Oomis,
Fair enough. I am also unsure as to whether adoption fulfills the mitzva of pru u’rvu, but that is not the issue.
I was just adding a point to Frumguy’s sentiment, that if for whatever medical reason a couple cannot naturally fulfill the mitzva of pru u’rvu, perhaps public funds would be better used elsewhere as there are many ways a couple can build a family, regardless of their fertility status.
Of course couples who can fulfill the mitzva should, I am just wondering to what extent it is necessary to fulfill the actual mitzva of pru u’rvu, or to help others fulfill it with public funds, when it is not in a couples natural capability.