Numbers 5:27-28 NIV

27 If she has made herself impure and been unfaithful to her husband, this will be the result: When she is made to drink the water that brings a curse and causes bitter suffering, it will enter her, her abdomen will swell and her womb will miscarry, and she will become a curse.

References for Numbers 5:27

28 If, however, the woman has not made herself impure, but is clean, she will be cleared of guilt and will be able to have children.