Does a divorce issued by a husband who was unaware of his wife's menstruation count, and is she obligated to observe the waiting period ('iddah)?

The majority of scholars hold that a divorce pronounced during menstruation is valid, despite being an innovation (bid'ah). This is the ruling we adopt. There is no harm for a layperson to act upon the opinion of some scholars in matters where there is a difference of opinion, as long as he is confident in the correctness of that opinion and is not merely following his desires. If this divorce does not complete the three divorces, it is a revocable divorce (ṭalāq rajʿī), meaning the husband has the right to take his wife back during her waiting period (ʿiddah) without her consent. However, if this divorce completes the three divorces, it is recommended to present the matter to trustworthy scholars. If a dispute arises, the resolution lies with the Sharia judge.