What should I do to fulfill a vow I made for righteous offspring, and my wife is pregnant, but I don't remember its details, whether it was a sacrifice or giving money, and what its amount was if it was money, and am I obligated to fulfill it now or after my wife gives birth?

A forgotten vow is expiated by an oath of atonement (kaffarat yamin), and this is the opinion of the majority of scholars. If the amount of the vowed money is forgotten, it has a different ruling. If the vow is conditional on two conditions, it is not obligatory to fulfill it unless both conditions are met, unless the intention was to make the vow conditional upon the mere fulfillment of the first condition, in which case the intention is effective in the vow.