As @Matthew's answer aptly presented, Jesus was asked this very same question. His answer was simple:
For in the resurrection they neither marry, nor are given in marriage,
but are as the angels of God in heaven. (Matthew 22:30, KJV)
In the Bible, God's angels never come as male or female. They are not husbands or wives, and there are no angel babies. Angels do not marry, nor have children. Jesus is saying that in our transfigured, post-resurrection bodies, we will be like the angels in this respect.
There is a reason for this.
Throughout the sin-experiment on this earth, those who learn to rise above sin and who have obtained victory over it will be so inoculated against sin that they will never consider sinning again. As the prophet Nahum tells us:
What do ye imagine against the LORD? he will make an utter end:
affliction shall not rise up the second time. (Nahum 1:9, KJV)
Sin will never again exist.
But what would happen if we continued to have children in the New Earth? Being told that sin is bad, and knowing this from personal experience, are two vastly different things. Sin could be experimented again, by one of those who did not know any better. And, given an eternity of time, it would almost be a matter not of "if" but of "when." Sooner or later, sin would again emerge. But this must never, never happen. Therefore, the creation of "free moral agents" ceases after this sin experiment is finished.
Most who try to say marriage will continue in Heaven do so because they are addicted to the physical aspects of marriage and cannot bear the thought of giving these up. However, we are told in the Bible that the wonders of Heaven surpass our imagination. We will not even miss anything that we no longer have. It will be like discarding the worthless in favor of something of greater value than we have ever known.
But as it is written, Eye hath not seen, nor ear heard, neither have
entered into the heart of man, the things which God hath prepared for
them that love him. (1 Corinthians 2:9, KJV)
God knows what will make us happy, and is prepared to do so beyond our wildest imagination.