Effectiveness and Reliability of the Calendar Rhythm Method
In case if this method of birth control is not used perfectly, or if a woman has unprotected sexual relations during her most fertile days, this can lead to a relative increase in the failure rate of Calendar Rhythm Method. In accordance with the statistics, from 100 women, who use this method of Fertility Awareness, about 25 may become pregnant accidentally. However, even if this method is used correctly and perfectly, there is still about 9% of unplanned pregnancy occurrence.
In addition, there exist a lot of factors, which can make the Rhythm Method not very reliable method of Natural Family Planning. Besides some usual mistakes, which can be made by every woman, such as tracking her menstrual cycles incorrectly, using some wrong formula to find the fertile or infertile phase of the cycle, having unprotected sexual relations during the fertile period, unwillingness of a woman’s partner, there are some certain flaws in this method as well.
The formula, which is used to determine the woman’s fertile days is based only on the assumption that every woman ovulates exactly in the middle of her menstrual cycle. Of no doubt, many women do so, however, others experience ovulation earlier, and there are even women, who do not have ovulation up until their menstruation. In addition, some women may have mid – cycle bleeding, which they may consider as a normal menstrual cycle, and this will result in a wrong calculation of cycle days. In any of these cases it is extremely difficult to predict the time of ovulation correctly, which may cause a woman to unknowingly have an unprotected sexual contact during her fertile phase.
There is another reason for the increased failure rate of the Calendar Rhythm Method – it is that a woman has to use her past cycles in order to predict her future cycles. As a rule past patterns may be sufficient to provide a woman with a guideline for her future cycle, however, any minor change in her lifestyle: taking some medications, illness, breastfeeding, dealing with stress, etc, and there is a risk that the menstrual cycle gets changed. Even if none of these factors would be taken into consideration, still the reality that all women have a slightly different cycle every next month, which influences the ovulation time as well as the fertility phase.
As a rule Calendar Rhythm Method is applied only as some additional safety measure, and only along with some other method of birth control.
Advantages of the Calendar Rhythm Method
• This method of birth control is considered to be rather simple, in comparison with other methods, such as applying a contraceptive patch or receiving hormone injections;
• Calendar Rhythm Method can be used by every healthy woman;
• There are no devices required in order to be able to apply this method of Fertility Awareness;
• This method of birth control interferes neither with foreplay nor with the very intercourse;
• The Calendar Rhythm Method is 100% reversible
Disadvantages of the Calendar Rhythm Method
• A woman has to spend a lot of time tracking her monthly cycles, before she can start using this method;
• It is not possible to start applying the Calendar Rhythm Method right away, as at there is a need to keep the track of woman’s menstrual cycles for at least half a year period;
• A woman’s husband or boyfriend may not be willing to cooperate, which may lead to complete failure of this method of Fertility Awareness.
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