Noun
natural family planning in which ovulation is assumed to occur 14 days before the onset of a period (the fertile period would be assumed to extend from day 10 through day 18 of her cycle)
Source: WordNetKippley, p.111 For these women, the rhythm method formula incorrectly identifies a few fertile days as being in the infertile period. Source: Internet
Even when used perfectly, calendar-based methods, especially the rhythm method, result in a high pregnancy rate among couples intending to avoid pregnancy. Source: Internet
Currently, many fertility awareness teachers consider the rhythm method to have been obsolete for at least 20 years. Source: Internet
Smulders published his work with the Dutch Roman Catholic medical association, and this was the official rhythm method promoted over the next several decades. Source: Internet
This is interpreted as favoring the then-new, more reliable symptoms-based fertility awareness methods over the rhythm method. Source: Internet
When used to avoid pregnancy, the rhythm method has a perfect-use failure rate of up to 9% per year. Source: Internet