The question of “are you obligated to intend to try to have at least one child, if nature permits — that is, to throw NFP to the winds for a long enough period of time, and to accept a child if Our Lord wills it?” has been discussed on this forum at length, generating much heat but little light.
That’s not the standard for a valid marriage. You can argue the point, as you’ve posed it, but that’s a completely different subject. With respect to a valid marriage, the question isn’t “do you intend to try to have a child?”, but rather, “do you exclude the intention to have non-contraceptive intercourse?”
It’s the whole “open to life” question, and not a question of “planning to have a child.” A couple who practices NFP is “open to life”. A couple in which one or both spouses is sterile, and has non-contraceptive intercourse, is “open to life.”
“Trying to have a child” doesn’t come into it at all.
I have an inquiry out to the CDF in Rome on this matter
It’s pretty well-established that there’s not a requirement to try to get pregnant; only that a couple promises – by virtue of their consent exchanged at their wedding – to allow non-contraceptive intercourse. (And, to be fair, that doesn’t mean “always and every time”, either. It would be sinful when they resort to artificial conception, but if the plan on the wedding day is “the Pill for five years, and afterwards we start planning our family” is, per se, “open to life”. They’re just going about it in a way that’s somewhat sinful.)
Even if this is the case, I do think that Church teaching allows those couples for whom a pregnancy would be not impossible, but very dangerous if it happened, to avoid having children for the entire duration of the marriage.
Absolutely! They would practice NFP in their marital sexual relationship.
If “all the cards were on the table” in the pre-nuptial interview, possibly putting this wish in writing and expressly saying that it would never be used as a ground for nullity, then I can’t see how it could invalidate the marriage.
If the “cards on the table” at the pre-nup interview were “look – I intend to stay on the Pill
for the entirety of our marriage, and that’s non-negotiable”, then that would count as an “intention against children”, and would indicate defective consent. (The cleric at the interview, and celebrating the wedding, might make the prudential judgment that this isn’t a
definitive stance that they will hold for the rest of their lives, but just an expression of where their emotions / minds are
right now, and therefore, allow the wedding to proceed.)