Editing Calendar-based contraceptive methods (section)

==History==

===Early methods===
It is not known if historical cultures were aware of what part of the menstrual cycle is most fertile. In the year 388, [[Augustine of Hippo]] wrote of periodic abstinence. Addressing followers of [[Manichaeism]], his former religion, he said, "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...?"<ref name="augustine">{{cite book |last=Saint |first=Bishop of Hippo Augustine |editor=Philip Schaff |title=A Select Library of the Nicene and Post-Nicene Fathers of the Christian Church, Volume IV |publisher=WM. B. Eerdmans Publishing Co. |year=1887 |location=Grand Rapids, MI |chapter-url=http://www.ccel.org/ccel/schaff/npnf104.iv.v.xx.html |chapter=Chapter 18.—Of the Symbol of the Breast, and of the Shameful Mysteries of the Manichæans}}</ref>  If the Manichaieans practiced something like the Jewish [[niddah|observances of menstruation]], then the "time... after her purification" would have indeed been when "a woman... is most likely to conceive."<ref name="green">{{cite book |first=Shirley |last=Green |year=1972 |title=The Curious History of Contraception |publisher=St. Martin's Press |location=New York |isbn=0-85223-016-8 |pages=138–43}}</ref>  Over a century previously, however, the influential [[Ancient Greek medicine|Greek physician]] [[Soranus of Ephesus|Soranus]] had written that "the time directly before and after menstruation" was the most fertile part of a woman's cycle; this inaccuracy was repeated in the 6th century by the [[Byzantine]] physician [[Aëtius Amidenus|Aëtius]]. Similarly, a [[China|Chinese]] sex manual written close to the year 600 stated that only the first five days following menstruation were fertile.<ref name="green"/> Some historians believe that Augustine, too, incorrectly identified the days immediately after menstruation as the time of highest fertility.<ref name="mclaren">{{cite book |last=McLaren |first=Angus |title=A History of Contraception: From Antiquity to the Present Day |publisher=Blackwell Publishers |year=1992 |location=Oxford |page=74 |isbn=0-631-18729-4}}</ref>

Written references to a "safe period" do not appear again for over a thousand years.<ref name="green"/> Scientific advances prompted a number of secular thinkers to advocate periodic abstinence to avoid pregnancy:<ref name="wife"/> in the 1840s it was discovered that many animals ovulate during [[estrus]].  Because some animals (such as [[dog]]s) have a bloody discharge during estrus, it was assumed that menstruation was the corresponding most fertile time for women.  This inaccurate theory was popularized by physicians [[Theodor Ludwig Wilhelm Bischoff|Bischoff]], [[Félix Archimède Pouchet]], and Adam Raciborski.<ref name="green"/><ref name="mclaren"/> In 1854, an [[English people|English]] physician named George Drysdale correctly taught his patients that the days near menstruation are the ''least'' fertile, but this remained the minority view for the remainder of the 19th century.<ref name="green"/>

===Knaus–Ogino or rhythm method===
In 1905 [[Theodoor Hendrik van de Velde]], a Dutch gynecologist, showed that women only ovulate once per menstrual cycle.<ref>{{cite web | title=A Brief History of Fertility Charting | work=FertilityFriend.com | url=http://www.fertilityfriend.com/Faqs/A_brief_history_of_fertility_charting.html | access-date=2006-06-18}}</ref>  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.<ref name="singer">{{cite book |first=Katie |last=Singer |year=2004 |title=The Garden of Fertility |publisher=Avery | location=New York | isbn=1-58333-182-4 |pages=226–7}}</ref> Ogino used his discovery to develop a formula for use in aiding infertile women to time intercourse to achieve pregnancy.<!-- This if from the Japanese article on Ogino (as best I could tell from the internet translator I used), but that page does not cite its sources -->

In 1930, Johannes Smulders, a [[Roman Catholic]] physician from the Netherlands, used Knaus and Ogino's discoveries to create a method for ''avoiding'' pregnancy. Smulders published his work with the Dutch Roman Catholic medical association, and this was the official rhythm method promoted over the next several decades.<ref name="singer" /> In 1932 a Catholic physician, Dr. Leo J Latz, published a book titled ''The Rhythm of Sterility and Fertility in Women'' describing the method,<ref name="wife">{{cite book | first=Marilyn | last=Yalom | year=2001 | title=A History of the Wife | edition=First | publisher=HarperCollins | location=New York | isbn=0-06-019338-7 | pages=[https://archive.org/details/historyofwife00mari/page/297 297]–8, 307 | url-access=registration | url=https://archive.org/details/historyofwife00mari }}</ref> and the 1930s also saw the first U.S. Rhythm Clinic (founded by [[John Rock (American scientist)|John Rock]]) to teach the method to Catholic couples.<ref>{{cite magazine |last=Gladwell |first=Malcolm |title=John Rock's Error | magazine = The New Yorker |date= 2000-03-10 }}</ref>

===Later 20th century to present===
In the first half of the 20th century, most users of the rhythm method were Catholic; they were following their church's teaching that all other methods of birth control were sinful.  In 1968 the encyclical ''[[Humanae vitae]]'' included the statement, "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.  Currently, many fertility awareness teachers consider the rhythm method to have been obsolete for at least 20 years.<ref name="tcoyf" />

New attention was drawn to calendar-based methods in 2002, when the Institute for Reproductive Health at [[Georgetown University]] introduced the Standard Days Method.  Designed to be simpler to teach and use than the older rhythm method, the Standard Days Method was initially integrated piloted in 30 [[family planning]] programs worldwide. However, only 16 countries scaled up beyond pilots, with limited adoption since.<ref>{{cite journal |last1=Weis |first1=Julianne |last2=Festin |first2=Mario |title=Implementation and Scale-Up of the Standard Days Method of Family Planning: A Landscape Analysis |journal=Global Health, Science and Practice |pages=114–124 |doi=10.9745/GHSP-D-19-00287 |date=30 March 2020|volume=8 |issue=1 |pmid=32033980 |pmc=7108942 }}</ref><ref>{{cite journal |last1=Marston |first1=Cicely A. |last2=Church |first2=Kathryn |title=Does the evidence support global promotion of the calendar-based Standard Days Method® of contraception? |url=https://pubmed.ncbi.nlm.nih.gov/26794286/ |journal=Contraception |access-date=15 October 2024 |pages=492–497 |doi=10.1016/j.contraception.2016.01.006 |date=June 2016|volume=93 |issue=6 |pmid=26794286 }}</ref><ref>{{cite journal |last1=Wright |first1=Kelsey |last2=Iqteit |first2=Hiba |last3=Hardee |first3=Karen |title=Standard Days Method of contraception: Evidence on use, implementation, and scale up |url=https://knowledgecommons.popcouncil.org/departments_sbsr-rh/885/ |website=Reproductive Health |access-date=15 October 2024 |doi=10.31899/rh9.1057 |date=1 January 2015}}</ref>