"For until the law sin was in the world: but sin is not imputed when there is no law(of which one is not morally in cognizant)" (Rom. 5:13; my superscripted interpretation).
The newborn infant is not yet self-aware, hence not morally in cognizant. But when reaction to the word "NO" comes, then comes cognizance, eh?
Well, there is an age of accountability,
For before the child shall know to refuse the evil, and choose the good, the land that thou abhorrest shall be forsaken of both her kings. (Isaiah 7:16)
Moreover your little ones, which ye said should be a prey, and your children, which in that day had no knowledge between good and evil, they shall go in thither, and unto them will I give it, and they shall possess it. (Deuteronomy 1:39)
As in giving $, "it is accepted according to that a man hath, and not according to that he hath not," (2 Corinthians 8:12) accountability is according to light and grace given, which is why concerning those who were given light and grace via the apostle's preaching and healing, "it shall be more tolerable in that day for Sodom, than for that city. (Luke 10:12)
For "we are sure that the judgment of God is according to truth," (Romans 2:2) with those who know and do not do being judged more harshly. "But he that knew not, and did commit things worthy of stripes, shall be beaten with few stripes. For unto whomsoever much is given, of him shall be much required: and to whom men have committed much, of him they will ask the more." (Luke 12:48)
And if those who are ignorant see less punishment, having less light they disobeyed, those who are not only ignorant of what is lawful vs sinful, but do not even have any ability to morally reason, and feel no guilt, can hardly be condemned based on what Adam did and the nature they inherited.
Yet as unclean by nature it seems they must be redeemed by Christ on His account. I see no "sacrament" for this, and requiring baptism for them would at least exclude tge aborted, but I presume that the same Christ who admonished, "Suffer little children [paidion] to come unto me, and forbid them not: for of such is the kingdom of God, (Luke 18:16) makes these innocents accepted in the Beloved. Speculative theology.
However, baptism represents the faith choice made in conversion, being buried as one who die, and raised to walk in newness of life.