'Birth pains' in the Bible

My children, for whom I am having birth pains again, until Christ is formed in you!

For it is written, "Rejoice, O barren woman, who does not give birth to [children]; burst out and shout, [you] who do not have birth pains, because many [are] the children of the desolate [woman], even more than [those of] the one who has a husband."