The bible says that when we sin we become guilty souls and are subject to the prescribed penalty under God's law.
Eze 18:4 Behold, all souls are mine; as the soul of the father, so also the soul of the son is mine: the soul that sinneth, it shall die.
Rev 20:14 And death and hell were cast into the lake of fire. This is the second death.
15 And whosoever was not found written in the book of life was cast into the lake of fire.
God gave us an opportunity to have our guilt transferred to Christ.
Isaiah 53: 6 All we like sheep have gone astray; we have turned every one to his own way; and the LORD hath laid on him the iniquity of us all.
So if we put our trust in Jesus we can escape the prescribed punishment.
Joh 11:26 And whosoever liveth and believeth in me shall never die. Believest thou this?
As for aborted fetuses or small children. We are born in a state of innocence. In other words, there will come a time in each of our lives when our sin consciousness will be awakened. You notice how a two year old can take a piece of candy from the shelf in a convenient store, and put in in his pocket as tho he had done no wrong? Well that is because the concept of right and wrong must be developed in each of us. Where there is no understanding of wrong there can be no guilt.
James 4:17 Therefore to him who knows to do good, and does not do it, to him it is sin.
So aborted fetuses and even small children are not guilty where the concept of sin is not developed. So according to that aborted babies and small children which are not "sin conscious" will go to heaven without the need for salvation. They are already innocent.