What happens to children who die young?

Even from birth the wicked go astray; from the womb they are wayward and speak lies. Psalms 58:3

Many children die without reaching the age of accountability. There are many who die in the womb and yet there are many who die during birth. What happen to these kids and where do they go?

It is important to know that even though a child in the womb does not breathe it is alive in the mother. Therefore it has a soul and a spirit as well as a living body in the prenatal state. This, in essence makes your two questions one. What happens to children who die before they are old enough to accept Jesus as their lord and savior? Everyone needs salvation, even those too young to know it. We are all born into sin. However, those children who die prior to reaching their individual age of accountability are under the blood and saved by the blood of Christ. Remember, Jesus died for all, including the children. Children who are to young to accept Jesus, and understand what they have done, will spend eternity in heaven with God. It is very important that just as soon as your children are old enough to understand, you lead them to Christ.

Another answer where these children will spend their eternity lies in the verse

When Jesus saw this, he became angry and said, "Let the children come to me! Don't try to stop them. People who are like these little children belong to the kingdom of God. (Mark 10:14)