In general I think payment processor are not required to associate with anybody. The government (in the US at least) is limited in their ability to prevent you

In general I think payment processor are not required to associate with anybody. The government (in the US at least) is limited in their ability to prevent you from buying guns and making porn (a form of speech), but they can’t make people do the transactions with you; the right to have somebody process payments for you is not constitutionally protected. But I’d be at least curious (as a non-lawyer) if there could be issues around discriminating against pregnant women in the US, since abortion is a service that is only used by them.