Methods
There are three main types of NFP: the symptoms-based methods, the calendar-based methods, and the breastfeeding or lactational amenorrhea method. Symptoms-based methods rely on biological signs of fertility, while calendar-based methods estimate the likelihood of fertility based on the length of past menstrual cycles.
Clinical studies by the Guttmacher Institute found that periodic abstinence resulted in a 25.3 percent failure under typical conditions, though it did not differentiate between symptom-based and calendar-based methods.
Read more about this topic: Natural Family Planning
Famous quotes containing the word methods:
“The reading public is intellectually adolescent at best, and it is obvious that what is called “significant literature” will only be sold to this public by exactly the same methods as are used to sell it toothpaste, cathartics and automobiles.”
—Raymond Chandler (1888–1959)
“Cold and hunger seem more friendly to my nature than those methods which men have adopted and advise to ward them off.”
—Henry David Thoreau (1817–1862)
“All good conversation, manners, and action, come from a spontaneity which forgets usages, and makes the moment great. Nature hates calculators; her methods are saltatory and impulsive.”
—Ralph Waldo Emerson (1803–1882)