Is it valid for a woman to marry the man with whom she conceived and gave birth, if the marriage contract is concluded before the expiration of forty days from postpartum bleeding (nifas)?

A woman must repent from adultery and conceal herself with Allah's concealment. It is not permissible for an adulterer to marry an adulteress unless both have repented. If they repented before the marriage contract, then their marriage is valid. Otherwise, it is not valid, and they must renew the contract after repentance. The contract upon her after the cessation of blood and before the passage of forty days does not affect the validity of the contract, because the waiting period (iddah) is by delivery.