Pain in childbirth came about as part of the curse because of sin (Gen 3:16). Those pains are extreme (Psalms 48:6; Isa 13:8; 21:3; Jer 4:31; 6:24) and inevitable (1 Thes 5:3). Matthew Henry notes that the world’s roses are surrounded by thorns. The use of this thought of painful childbirth in the Old Testament is primarily to note the suddenness and inevitability of the birth when its time had come, but here Jesus uses it to contrast the state of mind of the mother before and after the birth.

Genesis 3:16  To the woman he said, “I will greatly increase your pains in childbearing; with pain you will give birth to children. Your desire will be for your husband, and he will rule over you.”

Psalms 48:6  Trembling seized them there, pain like that of a woman in labour.

Isaiah 13:8  Terror will seize them, pain and anguish will grip them; they will writhe like a woman in labour. They will look aghast at each other, their faces aflame.

Isaiah 21:3  At this my body is racked with pain, pangs seize me, like those of a woman in labour; I am staggered by what I hear, I am bewildered by what I see.

Jeremiah 4:31  I hear a cry as of a woman in labour, a groan as of one bearing her first child—the cry of the Daughter of Zion gasping for breath, stretching out her hands and saying, “Alas! I am fainting; my life is given over to murderers.”

Jeremiah 6:24  We have heard reports about them, and our hands hang limp. Anguish has gripped us, pain like that of a woman in labour.

1 Thessalonians 5:3  While people are saying, “Peace and safety,” destruction will come on them suddenly, as labour pains on a pregnant woman, and they will not escape.

Such passages as (Isa 26:17-19, Hos 13:13-15, Isa 66:7-14) associated a pain like that of childbirth with the emergence of the new Israel and the Messianic Kingdom. The Jews believed that there were 2 ages; the present age, which was all bad, and the age to come, which was the golden age of God, when Messiah would rule. In between lay a time of great pain (Isa 13:9, Joel 2:1-2) and they called that time the birth pangs that would precede the coming of Messiah. The use of this simile by Jesus was not just to tell His disciples that their great pain would be remembered no more after it was turned into joy. He also had a deeper truth to pass on to them.

Isaiah 26:17-19  As a woman with child and about to give birth writhes and cries out in her pain, so were we in your presence, O LORD.  We were with child, we writhed in pain, but we gave birth to wind. We have not brought salvation to the earth; we have not given birth to people of the world.  But your dead will live; their bodies will rise. You who dwell in the dust, wake up and shout for joy. Your dew is like the dew of the morning; the earth will give birth to her dead.

Hosea 13:13-15  Pains as of a woman in childbirth come to him, but he is a child without wisdom; when the time arrives, he does not come to the opening of the womb.  “I will ransom them from the power of the grave; I will redeem them from death. Where, O death, are your plagues? Where, O grave, is your destruction? “I will have no compassion,  even though he thrives among his brothers. An east wind from the LORD will come, blowing in from the desert; his spring will fail and his well dry up. His storehouse will be plundered of all its treasures.

Isaiah 66:7-14  “Before she goes into labour, she gives birth; before the pains come upon her, she delivers a son.  Who has ever heard of such a thing? Who has ever seen such things? Can a country be born in a day or a nation be brought forth in a moment? Yet no sooner is Zion in labour than she gives birth to her children.  Do I bring to the moment of birth and not give delivery?” says the LORD. “Do I close up the womb when I bring to delivery?” says your God.  “Rejoice with Jerusalem and be glad for her, all you who love her; rejoice greatly with her, all you who mourn over her.  For you will nurse and be satisfied at her comforting breasts; you will drink deeply and delight in her overflowing abundance.”  For this is what the LORD says: “I will extend peace to her like a river, and the wealth of nations like a flooding stream; you will nurse and be carried on her arm and dandled on her knees.  As a mother comforts her child, so will I comfort you; and you will be comforted over Jerusalem.”  When you see this, your heart will rejoice and you will flourish like grass; the hand of the LORD will be made known to his servants, but his fury will be shown to his foes.

Isaiah 13:9  See, the day of the LORD is coming—a cruel day, with wrath and fierce anger—to make the land desolate and destroy the sinners within it.

Joel 2:1-2  Blow the trumpet in Zion; sound the alarm on my holy hill. Let all who live in the land tremble, for the day of the LORD is coming. It is close at hand—a day of darkness and gloom, a day of clouds and blackness. Like dawn spreading across the mountains a large and mighty army comes, such as never was of old nor ever will be in ages to come.

Note that this is also an appropriate simile since Jesus is the firstborn from the dead (Col 1:18, Rev 1:5).

Colossians 1:18  And he is the head of the body, the church; he is the beginning and the firstborn from among the dead, so that in everything he might have the supremacy.

Revelation 1:5  and from Jesus Christ, who is the faithful witness, the firstborn from the dead, and the ruler of the kings of the earth. To him who loves us and has freed us from our sins by his blood,