In his article "An unbaptised baby may never see God face to face in heaven" (August AD2000), John Young gives a rather pessimistic view of the Catholic Church's teaching with regard to the fate of those infants who die before having been baptised. He quotes from several sources, including the Catechism of the Catholic Church: "The Church does not know of any means other than Baptism that assures entry into eternal beatitudes".
That here a "Baptism with water" is meant can be deduced from another sentence in the same article (1257): "Baptism is necessary for salvation for those to whom the Gospel has been proclaimed and who have had the possibility of asking for this sacrament".
This clearly means that those to whom, through no fault of their own, the Gospel has never been proclaimed, cannot be held responsible for not having asked for the sacrament of baptism with water. This must be the reason why the Compendium of the Catechism, article 262, states that "all those who, even without knowing Christ and the Church, still (under the impulse of grace) sincerely seek God and strive to do his will can also be saved through a Baptism of desire".
As infants, including aborted fetuses, have never had the opportunity to ask for a Baptism with water, it would be illogical to assume that Our Lord, in His mercy, would not give an infant the same possibility "under the impulse of grace" of asking for a Baptism of desire as He would give to an adult, the more so since they have never committed a personal sin.
Hong Kong, China