What is the ruling regarding the cycle for a pregnant woman when the term 'cycle' is interpreted as the period of purity (at-tuhur)?

Primary text

For a pregnant woman, the ruling is the same as for a minor girl in one view, because the entire period of gestation is considered a single cycle, provided the 'cycle' is understood as the period of purity. If the husband states 'You are divorced in every cycle,' and the wife divorces (i.e., the first pronouncement takes effect) during her pregnancy, she becomes definitively separated (bā'in) upon delivery, because her waiting period concludes with childbirth, preventing another divorce from taking effect. If he renews the marriage contract or takes her back before delivery, and then she becomes pure after the post-natal bleeding (nifas), the second divorce takes effect. Subsequently, when she menstruates and purifies, the third divorce occurs.