Why do Roman Catholics allow the rhythm method?

Roman Catholics do not allow the rhythm method. The rhythm method is a form of natural family planning that involves avoiding intercourse during the fertile window of a woman's menstrual cycle. The Catholic Church teaches that all forms of contraception are immoral, including natural family planning methods like the rhythm method. The Church believes that contraception interferes with the natural process of procreation and that it is only permissible to have sexual intercourse for the purpose of procreation.