The Calendar Based Method of Family Planning is a contraceptive method that aims to prevents unwanted pregnancy without the use physical barriers like condoms. Using this method, the time to engage in sexual intercourse is determined by monitoring the woman’s period, and thus understanding when she is least fertile, and when she is most fertile/productive. If you are a woman planning to use this method, then you can track your menstrual cycle for six months to a year. This will give you an idea about which days you are fertile, and which days you are infertile. You can then avoid pregnancy by having sex only during those days of infertility.

What is the basis of this method?

The lifespan of an egg or ovum is short. Many things need to fall into place at the same time for a normal fertilization. The fertile period for any woman doesn’t last more than 5-6 days. Even within that period, when the egg is released from the ovaries, if it doesn’t get fertilized by male sperm within 24 hours of its release, it will run down through a vaginal opening in the form of menstruation. The egg, after it’s release, travels through the fallopian tube; and if there is male sperm present which can fertilize the egg, then the woman conceives. So to avoid unwanted pregnancy, you need to avoid intercourse during this 5-6 day period.

Another thing which is the life of sperm is generally of five days, and it can remain there in the fallopian tubes for these numbers of days. So, if you had unprotected intercourse 4-5 days before your ovulation, then there are chances of getting pregnant as well. So you not only need to take care during the 5-6 days of your most fertile period but also 4-5 days before the same.

How does this work?

The calendar based family planning methods help the couple roughly determine when the women will ovulate and when she will be infertile. This knowledge can be used to avoid having sexual intercourse on those days, or opting for alternative contraceptive methods for those days. A woman is highly fertile right after ovulation, when the egg is actively seeking a sperm. But after these few days of fertility, the ovum disintegrates, marking the end of the period of fertility. So after this phase and before ovulation is a phase when the chances of getting pregnant are theoretically nil.

The studies show that the majority of women having a normal menstrual cycle of 28-32 days have their ovulation during the middle of the cycle, within the range of 4 days. So, if you are have your periods on the 1st of the month, then the midpoint of your menstrual cycle would be around 14th-15th, and your ovulation would most likely occur between 12th to 17th. This similarly applies to other cycles during other months.

So if you want to use this natural birth control procedure, then you need to understand and work out the midpoint of your menstrual cycle. By chalking out the midpoint, you can easily understand when you are fertile and are at risk of conceiving. Thus, by using alternative contraceptives or avoiding intimacy with your partner during that period, you can avoid an unwanted pregnancy.

There are two variations of the Calendar Based Method, which are described below:

1) Standard Days Method
This method is for women who have their menstrual cycle on a regular interval, without much variation. This method is best suited for women having a menstrual cycle of 26-32 days.

2) Calendar Rhythm Method
For women who have an irregular period typically less than 26 days or more than 32 days, the Calendar Rhythm Method is recommended.  This approach, instead of considering a standard menstrual cycle, instead counts the fertile and the infertile days depending on the individual cycle of the woman. In this case, the woman has to be diligent about tracking her cycle for six months in order to fully understand and map it. There are apps available that can help with this task.

Pros and Cons of Calendar Based family planning method

Pros

• This is a natural method of family planning, and thus has no side effects, unlike contraceptive pills.
• It doesn’t cost anything, other than time and effort. There is also no requirement of any additional tool or device.
• Women get to understand their body, and their menstrual cycles, a little more, which can generally prove beneficial to their health in the long run.

Cons

• Not all women can accurately monitor their menstrual cycles, which severely undermines the effectiveness of this method for them.
• Standard day method cannot be used for women having irregular periods.
• To be 100% safe from pregnancy, the couple might still need to use alternative contraceptive methods.
• This method is only 85%-88% effective.
• This method cannot protect one against any Sexually Transmitted Infections.

For those hesitant to use other contraceptive methods for various reasons, the Calendar Based Method is their best bet when it comes to avoiding an unwanted pregnancy – with the added benefit of having no side-effects that can adversely impact the woman’s reproductive health.