There are all kinds of passages where babies in the womb are mentioned in the bible. I went looking for the visitation passage, and stumbled on this one, where Jesus refers to "the children within you" in Luke 19.
The Visitation:
Recall that ministry of John the Baptist, to proclaim the coming of Jesus Christ, began while he was still in the womb, as told in Luke 1:
"And it came to pass, that, when Elisabeth heard the salutation of Mary, the babe leaped in her womb; and Elisabeth was filled with the Holy Ghost:
And she spake out with a loud voice, and said, Blessed art thou among women, and blessed is the fruit of thy womb.
And whence is this to me, that the mother of my Lord should come to me?
For, lo, as soon as the voice of thy salutation sounded in mine ears, the babe leaped in my womb for joy."
The babe leaping in the womb for joy is John the Baptist...his first proclamation that the Messiah, also in the womb, had come to the world.
There is the famous passage where God said "Before I formed you in the womb I knew you, before you were born I set you apart."
Also, realize that the Bible gets its legitimacy from the Church, and not the other way around. The Church compiled the Bible. If the Church had no authority to proclaim doctrine, then the bible is just a bunch of chicken scratch. The Bible is just scriptural tradition. There is other tradition as well, and together, they make up Catholic Doctrine. So, we don't need to find Jesus saying something to know what is Catholic (or what was Christian for 1500 years, until Luther came along).
Granted, all this only speaks to whether Catholics can pretend that abortion is moral (which they cannot legitimately do). The above says nothing about whether abortion laws are proper under our system of government. For that, you have to consider that we generally only allow consequential laws (laws to stop aggression, to prevent victimization), and the abortion laws are consequential in that they do protect a victim, so they are justifiable with purely secular and legal reasoning.