Is ghusl required immediately after intercourse, or after menstruation ends if menstrual bleeding occurs right after intercourse?

If a husband has intercourse with his wife and she then menstruates before performing ghusl (ritual bath) from major impurity, she is not required to perform ghusl until she becomes pure. However, if she wishes to recite the Quran, she must perform ghusl from major impurity, because, according to the preponderant opinion, it is not permissible for someone in a state of major impurity (junub) to recite the Quran.