Natural family planning
Natural family planning comprises the family planning methods approved by the Catholic Church and some Protestant denominations for both achieving and postponing or avoiding pregnancy. In accordance with the church's teachings regarding sexual behavior, NFP excludes the use of other methods of birth control, which it refers to as "artificial contraception".
Periodic abstinence, the crux of NFP, is deemed moral by the Church for avoiding or postponing pregnancy for just reasons. When used to avoid pregnancy, couples may engage in sexual intercourse during a woman's naturally occurring infertile times such as during portions of her ovulatory cycle. Various methods may be used to identify whether a woman is likely to be fertile; this information may be used in attempts to either avoid or achieve pregnancy.
Effectiveness can vary widely, depending on the method used, whether the users were trained properly, and how carefully the couple followed the protocol. Pregnancy can result in up to 25% of the user population per year for users of the symptoms-based or calendar-based methods, depending on the method used and how carefully it was practised.
Natural family planning has shown very weak and contradictory results in pre-selecting the sex of a child.
History
Pre-20th century
In ancient history, some Christian writers were against abstinence to prevent childbirth and some allowed it. Possibly the earliest Christian writing about periodic abstinence was by Clement of Alexandria. He wrote, "Let the Educator put us to shame with the word of Ezekiel: 'Put away your fornications' . Why, even unreasoning beasts know enough not to mate at certain times. To indulge in intercourse without intending children is to outrage nature, whom we should take as our instructor."In the year 388, Augustine of Hippo wrote against the Manichaeans: "Is it not you who used to counsel us to observe as much as possible the time when a woman, after her purification, is most likely to conceive, and to abstain from cohabitation at that time...?" The Manichaeans believed that it was immoral to create any children, thus, trapping souls in mortal bodies. Augustine condemned them for their use of periodic abstinence during fertile periods: "From this it follows that you consider marriage is not to procreate children, but to satiate lust." About the year 401, Augustine wrote "Of the Good of Marriage" in which he affirmed married couples have the option of having sex without either of them intending procreation: "For, whereas that natural use, when it pass beyond the compact of marriage, that is, beyond the necessity of begetting, is pardonable in the case of a wife, damnable in the case of an harlot; that which is against nature is execrable when done in the case of an harlot, but more execrable in the case of a wife."
Thomas Aquinas wrote in Summa Contra Gentiles: "Hence it is clear that every emission of the semen is contrary to the good of man, which takes place in a way whereby generation is impossible; and if this is done on purpose, it must be a sin. I mean a way in which generation is impossible in itself as is the case in every emission of the semen without the natural union of male and female: wherefore such sins are called 'sins against nature.' But if it is by accident that generation cannot follow from the emission of the semen, the act is not against nature on that account, nor is it sinful; the case of the woman being barren would be a case in point."
Protestant Reformers such as Martin Luther and John Calvin were opposed to unnatural birth control. Centuries later, John Wesley, the leader of the Methodist movement said that unnatural birth control could destroy one's soul.
If the Manichaeans had an accurate idea of the fertile portion of the menstrual cycle, such knowledge died with them. Documented attempts to prevent pregnancy by practicing periodic abstinence do not appear again until the mid-19th century, when various calendar-based methods were developed "by a few secular thinkers". The Roman Catholic Church's first recorded official approval of periodic abstinence from 1853, where a ruling of the church's Sacred Penitentiary addressed the topic. Distributed to confessors, the ruling stated that couples who had, on their own, begun the practice of periodic abstinence—if they had "grave reasons"—were not sinning by doing so.
In the Catholic Church, a grave/significant reason for using NFP can include social, economical, medical and other analogous reasons that may motivate a couple to practise it to postpone pregnancy. The church holds that the motivations behind NFP should not be selfish or self-centered.
In 1880, the Sacred Penitentiary reaffirmed the 1853 ruling and went slightly further. It suggested that, in cases where the couple was already practising artificial birth control and could not be dissuaded to cease attempting birth regulation, the confessor might morally teach them of periodic abstinence.
Early 20th century
In 1905, Theodoor Hendrik van de Velde, a Dutch gynecologist, showed that women only ovulate once per menstrual cycle. In the 1920s Japanese gynecologist Kyusaku Ogino and Austrian Hermann Knaus independently made the discovery 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 Knaus and Ogino's discoveries to create the rhythm method. Smulders published his work with the Dutch Roman Catholic medical association, and this was the official rhythm method promoted over the next several decades. While maintaining procreation as the primary function of intercourse, the December 1930 encyclical Casti connubii by Pope Pius XI gave recognition to a secondary—unitive—purpose of sexual intercourse. This encyclical stated that there was no moral stain associated with having marital intercourse at times when "new life cannot be brought forth". This referred primarily to conditions such as current pregnancy and menopause. In 1932, a Catholic physician published a book titled The Rhythm of Sterility and Fertility in Women describing the method, and the 1930s also saw the first U.S. Rhythm Clinic to teach the method to Catholic couples. It was during this decade that Rev. Wilhelm Hillebrand, a Catholic priest in Germany, developed a system for avoiding pregnancy based on basal body temperature.
20th century to present day
A minority of Catholic theologians continued to doubt the morality of periodic abstinence. Some historians consider two speeches delivered by Pope Pius XII in 1951 to be the first unequivocal acceptance of periodic abstinence by the Catholic Church. The 1950s also saw another major advance in fertility awareness knowledge: Dr. John Billings discovered the relationship between cervical mucus and fertility while working for the Melbourne Catholic Family Welfare Bureau. Billings and several other physicians 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.The Vatican II Constitution on the Church in the Modern World document declared: "While not making the other purposes of matrimony of less account, the true practice of conjugal love, and the whole meaning of the family life which results from it, have this aim: that the couple be ready with stout hearts to cooperate with the love of the Creator and the Savior. Who through them will enlarge and enrich His own family day by day". Beyond that the council of bishops was told to leave to the Pontifical Commission on Birth Control the task of advising Pope Paul VI on the issue. 64 of the 68 Commission members who voted recommended allowing other means of contraception, but Paul VI determined otherwise.
Humanae Vitae, published in 1968 by Pope Paul VI, addressed a pastoral directive to scientists: "It is supremely desirable that medical science should by the study of natural rhythms succeed in determining a sufficiently secure basis for the chaste limitation of offspring." This is interpreted as favoring the then-new, more reliable symptoms-based fertility awareness methods over the rhythm method. Just a few years later, in 1971, the first organization to teach a symptothermal method, using both mucus and temperature observations, was started. Now called Couple to Couple League International, this organization was founded by John and Sheila Kippley, lay Catholics, along with Dr. Konald Prem. During the following decade, other now-large Catholic organizations were formed: Family of the Americas, and the Creighton Model as part of the Pope Paul VI Institute, both mucus-based systems of NFP.
Use of the term natural family planning to describe calendar-based methods is considered incorrect by the United States Conference of Catholic Bishops, which considers such methods "inaccurate". Some organizations have considered calendar-based methods to be forms of NFP. For example, in 1999 the Institute for Reproductive Health at Georgetown University developed the Standard Days Method, which is more effective than the rhythm method. SDM is promoted by Georgetown University as a form of natural family planning.
Prevalence
It is estimated that 2–3% of the world's reproductive age population relies on periodic abstinence to avoid pregnancy. However, what portion of this population should be considered NFP users is unclear. Some Catholic sources consider couples that violate the religious restrictions associated with natural family planning to not be NFP users.There is little data on the worldwide use of natural family planning. In Brazil, NFP is the third most popular family planning method. The "safe period" method of fertility awareness is the most common family planning method used in India, although condoms are used by some. Of all American women surveyed nationally in 2002, only 0.9% were using "periodic abstinence" compared to 60.6% using other contraceptive methods. In Italy, where the vast majority of citizens claims to be Catholic, NFP methods are rarely taught.
In 2002, Sam and Bethany Torode, then a Protestant Christian couple, published a book advocating NFP use. Many NFP clinics and teaching organizations are associated with the Catholic Church, as well as the Church of Jesus Christ of Latter-day Saints and some members of the Muslim faith.
Some fundamental Christians espouse Quiverfull theology, eschewing all forms of birth control, including natural family planning.