Natural Family Planning (NFP) is the name for a collection of methods which use the natural, biological signs of a woman’s menstrual cycle to predict fertility. With that knowledge, husbands and wives can adjust their intimacy to increase their chances of conceiving a child or – for serious reasons – to postpone or avoid pregnancy (See Human Vitae 16)
Unlike artificial contraceptives, Natural Family Planning does not actively change the sexual act to render it unfruitful; instead, it identifies times when intimacy should be avoided if there is a reason to avoid pregnancy.
Thus NFP respects the two inseparable aspects of sexuality – the closer union of husband and wife, and openness to children, the fruit of sexuality. Moreover, NFP does this without introducing artificial hormones or devices into a woman’s body, while also promoting communication, intimacy, and trust within a marriage.