kalenderrytmetoden

The kalenderrytmetoden, often translated as the calendar rhythm method or rhythm method, is a natural family planning technique used to prevent pregnancy. It relies on tracking a woman's menstrual cycle to identify fertile and infertile days. The core principle is to abstain from or use barrier methods during the fertile window, which is the period when pregnancy is most likely to occur.

To implement the kalenderrytmetoden, a woman monitors her menstrual cycles over several months, typically six to twelve. She records the length of each cycle, noting the start and end dates of menstruation. Based on these records, she calculates her estimated fertile period. This calculation usually involves subtracting 18 days from the length of her shortest cycle to estimate the start of her fertile window, and subtracting 11 days from the length of her longest cycle to estimate the end of her fertile window. Intercourse is then avoided during this calculated fertile period.

The effectiveness of the kalenderrytmetoden is generally considered lower than that of other contraceptive methods. Its success depends heavily on the regularity of a woman's menstrual cycle and the accuracy of her tracking and calculations. Irregular cycles can make it difficult to predict the fertile window reliably. Factors such as stress, illness, or changes in routine can also affect cycle length and ovulation, further reducing the method's reliability. Consequently, it is not recommended as a primary method of contraception for those who need high protection against pregnancy. The method also does not protect against sexually transmitted infections.