In Genesis 38:27, Psalm 48:6, Isaiah 23:4, and Revelation 12:2, this signifies to conceive and bring forth the things which pertain to spiritual life. Travail here signifies also the doctrine of the New Church and its difficult birth. (Apocalypse Revealed 535)

Travail signifies acknowledgment of the good and truth of the church in faith and act. (Arcana Coelestia 4919)

'To travail in birth' signifies conceiving and bringing forth the elements of spiritual life.