All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad, sallallaahu ‘alayhi wa sallam, is His Slave and Messenger.
The ‘Iddah (waiting period) of the divorced woman starts from the day the divorce takes place, i.e. when the husband utters it or when the court issues its final ruling regarding it.
Thus, the ‘Iddah does not start when the court issues an initial ruling that can be annulled. One Fatwa of "Fataawa Al-Azhar" reads: "The woman does not start the ‘Iddah of the default divorce issued by the court unless it is final, i.e. the duration of the first and second stage appeals expired and it was not appealed at either stage, or it was appealed but (the first ruling) was confirmed. If the ruling of divorce is not final, then divorce does not take place with its effects like 'Iddah until it becomes final." [Fataawa Al-Azhar 2/97]
For more benefit, please refer to Fatwa 88375.
Allaah Knows best.