I've told friends and it's been fine. I've told lovers and it's been fine. Hell I have a couple friends I learned also have pregnancy fetishes. But at not point was it me 'introducing' them to the fetish. They either have the fetish or they don't.

That'd be like trying to convert a straight person to being gay. It just doesn't really work.

I revealed my pregnancy fetish to my all time best friend a few years ago, it hasn't effected our friendship at all.
But I think it's generally not a good idea to share your fetish with others, unless there's a good specific reason they need to know about, or if it's your partner/wife. Don't expect other people to like your fetishes & you cant really force them to like it either.

I just want my friends to not prejudge me for the fact I love the sight of pregnancy, they may not agree, but most people in their right mind find pregnancy to not be a problem to look at. I had a few friends in life who had been pregnant or their partners were, and over the years, they realized I have an adoration and admiration for pregnancy, and they are tolerant or accepting about it. All I say is there's a beauty in something of a mother to be is about to have her child. I don't force any of them to have my fetish, it's about not shaming me for my POV of a pregnant person's state of being, and I won't be surprise a friend may be in agreement not about being turned on (or maybe they are), I want others to not disapprove of me for my likes.