| Natural family planning | |
|---|---|
| Background | |
| Type | Behavioral | 
| First use | Ancient: calendar, LAM mid-1930s: BBT 1950s: mucus  | 
| Failure rates (First six months: LAM  Per year: symptoms- and calendar-based)  | |
| Perfect use | LAM: 0.5% Symptoms based: 1–3% Calendar based: 5–9%  | 
| Typical use | LAM: 2% Symptoms based: 2–25% Calendar based: 25%  | 
| Usage | |
| Reversibility | Yes | 
| User reminders | Dependent upon strict user adherence to method | 
| Advantages and disadvantages | |
| STI protection | No | 
| Period advantages | Prediction | 
| Benefits | Personal self-awareness, no side effects, can aid pregnancy achievement, in accord with Catholic teachings, no blocks that affect intercourse | 
 Periodic abstinence is now 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 user was trained properly, and how carefully they followed the protocol. Pregnancy can result in anywhere from 1 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 practiced. If perfectly practised, pregnancy rates can be as low as 1% per year; if imperfectly practised, as high as 25%. (See sidebar.) The largest natural family planning study was of 19,843 women in Calcutta, India who were 52% Hindu, 27% Muslim and 21% Christian. The unexpected pregnancy rate was 0.2 pregnancies/100 women users yearly.
Natural family planning has shown very weak and contradictory results in pre-selecting the gender of a child, with the exception of a Nigerian study at odds with all other findings. Because of these remarkable results, an independent study needs to be repeated in other populations.
Effectiveness can vary widely, depending on the method used, whether the user was trained properly, and how carefully they followed the protocol. Pregnancy can result in anywhere from 1 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 practiced. If perfectly practised, pregnancy rates can be as low as 1% per year; if imperfectly practised, as high as 25%. (See sidebar.) The largest natural family planning study was of 19,843 women in Calcutta, India who were 52% Hindu, 27% Muslim and 21% Christian. The unexpected pregnancy rate was 0.2 pregnancies/100 women users yearly.
Natural family planning has shown very weak and contradictory results in pre-selecting the gender of a child, with the exception of a Nigerian study at odds with all other findings. Because of these remarkable results, an independent study needs to be repeated in other populations.
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 (Christ) put us to shame with the word of 
Ezekiel: 'Put away your fornications' [Eze. 43:9]. 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, St. Augustine
 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
 (the group the early church father St. Augustine wrote of and 
considered to be heretics) believed that it was immoral to create any 
children, thus (by their belief system), 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, St. 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."
Saint Thomas Aquinas wrote in his 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."
In the Catholic Church, the Council of Trent, issued the 
following anathema: "If any one saith that the Church errs in that she 
declares that, for many causes, a separation may take place between 
husband and wife, in regard of bed, or in regard of cohabitation, for a 
determinate or for an indeterminate period; let him be anathema."
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 1880, the Sacred Penitentiary reaffirmed the 1853 ruling, and 
went slightly further. It suggested that, in cases where the couple was 
already practicing 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, Kyusaku Ogino,
 a Japanese gynecologist, and Hermann Knaus, from Austria, working 
independently, each 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 (founded by John Rock) 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.
Later 20th century to present
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. Dr. 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
 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" (50). 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. While a majority of the
 Commission (64 of 68 who voted) recommended allowing other means of 
contraception, Paul VI would determine 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 (one that used 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(1977), and the Creighton Model as part of the Pope Paul VI Institute (1985), both mucus based systems of NFP. 
Today, use of the term natural family planning to describe calendar-based methods is considered 
incorrect by the United States Conference of Catholic Bishops: it considers such methods "inaccurate".  Still, some organizations consider 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 (SDM), 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% American 
women were using "periodic abstinence" (defined as "calendar rhythm" and
 "natural family planning") compared to 60.6% American women 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.
  (Five years after writing the book, the Torodes retracted their 
advocacy of pure NFP and also supported barrier methods as moral; the 
couple divorced in 2011 and both left from conservative Evangelicalism 
to join liberal churches.) Many NFP clinics and teaching organizations are associated with the Catholic Church, as well as The Church of Jesus Christ of Latter-day Saints (LDS Church) and some members of the Muslim faith.
Some fundamental Christians espouse Quiverfull theology, eschewing all forms of birth control, including natural family planning.
Contraception
Some proponents of NFP differentiate it from other forms of birth control by labeling them artificial birth control.  Other NFP literature holds that natural family planning is distinct from contraception.
 Proponents justify this classification system by saying that NFP has 
unique characteristics not shared by any other method of birth 
regulation except for abstinence.  Commonly cited traits are that NFP is
 "open to life," and that NFP alters neither the fertility of the woman nor the fecundity of a particular sex act. That NFP can be used to both avoid or achieve pregnancy may also be cited as a distinguishing characteristic.
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.
Symptoms-based
Some methods of NFP track biological signs of fertility.  When used 
outside of the Catholic concept of NFP, these methods are often referred
 to simply as fertility awareness-based methods rather than NFP. The three primary signs of a woman's fertility are her basal body temperature (BBT), her cervical mucus, and her cervical position. Computerized fertility monitors, such as Lady-Comp,
 may track basal body temperatures, hormonal levels in urine, changes in
 electrical resistance of a woman's saliva, or a mixture of these 
symptoms.
From these symptoms, a woman can learn to assess her fertility 
without use of a computerized device. Some systems use only cervical 
mucus to determine fertility. Two well-known mucus-only methods are the Billings ovulation method and the Creighton Model FertilityCare System.
 If two or more signs are tracked, the method is referred to as a 
symptothermal method. Two popular symptothermal systems are taught by 
the Couple to Couple League and the Fertility Awareness Method (FAM) with Toni Weschler.  A study completed in Germany in 2007 found that tymptothermal method has a method effectiveness of 99.6%.
A study by the World Health Organization involving 869 fertile 
women from Australia, India, Ireland, the Philippines, and El Salvador 
found that 93% could accurately interpret their body's signals 
regardless of education and culture.  In a 36-month study of 5,752 women, the method was 99.86% effective.
A symptohormonal method of NFP developed at Marquette University 
uses the ClearBlue Easy fertility monitor and cycle history to determine
 the fertile window.
 The monitor measures estrogen and LH to determine the peak day. This 
method is also applicable during postpartum, breastfeeding, and 
perimenopause, and requires less abstinence than other NFP methods. Some couples prefer this method because the monitor reading is objective and is not affected by sleep quality as BBT can be.
Calendar-based
Calendar-based methods determine fertility based on a record of the 
length of previous menstrual cycles.  They include the Rhythm Method and
 the Standard Days Method. The Standard Days method was developed and 
proven by the researchers at the Institute for Reproductive Health of 
Georgetown University. CycleBeads, unaffiliated with religious 
teachings, is a visual tool based on the Standard Days method. According
 to the Institute of Reproductive Health, when used as birth control, CB
 has a 95% effectiveness rating. Computer programs are available to help
 track fertility on a calendar.
Lactational amenorrhea
The lactational amenorrhea method (LAM) is a method of avoiding pregnancy based on the natural postpartum infertility that occurs when a woman is amenorrheic and fully breastfeeding.  The rules of the method help a woman identify and possibly lengthen her infertile period.
Debates
Roderick Hindery reported that a number of Western Catholics have 
voiced significant disagreement with the Church's stance on 
contraception. In 1968, the Canadian Conference of Catholic Bishops issued what many interpreted as a dissenting document, the Winnipeg Statement,
 in which the bishops recognized that a number of Canadian Catholics 
found it "either extremely difficult or even impossible to make their 
own all elements of this doctrine" (that of Humanae vitae). Additionally, in 1969, they reasserted the Catholic principle of primacy of conscience,
 a principle that they said should be properly interpreted. They 
insisted that "a Catholic Christian is not free to form his conscience 
without consideration of the teaching of the magisterium, in the particular instance exercised by the Holy Father in an encyclical letter."  Catholics for a Free Choice
 claimed in 1998 that 96% of U.S. Catholic women had used contraceptives
 at some point in their lives and that 72% of U.S. Catholics believed 
that one could be a good Catholic without obeying the Church's teaching 
on birth control. According to a nationwide poll of 2,242 U.S. adults surveyed online in September 2005 by Harris Interactive (they stated that the magnitude of errors cannot be estimated due to sampling errors, non-response, etc.), 90% of U.S. Catholics supported the use of birth control/contraceptives. A survey conducted in 2015 by the Pew Research Center
 among 5,122 U.S. adults (including 1,016 self-identified Catholics) 
stated 76% of U.S. Catholics thought that the Church should allow 
Catholics to use birth control.
In 2003, the BBC's Panorama
 claimed that Church officials have taught that HIV can pass through the
 membrane of the latex rubber from which condoms were made. It was 
considered not true according to the World Health Organization, despite a 2000 report by the National Institutes of Health
 (NIH) stating that consistent use of latex condoms reduced the risk of 
HIV transmission by approximately 85% relative to risk when unprotected, not 100% safe.
In an interview on Dutch television in 2004, Belgian Cardinal Godfried Danneels argued that the use of condoms should be supported to prevent AIDS
 if sex with a person infected with HIV should take place, though it is 
to be avoided. According to Danneels, "the person must use a condom in 
order not to disobey the commandment condemning murder, in addition to 
breaking the commandment which forbids adultery. ... Protecting oneself 
against sickness or death is an act of prevention. Morally, it cannot be
 judged on the same level as when a condom is used to reduce the number 
of births." In 2009, Pope Benedict XVI
 asserted that handing out condoms is not the solution to combating AIDS
 and actually makes the problem worse. He proposed "spiritual and human 
awakening" and "friendship for those who suffer" as solutions.
Artificial family planning proponent Stephen D. Mumford
 claimed that the primary motivation behind the Church's continued 
opposition to contraceptive use is the impossibility to make changes 
without spoiling papal authority with regards to papal infallibility.
 Mumford gives as an example the citation made by dissident theologian 
August Bernhard Hasler of a minority report co-authored by Pope John Paul II prior to his papacy:
If it should be declared that contraception is not evil in itself, then we should have to concede frankly that the Holy Spirit had been on the side of the Protestant churches in 1930 (when the encyclical Casti connubii was promulgated), in 1951 (Pius XII's address to the midwives), and in 1958 (the address delivered before the Society of Hematologists in the year the pope died). It should likewise have to be admitted that for a half century the Spirit failed to protect Pius XI, Pius XII, and a large part of the Catholic hierarchy from a very serious error. This would mean that the leaders of the Church, acting with extreme imprudence, had condemned thousands of innocent human acts, forbidding, under pain of eternal damnation, a practice which would now be sanctioned. The fact can neither be denied nor ignored that these same acts would now be declared licit on the grounds of principles cited by the Protestants, which popes and bishops have either condemned or at least not approved.
It is said that none of the instances cited falls under the domain of
 papal infallibility; the Pope is not considered infallible except in 
the rare, solemn occasions when he is speaking ex cathedra. According to M. R. Gagnebet, though the encyclical Humanae vitae
 is considered by some to be a non-infallible document, "the doctrinal 
authority of the Pope and the Bishops is not limited to infallible 
teaching. The duty of obedience is not restricted to definitions of 
faith".
Theological opposition has come from some denominations of Protestant Christianity. The Reformed theologian John Piper's Desiring God ministry states of NFP, "There is no reason to conclude that natural family planning is appropriate but that 'artificial' (non-abortive) means are not." Eastern Orthodox
 couple Sam and Bethany Torode, former advocates of NFP-only, have 
redacted their position to include barrier methods and explain their 
current theology this way:
We also see honest congruity with the language of the body by saying "no" to conception with our bodies (via barrier methods or sensual massage) when our minds and hearts are also saying "no" to conception. We don’t believe this angers God, nor that it leads to the slippery slope of relativism or divorce. We strongly disagree with the idea that this is a mortal sin.... It’s a theological attack on women to always require that abstinence during the time of the wife’s peak sexual desire (ovulation) for the entire duration of her fertile life, except for the handful of times when she conceives.
Traditionalist Catholic priest Francis Ripley criticizes the concept: 
The use of the term "Natural Family Planning" has come under sharp attack from traditional Catholic writers in recent years because it implies the right of the couple to "plan" their family; whereas the Catholic norm is to let God plan one's family and to accept the children when (and if) God gives them--as a blessing from Him on the marital union and on society.