Is anything other than repentance required of a woman who used birth control methods and then regretted her action, knowing that her husband was aware of it?

Islamic law encourages having children and increasing offspring. Permanent cessation of procreation falls into two categories:

First: Due to necessity, such as when pregnancy poses a danger to the mother's life. In this case, permanent cessation is permissible.

Second: Without necessity. This is a grave offense and a tremendous sin because it is an interference with Allah's creation and a halting of procreation, which the Prophet, peace be upon him, encouraged.

The Islamic Fiqh Academy has prohibited the complete removal of the ability to procreate except for a legitimate necessity.

If the cessation of procreation is due to necessity, then there is no blame upon you. Otherwise, you have committed something forbidden, and you must offer sincere repentance and cease using the method.