Painting: Michaelangelo's Prophet Isaiah
We are all familiar with Isaiah's well known prophecy of Christmas:
“Therefore the Lord himself shall give you a sign. Behold a Virgin shall conceive, and bear a Son and his name shall be called Emmanuel.” (Isaiah 7:14)
However, Isaiah made another (lesser known) prophecy of Christmas:
"Before she travailed, she brought forth; before her pain came, she was delivered of a Manchild" (Isa 66:7)
This verse is the basis for the Catholic teaching that Mary experienced no pain when she delivered Christ at Bethlehem. The Roman Catechism teaches that Christ passed through her "as sunlight passes through glass."
The reason for this is that Mary is the New Eve who gives birth to the promised Savior (see Gen 3:15). As New Eve, the Blessed Virgin Mary escapes the curse of Eve - labor pains.
This might be something interesting to discuss this Christmas with family or below in the comments. Keep in mind that all the Church Fathers before AD 600 believed that Mary's delivery was painless.