The World Federation One Stop Fiqh

Ruling 2466

If after the conclusion of a marriage contract a woman becomes apostate, whether that be millī or fiṭrī, her marriage contract becomes void. In the event that her husband has not had sexual intercourse with her, she does not have to observe ʿiddah. The same applies if she becomes apostate after sexual intercourse but she is postmenopausal (yāʾisah) [as defined below] or a minor (ṣaghīrah). However, if she is of the age of women who experience menstruation (ḥayḍ), she must observe ʿiddah  according to the instructions that will be mentioned in the laws on divorce. If she reverts to Islam within the ʿiddah period, the marriage contract will remain as it is, although it is better that if the couple wish to live together they should contract a marriage again, and if they wish to separate they should get a divorce. A postmenopausal woman in this ruling is a woman who has reached the age of fifty, and due to her advanced age, she does not experience ḥayḍ and has no expectation of experiencing it again.