Ok, let's calm down a bit. Everything is technically headcanon until proven by the game itself. So far, we know the following:
1. In hopes of understanding why abominations were being born from women who were never kidnapped by monsters, the local church went to Arcezon Town and convinced/pressured the people to give up their pregnant women and infants at the time. This makes me believe that the problem of human women giving birth to abominations and villages getting destroyed due to this was already a thing.
2. Looking at Arcezon Town, we can conclude that it has not suffered raids like the one we stop in the game, since there is no way it would still be there by the time Leila and Haanja arrive. Having most of their women capable of giving birth and their children taken away to never be seen again certainly explains the lack of people. Can't be sure if the women we rescue, besides the carpenter's daughter, are from Arcezon Town or used to be from some other village destroyed by the demi-humans.
3. The situation with the pregnant woman we rescue seems to point out that she knew it was a bad idea letting her lover cum inside her. Her brother did not suspect she was pregnant with an abomination until Haanja confirmed it, and it was only afterwards that he showed concern when Leila herself was pregnant. We can deduce, based on the lore for the Harbringer and what I just stated, that human births are not a thing anymore, but the townpeople still don't know the whole thing. The player knows, the Sisters realize what happened to the girl, but the people still don't know about the curse of the Otherworlder. And given point number one, the few women capable of conceiving children are probably encouraged to avoid that due to the fear that the church will take them away as well....yeah pretty fucked up situation.
4. Taking Leila's experience as an example and assuming the lover of the pregnant woman was just some random dude and not an abomination or priest with rizz and a pretty good disguise, I conclude that, regardless of the townspeople having good reasons to avoid pregnancies (avoid the church taking away their young women again), human births not being a thing until the curse is removed is the stronger argument. Unless Leila's situation is explained as an outlier and not simply part of the norm, there is not enough in the lore or dialogues in favor of human births being a possibility by the time Leila and Haanja arrive at Arcezon.