The Rhythm Method, also known as the Calendar Method or the Knaus-Ogino Method (named after Hermann Knaus and Kyusaku Ogino), is a method of natural birth control that involves counting days of a woman's menstrual cycle in order to achieve or avoid pregnancy.
| Rhythm Method | |
|---|---|
 An illustration of the Standard Days Method. This method may be used by women whose menstrual cycles are always between 26 and 32 days in length | |
| Background | |
| Type | natural birth control |
| First use | 1929 |
| Pregnancy rates (first year) | |
| Perfect use | Standard Days: 5% Knaus-Ogino: 9% |
| Typical use | 25% |
| Usage | |
| Reversibility | Yes |
| User reminders | Dependent upon strict user adherence to methodology |
| Clinic review | None |
| Advantages and disadvantages | |
| STI protection | No |
| Weight gain | None |
| Benefits | No side effects, can aid pregnancy achievement |
A recently developed variant of the Rhythm Method is known as the Standard Days Method. Developed by Georgetown University's Institute for Reproductive Health, the Standard Days Method has a simpler rule set and is more effective than Rhythm. A product, called CycleBeads, was developed alongside the method to help the user keep track of estimated high and low fertility points during her menstrual cycle.
Comparison to Fertility Awareness methods
The term 'the rhythm method' is frequently used, in error, to describe any method of tracking fertility. However, there are significant differences between the older Rhythm method, and newer methods of tracking fertility. The Rhythm method relies on statistical estimates and calendar reference, providing an educated guess of the likelihood of fertility. Unlike Rhythm, modern techniques of fertility awareness involve direct observation and charting of several physiological signs of fertility, providing immediate feedback with bodily cues. The Rhythm method is less accurate than modern fertility awareness methods. Because of this, many fertility awareness teachers consider calendar rhythm to have been obsolete for at least 20 years.
At one time, the Rhythm Method was promoted as an acceptable form of natural family planning by the Catholic Church, although, as in the fertility awareness community, more modern methods are being advocated by the leaders of this church, today.
Description and effectiveness
Most menstrual cycles have several days at the beginning that are infertile (pre-ovulatory infertility), a period of fertility, and then several days just before the next menstruation that are infertile (post-ovulatory infertility). The first day of red bleeding is considered day one of the menstrual cycle. The formula for Calendar Rhythm requires the woman to know the length of her menstrual cycles.
Knaus-Ogino Method
To find the estimated length of the pre-ovulatory infertile phase, nineteen (19) is subtracted from the length of the woman's shortest cycle. To find the estimated start of the post-ovulatory infertile phase, ten (10) is subtracted from the length of the woman's longest cycle.[1]
A woman whose menstrual cycles ranged in length from 30 to 36 days would be estimated to be infertile for the first 11 days of her cycle (30-19=11), to be fertile on days 12-25, and to resume infertility on day 26 (36-10=26). When used to avoid pregnancy, the Rhythm Method has a perfect-use failure rate of up to 9% per year.[2]
Standard Days Method
The Standard Days Method may only be used by women whose cycles are always between 26 and 32 days in length. In this system, days 1-7 of a woman's menstrual cycle are considered infertile. Days 8-19 are considered fertile. Infertility is considered to resume beginning on day 20. When used to avoid pregnancy, the Standard Days Method has a perfect-use failure rate of 5% per year.[3]
Imperfect use
Imperfect use of the Rhythm Method would consist of not correctly tracking the length of the woman's cycles, thus using the wrong numbers in the formula, or of having intercourse on an identified fertile day. Imperfect use is fairly common, and the actual failure rate of the Rhythm Method is 25% per year.[2]
Reasons for high failure rate
The Rhythm Method formula makes several assumptions that are not always true.
The postovulatory (luteal) phase has a normal length of 12 to 16 days,[4] and the Rhythm Method formula assumes all women have luteal phase lengths within this range. However, many women have shorter luteal phases, and a few have longer luteal phases.[5] For these women, the Rhythm Method formula incorrectly identifies a few fertile days as being in the infertile period.
The Rhythm Method uses records of past menstrual cycles to predict the length of future cycles. However, the length of the pre-ovulatory phase can vary significantly, depending on the woman's typical cycle length, stress factors, medication, illness, menopause, breastfeeding, and whether she is just coming off hormonal contraception. If a woman with previously regular cycles has a delayed ovulation due to one of these factors, she will still be fertile when the Rhythm Method tells her she is in the post-ovulatory infertile phase. If she has an unusually early ovulation, the Rhythm Method will indicate she is still in the pre-ovulatory infertile phase when she has actually become fertile.
Finally, the Rhythm Method assumes that all bleeding is true menstruation. However, mid-cycle or annovulatory bleeding can be caused by a number of factors. Incorrectly identifying bleeding as menstruation will cause the Rhythm Method's calculations to be incorrect.
History
It is not known exactly when it was first discovered that women have predictable periods of fertility and infertility. St. Augustine wrote in the year 388, "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...?"[6] One book states that "[The Rhythm Method] had been recommended... by a few secular thinkers since the mid-nineteenth century".[7]
However, it was not until 1905 that Theodoor Hendrik Van de Velde, a Dutch gynecologist, showed that women only ovulate once per menstrual cycle.[8] In 1924, Kyusaku Ogino, a Japan gynecologist, developed a formula for use in aiding infertile women time intercourse to achieve pregnancy. The formula was modified to make it suitable for avoiding pregnancy by Hermann Knaus in Austria in 1928, and this was the official Rhythm Method promoted over the next several decades.
While the early Church father Augustine condemned the Rhythm precursor he was aware of ("From this it follows that you consider marriage is not to procreate children, but to satiate lust."),[6] the 1930 encyclical Casti Connubii by Pope Pius XI was controversially interpreted to allow moral use of the (then recently developed) Rhythm Method. 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. However, it was not until Pope Pius XII's 1951 addresses (English translation entitled Moral Questions Affecting Married Life) that the Catholic Church explicitly accepted use of the Rhythm Method.[7]
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 fertility awareness methods over the Rhythm Method.
References
- ^ Kippley, John and Sheila Kippley. The Art of Natural Family Planning. The Couple to Couple League, Cincinnati, OH: 1996. p.154. ISBN 0-926412-13-2
- ^ a b Hatcher, RA (2000). Contraceptive Technology (18th Edition ed.). New York: Ardent Media. ISBN 0-9664902-6-6.
{{cite book}}:|edition=has extra text (help); Unknown parameter|coauthors=ignored (|author=suggested) (help) - ^ Arévalo M, Jennings V, Sinai I (2002). "Efficacy of a new method of family planning: the Standard Days Method" (PDF). Contraception. 65 (5): 333–8. PMID 12057784.
{{cite journal}}: CS1 maint: multiple names: authors list (link) - ^ Weschler, Toni. Taking Charge of Your Fertility. HarperCollins, New York: 2002. p.48 ISBN 0-06-039406-4
- ^ Kippley, p.111
- ^ a b Saint, Bishop of Hippo Augustine (1887). A Select Library of the Nicene and Post-Nicene Fathers of the Christian Church, Volume IV. Grand Rapids, MI: WM. B. Eerdmans Publishing Co. pp. On the Morals of the Manichæans, Chapter 18.
{{cite book}}: Unknown parameter|coauthors=ignored (|author=suggested) (help) - ^ a b Shannon, Marilyn (2001). A History of the Wife (First edition ed.). New York: HarperCollins. ISBN 0-06-019338-7.
{{cite book}}:|edition=has extra text (help) p. 307. - ^ "A Brief History of Fertility Charting". FertilityFriend.com. Retrieved 2006-06-18.
External links
CycleBeads - A website promoting the Standard Days Method