First, if God has middle knowledge (knowledge of what would occur in any circumstance, in addition to knowledge of what in fact does and will occur), then he could perfectly judge the infant based on his knowledge of whether the infant would have chosen God or not. But the infant’s abortion would still be a vice, given that it precludes many counterfactual virtues that could have resulted from a life lived out (such as positively influencing and being loved by others).

Second, the intrinsic value of choosing to love God (or not) is lost when a baby is aborted. Consider Luke 15, the parable of the lost sheep, the lost coin, and the prodigal son, the conclusions of which are captured in v.7:

I tell you that in the same way there will be more rejoicing in heaven over one sinner who repents than over ninety-nine righteous persons who do not need to repent.

After all, the reason God created us was so that we could choose to love and worship him. Abortion essentially rapes that freedom. “If it is better for infants to have chosen God than not” you might object, “then isn’t it immoral for God to bring infants into heaven when they didn’t choose it?” No for two reasons. First, see the possibility of middle knowledge above. Second, given that the infant has no choice, God graciously extends the morally preferable alternative to infants.