Calendar method
This method is also known as the “Ogino method” or “fertility calculation”.
How it works: identify the moment of ovulation by observing the menstrual cycle for at least 6 months. This period ensures that the observations are representative of the person’s menstrual cycle.
- This method may be easier for people with a regular menstrual cycle. However, it presents difficulties for two main reasons:
- Irregular cycles: Most people have irregular menstrual cycles, which makes it difficult to determine the precise moment of ovulation.
- Coordination with the‧a partner: both partners should agree to avoid unprotected intercourse during fertile periods or use an additional contraceptive method, such as condoms.
Efficiency: Typical use: 80%, perfect use: 91-99%.
Benefits
- Uterus-controlled method
- Free and always available
- Does not affect hormonal system, cycle length or blood flow
- Gives you a better understanding of your cycle and your body
- Does not limit the spontaneity of sexual relations
- Promotes communication and collaboration between partners
- Suitable for people with moral or religious concerns about other contraceptive methods
Disadvantages
- Requires several months’ observation of the menstrual cycle before application
- Requires a regular menstrual cycle, which limits its use
- Events such as stress, overwork or illness can affect reliability
- Not recommended during periods of cycle disturbance (post-partum, breastfeeding, after miscarriage, approaching menopause, after stopping hormonal contraception).
- Limits intercourse with vaginal penetration to periods of infertility and requires an additional method during fertile periods
FAQ
How to calculate the risk period for pregnancy using the calendar method?
To calculate the period at risk, you need :
- Estimate ovulation date.
- Identify high-risk days and avoid sexual relations during this period, or use another method of contraception.
To determine the abstinence period :
- Subtract 18 days from the longest menstrual cycle.
- Subtract 11 days from the shortest menstrual cycle.
For example, for 26- to 29-day cycles, avoid intercourse from day 8 (26-18) to day 18 (29-11) of each cycle. The first day of menstruation is Day 1.
Is this method effective?
This method allows you to control your fertility, but it can be difficult to precisely identify the period at risk, which can affect its effectiveness.
Are there mobile apps to use this method?
Yes, several mobile applications can provide a calendar and estimate the date of ovulation and menstruation. They provide quick access to information. A paper calendar can also be used to mark important dates.
Sources: Ça se planifie. A guide to choosing the right contraception, on The Society of Obstetricians and Gynaecologists of Canada (SOGC). Available at: https: //www.caseplanifie.ca/ (consulted on 08-2024).
