Rhythm method

There's a name for people who use the rhythm method - parents. The rhythm method is a method of birth control involving abstaining from unprotected sex except on days when a woman is believed to be "infertile" determined only by calendar-based calculations. Natural family planning is a newer, more scientifically refined entry into abstinence methods of birth control. NFP does not rely merely on following the calendar. Women using NFP are taught to monitor some or all of: changes in their cervical mucus, a fall in their basal body temperature, as well as the dilation and closure of their cervix to determine approaching fertility and its passing.

Proponents
It is used by:
 * 1) People without easy access to other forms of birth control;
 * 2) People who choose not to use other forms of birth control, often because of religious beliefs or belief in natural remedies and methods in general;
 * 3) People who want to have kids.

Natural Family Planning is assessed by Planned Parenthood's Alan Guttmacher Institute to have a perfect use effectiveness rate of 91%, and an actual user rate of 75%. The method can work well for couples in a stable relationship who are smart enough to learn the various indicia of fertility. Effectiveness increases if barrier methods are employed on each end of the "heading-toward-or-away-from-fertility" days, and intercourse is avoided during the 3-4 days of peak fertility. Catholics, and some fundamentalists, of course, are not allowed to combine NFP with "artificial" contraception.