Well, I am a single mother who made the choice to keep a child born out of a toxic relationship.
I also am diagnosed BPD,DID, PTSD and Panic Disorder.
Most, however, of my illnesses stem from environment when I was a child and I think that environment plays a huge part in how we develop and whether or not we develop certain illnesses.
In thinking about this now, you are allowing yourself to get prepared. I think if you can take some time to learn as much as you can, and how you can set your child up for a good environment and situation and teach them how to cope properly, then you likely are doing the very best you can.
It's impossible to know for sure if you may or may not pass something on. But its not so much that you may pass something on, what happens is the vulnerability or genetic predisposition to develop an illness. This doesn't mean that your child will necessarily develop an illness.. its just a slight risk of it. So i think by creating the best environment you can and learning now good parenting strategies, you will be doing wonderfully by your future children.
Good luck and many hugs