Are children predestined, or does supplication change what God has bestowed upon us? And was the miscarriage that occurred after two attempts at gender selection predestined, or is it related to gender selection or the destruction of embryos?

Allah decreed the destinies of creation fifty thousand years before He created the heavens and the earth. Thus, what Allah has decreed will inevitably come to pass. Destiny is of two types: Al-Mubram (the unchangeable) which does not alter, and Al-Mu'allaq (the suspended) which can change through supplication (du'a), charity (sadaqah), and righteousness (birr). Supplication is one of the most powerful means of averting destiny, just as other means, such as food and drink, are necessary for their decreed outcomes to be realized. One must not lament what has passed, for everything that befalls a person is decreed and written, and saying "if only" opens the door to Satan's work. There is no impediment to destroying fertilized eggs outside the womb.