What is the ruling on "istilhaq" in Islamic Sharia, which is when a woman gives birth years after her husband's death or divorce, and the child is attributed to him, on the grounds that the fetus remained in the womb?

The determination of the 'iddah (waiting period) as four months and ten days, or three menstrual cycles, is for a woman who is not pregnant. However, if a woman suspects she is pregnant, she waits until her doubt is removed by giving birth, based on the Almighty's saying: ﴿And for those who are pregnant, their term is until they deliver their burdens.﴾ [Al-Talaq: 4]. This ruling is practiced in the madhabs (schools of thought) of Ahl al-Sunnah, and it is not a Mauritanian superstition. Rather, it is a legitimate religious matter in which the pregnancy is attributed to her deceased or divorced former husband, because his lineage is known.