Good question. This could lead to some interesting discussions. Off the top of my head I don't recall an exact answer in the Bible. It may be one of those mysteries that will be answered when we meet Him face to face and all mysteries will be revealed.
It says that we will be like the angels. Notice I said like them, we will never be an angel.
In my personal opinion for what it is worth (probably not much) I don't believe there will be births or children in heaven.
Heavenly beings do not die and therefore do not need to reproduce the way we do. Marriage is part of God's plan for humanity while living in this motal frame but will have no useful purpose we we receive glorified bodies.