Content deleted Content added
Citation bot (talk | contribs) Removed URL that duplicated identifier. Removed access-date with no URL. | Use this bot. Report bugs. | #UCB_CommandLine |
|||
Line 28:
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?
==Types and effectiveness==
Line 59:
One concern related to the use of calendar-based methods is their relatively high failure rate, compared to other methods of birth control. Even when used perfectly, calendar-based methods, especially the rhythm method, result in a high pregnancy rate among couples intending to avoid pregnancy. Of commonly known methods of birth control, only the [[cervical cap]] and [[contraceptive sponge]] have comparably high failure rates. This lower level of reliability of calendar-based methods is because their formulas make several assumptions that are not always true.<ref name="kippleycalendar">Kippley, p.154</ref>
The postovulatory ([[Menstrual cycle#Luteal phase|luteal]]) phase has a normal length of 12 to 16 days,<ref>Weschler, p.48.</ref> 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.<ref>Kippley, p.111</ref> For these women, the rhythm method formula incorrectly identifies a few fertile days as being in the infertile period.<ref name="kippleycalendar" /> Roughly 30-50% of women have phases outside this range.<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?
Finally, calendar-based methods assume that all bleeding is true menstruation. However, mid-cycle or [[anovulatory bleeding]] can be caused by a number of factors.<ref>Kippley, pp.413-415</ref> Incorrectly identifying bleeding as menstruation will cause the method's calculations to be incorrect.<ref name="kippleycalendar" />
| |||