Reasonable prenup agreements

I realize context does matter a lot, but I have been thinking lately about what terms in such an agreement are and are not reasonable. I have communicated to my partner that if we were to get married, I’d support a prenup because I think it’s good to be on the same page about finances and ownership, even if the relationship doesn’t end in divorce. It’s also a test - since if he suggested something one sided, then I’d rather know sooner than later.

To first order, if children aren’t involved and both partners have careers and aren’t in poverty, I’d think that two partners are entitled to their assets prior to entering the relationship, and then assets during the relationship are split equitably throughout the relationship. If I did get pregnant and had children, then I’d feel entitled to more compensation. I would personally never give up my career, but if I were to do that, then I’d feel entitled to even more. And if I were doing more household chores and labor than my husband, then I’d definitely feel entitled to more (though this isn’t the case in my relationship as my partner is an excellent cook and he does a lot of the cleaning).

Anyway I don’t quite know how to assign monetary value to the process of going through pregnancy and carrying a child (outside of healthcare expenses). I wanted to ask opinions from others who have been through this or thought it through more than I have.