What does it mean to be "pro-family"? The term is vague and contested. I suggest a philosophical definition: being pro-family means acknowledging the legitimacy of enforceable parental obligations. This means accepting that both biological parents have a positive obligation to raise their child to the self-sufficiency of adulthood.
The obligation of parents arises from the voluntary act of making their gametes available for fusion, either through sex or through assisted reproductive technology. This generates an obligation because one is responsible for the reasonably foreseeable consequences of one's actions (even if those consequences were not desired). A foreseeable consequence of making your gametes available for fusion is that you bring about the circumstance that a child is in a state of peril. Parents are obliged to get the child out of peril as a matter of justice, not just personal virtue.
Here are some logical consequences that follow from this principle:
- Both the mother and father are jointly and severally liable for their obligation.
- Both parents have obligations to every embryo that they allow to be created from their gametes.
- Neither parent can legitimately deprive the child of the protection of the other parent, since it is the child that has the claim on both.
- Neither parent can legitimately give up their parental obligation (although they may be able to delegate it in some circumstances).
Given these logical consequences, meeting their parental obligations requires the biological mother and father to raise the child together. So being "pro-family" means supporting the idea that both a mother and a father raise their children. Practically, this almost always requires them doing so together in one household, in a so-called "traditional" family.
Pronatalism is not the same as pro-family
On this definition, being pro-family is not the same as being pronatalist. A deadbeat dad with 10 kids by different women all over the place could qualify as a pronatalist, but not pro-family. A sperm donor whose gametes are used to create 100 babies would also qualify as a pronatalist, but his actions are not pro-family since he is not fulfilling his parental obligations.
Given the distinction between being pronatalist and pro-family as defined here, one can be pro-family without choosing to have children oneself. To be pro-family means to affirm that those who create children must fulfil their obligations. It does not mean that one must choose to have children in the first place in order to be pro-family.