eng] - Impregnation by king, remotely voyeur on heroine using magical tool to progress CGs. Lots of battles -- use Cheat Engine (applicable to Suzuya in general) -- but some nice scenes. Recommended. Unrelated:
- A Story About Stolen Lover [Eng] is their best game and highly recommended.
- Knight Whore [Eng] is acclaimed but I lost interest due to the prostitution angle.
- Being Kidnapped by Aliens [Eng] references various titles and seemed promising, but I (unintentionally) never finished it.
- Some of their other content like Ruby and Claude jumped the shark by not focusing enough on ero, thus I don't recommend. They're not "bad" but they become overly serious, even though pregnancy plays a factor in Ruby & Claude, Fairy Miracle Fantasy...
- Potato God has left a review on each of their titles. You've probably seen them, but if not, just go through his posts for extremely detailed break downs of each title.
- [Tail Aki] Yuganda Yokubou - Netorase Tsuma Shelly [Eng] - Tavern/inn setting, a mostly mediocre / average game but fits the theme.
- Unrelated: their NTR (not netorase) game Karma Rain was pretty decent and recommended.
- [Orcsoft] Kagachi-sama [Eng] - Decent though I wouldn't exactly call it particularly good (self-evident upon replay). Even though it's ending specific, the core game very much touches on the topic, obviously.
- Doujin Circle Gyu games are more corruption than anything else, but I enjoyed Sword Princess Cistina and Treasure Hunter Mai. Both have translation / MTL out there somewhere, and impregnation is a theme to some extent. Just don't touch Knights of Messiah -- that was a buggy mess, and a bad game otherwise to boot.
- [Pin-Point] Tsuma ga Kakushiteita Video [Eng] - Never got too interested in the title so I ended up dropping it inadvertently; should have presence, but I don't know off-hand if it's strictly as an ending.
- [UnderMoon] Ojou-sama wa Gakuen [Jpn] - The game seemed extremely boring so I never got too far into it, but maybe you have different feelings. Should have pregnancy, but don't remember if it's a core theme or simply as a bad ending or two.
I'm probably forgetting obvious titles, especially RPG Maker games, but as mentioned this combination is relatively sparse.
If you aren't too stressed about netorase turning into NTR and for some reason have punted it, then
Kabe 1 [Eng] was excellent and has several endings, including pregnancy and a few netorase ones. It's one of a handful of Anim titles that I actually finished end-to-end.
I have a game also in the making, but my PC is sweating a bit too much when rendering animations, so I put it on hold for a bit.
Shine