Fertility awareness
Fertility awareness refers to a set of practices used to determine the fertile and infertile phases of a woman's menstrual cycle. Fertility awareness methods may be used to avoid pregnancy, to achieve pregnancy, or as a way to monitor gynecological health.
Methods of identifying infertile days have been known since antiquity, but scientific knowledge gained during the past century has increased the number, variety, and especially accuracy of methods.
Systems of fertility awareness rely on observation of changes in one or more of the primary fertility signs, tracking menstrual cycle length and identifying the fertile window based on this information, or both. Other signs may also be observed: these include breast tenderness and mittelschmerz, urine analysis strips known as ovulation predictor kits, and microscopic examination of saliva or cervical fluid. Also available are computerized fertility monitors.
Terminology
Symptoms-based methods involve tracking one or more of the three primary fertility signs: basal body temperature, cervical mucus, and cervical position. Systems relying exclusively on cervical mucus include the Billings ovulation method, the Creighton model, and the Two-Day Method. Symptothermal methods combine observations of basal body temperature, cervical mucus, and sometimes cervical position. Calendar-based methods rely on tracking a woman's cycle and identifying her fertile window based on the lengths of her cycles. The best known of these methods is the Standard Days Method. The Calendar-Rhythm method is also considered a calendar-based method, though it is not well defined and has many different meanings to different people.Systems of fertility awareness may be referred to as fertility awareness–based methods; the term Fertility Awareness Method refers specifically to the system taught by Toni Weschler. The term natural family planning is sometimes used to refer to any use of fertility awareness methods, the lactational amenorrhea method and periodic abstinence during fertile times. A method of fertility awareness may be used by natural family planning users to identify these fertile times.
Women who are breastfeeding a child and wish to avoid pregnancy may be able to practice the lactational amenorrhea method. The lactational amenorrhea method is distinct from fertility awareness, but because it also does not involve contraceptives, it is often presented alongside fertility awareness as a method of "natural" birth control.
Within the Catholic Church and some Protestant denominations, the term natural family planning is often used to refer to Fertility Awareness pointing out it is the only method of family planning approved by the Church.
History
Development of calendar-based methods
It is not known exactly when it was first discovered that women have predictable periods of fertility and infertility. It is already clearly stated in the Talmud tractate Niddah, that a woman only becomes pregnant in specific periods in the month, which seemingly refers to ovulation. St. Augustine wrote about periodic abstinence to avoid pregnancy in the year 388. One book states that periodic abstinence was recommended "by a few secular thinkers since the mid-nineteenth century," but the dominant force in the twentieth century popularization of fertility awareness-based methods was the Roman Catholic Church.In 1905 Theodoor Hendrik van de Velde, a Dutch gynecologist showed that women only ovulate once per menstrual cycle. In the 1920s, Kyusaku Ogino, a Japanese gynecologist, and Hermann Knaus, from Austria, independently discovered that ovulation occurs about fourteen days before the next menstrual period. Ogino used his discovery to develop a formula for use in aiding infertile women to time intercourse to achieve pregnancy. In 1930, John Smulders, a Roman Catholic physician from the Netherlands, used this discovery to create a method for avoiding pregnancy. Smulders published his work with the Dutch Roman Catholic medical association, and this was the first formalized system for periodic abstinence: the rhythm method.
Introduction of temperature and cervical mucus signs
In the 1930s, Reverend Wilhelm Hillebrand, a Catholic priest in Germany, developed a system for avoiding pregnancy based on basal body temperature. This temperature method was found to be more effective at helping women avoid pregnancy than were calendar-based methods. Over the next few decades, both systems became widely used among Catholic women. Two speeches delivered by Pope Pius XII in 1951 gave the highest form of recognition to the Catholic Church's approval—for couples who needed to avoid pregnancy—of these systems. In the early 1950s, John Billings discovered the relationship between cervical mucus and fertility while working for the Melbourne Catholic Family Welfare Bureau. Billings and several other physicians, including his wife, Dr. Evelyn Billings, studied this sign for a number of years, and by the late 1960s had performed clinical trials and begun to set up teaching centers around the world.First symptoms-based teaching organizations
While Dr. Billings initially taught both the temperature and mucus signs, they encountered problems in teaching the temperature sign to largely illiterate populations in developing countries. In the 1970s they modified the method to rely on only mucus. The international organization founded by Dr. Billings is now known as the World Organization Ovulation Method Billings.The first organization to teach a symptothermal method was founded in 1971. John and Sheila Kippley, lay Catholics, joined with Dr. Konald Prem in teaching an observational method that relied on all three signs: temperature, mucus, and cervical position. Their organization is now called Couple to Couple League International. The next decade saw the founding of other now-large Catholic organizations, Family of the Americas, teaching the Billings method, and the Pope Paul VI Institute, teaching a new mucus-only system called the Creighton Model.
Up until the 1980s, information about fertility awareness was only available from Catholic sources. The first secular teaching organization was the Fertility Awareness Center in New York, founded in 1981. Toni Weschler started teaching in 1982 and published the bestselling book Taking Charge of Your Fertility in 1995. Justisse was founded in 1987 in Edmonton, Canada. These secular organizations all teach symptothermal methods. Although the Catholic organizations are significantly larger than the secular fertility awareness movement, independent secular teachers have become increasingly common since the 1990s.