No, I'm not sure you do.
Childbirth is spiritually defiling.
The Church does not teach that childbirth is "spiritually defiling". Typically, only non-virgins go through the experience of giving birth. And so typically, childbirth does not cause a woman to lose her virginity. But in the case of Mary, because Christ was conceived by the Holy Spirit, not by Joseph, therefore Mary was still a virgin when she and Joseph were looking for a room at the inn at Bethlehem. And therefore birth (as we know birth) would have caused her to lose her virginity. But Christ corrupts no one, whether in soul or body. And so in His birth He did not damage her physical integrity.
Matter bad, spirit good and Jesus never dirtied His immaculate diapers.
Actually, matter is good. And that is precisely why in His birth Christ preserved the physical integrity of His mother. It is the gnostics who don't care about matter, and thus who don't care about Mary's physical integrity.
-A8
What is wrong with a baby passing through a birth canal that would cause one to lose one's virtue?