Question: What of children who die in the womb or of babies and young children who die before baptism? Can we suppose that they are in heaven?
— Richard Mackin Jr., Maine
Answer: The Scriptures do not address such a matter, and God has not explicitly revealed to us the destiny of unbaptized children. But, it is generally held by the Church that children who die in the womb, or die before age seven without being baptized, do enjoy happiness with God in heaven.
Scripture does teach, “no one can enter the kingdom of God without being born of water and Spirit” (Jn 3:5), and, “Whoever believes and is baptized will be saved; whoever does not believe will be condemned” (Mk 16:16). However, such texts seem to presuppose one is able to know and personally reject these teachings. Since God is just, justice would seem to require that one be judged by what they can reasonably know. Unborn and/or very young children cannot realistically know such things, and, hence, God who is just must supply some other way for them to accept the kingdom after death. So, while we cannot have an absolutely certain answer, there is good reason to hope they are saved and with God, due to his revealed justice.
Prayer for a child who dies before baptism
God of all consolation,
searcher of mind and heart,
the faith of these parents [N. and N.] is known to you.
Comfort them with the knowledge
that the child for whom they grieve
is entrusted now to your loving care.
We ask this through Christ our Lord.