I know a woman with BPD who has one son. She desperately wanted kids and had to try very hard to conceive. But once the kid was born, she realised she didn’t actually like being a mother. Her BPD made her unstable, and created a tense home situation, and she expressed numerous times how she wished she’d never had him, so she could have focused on her mental health instead, how having a (now teenaged) child just made it that much harder. Not once did she express any joy or happiness over having a kid.

That’s the only example I know of and obviously it’s anecdotal. I myself do not have BPD, but I don’t want kids for other reasons, which is probably why she felt more comfortable talking like that in front of me.