Isaac prayed to the Lord for his wife, because she was barren; and the Lord granted his prayer, and his wife Rebekah conceived.22The children struggled together within her; and she said, 'If it is to be this way, why do I live?'* So she went to inquire of the Lord.23And the Lord said to her,
'Two nations are in your womb, and two peoples born of you shall be divided; one shall be stronger than the other, the elder shall serve the younger.'
When her time to give birth was at hand, there were twins in her womb.25The first came out red, all his body like a hairy mantle; so they named him Esau.26Afterwards his brother came out, with his hand gripping Esau’s heel; so he was named Jacob (Genesis 25:21-26)
Check out the video below. It show twins kicking each other in the womb.