What is the rhythm method?

The rhythm method is also known as the calendar method, periodic abstinence, or natural family planning. It is a method of contraception where you look at your menstrual cycle to see when you are least likely to get pregnant from having vaginal sex with a man.

Every menstrual cycle, a woman releases an egg (ovum) into her womb in a process called ovulation. If it is fertilised by a sperm, she becomes pregnant. If not, the egg is expelled from her body along with the lining of her womb: in other words, she has her period.

By only having sex when you know you are not ovulating, you can reduce your chances of getting pregnant. Alternatively, some women use a backup contraceptive such as a condom when they are ovulating. 

What are the pros and cons of the rhythm method?

The rhythm method has many advantages and disadvantages, some of which are outlined below:

If used consistently and correctly, the rhythm method is thought to be around 95% effective. However, in reality it is estimated that the rhythm method is 88% effective for most couples as it is difficult to keep to the method all of the time. This is much less effective than other methods of contraception such as condoms or hormonal pills.

How do I use the rhythm method?

To use the rhythm method, you should determine when your fertile period is and abstain from having sex during this period or use an alternative contraceptive. To do this:

1. Keep track of your next six to twelve menstrual cycles. The first day of your period is ‘day one’. Count the number of days until your next period, after which the cycle restarts. 
2. Take the number of days from your shortest cycle and your longest cycle. You will use these two figures to calculate your fertile period. 
3. Take the number of days from your shortest cycle and subtract eighteen, giving you the first day of your fertile period. For instance, if your shortest cycle is 28 days long, the first day of your fertile period is 28 - 18 = day 10. 
4. Then, take the number of days from your longest cycle and subtract eleven, giving you the last day of your fertile period. If your longest cycle is 35 days long, the last day of your fertile period is 35 - 11 = day 24. 
5. From those calculations, you now know to not have sex between day 10 to day 24 of your menstrual cycle or use an alternative contraceptive.

Sometimes, the rhythm method fails simply because a woman’s menstrual periods do not always follow the same pattern. The rhythm method is especially risky if you have irregular periods. Another reason the rhythm method fails in some women is that they haven’t tracked enough full menstrual cycles in order to accurately work out when their fertile period is. 

There are online resources available which allows you to track your fertile period through calendars and calculators. These can make it easier for you to keep track and use the rhythm method. 

Should I use the Pill instead?

Compared to the rhythm method, the Pill is more effective in preventing unwanted pregnancies. There are some disadvantages of the Pill compared to the rhythm method. For instance:

Anybody can get contraception from places such as GP surgeries, genitourinary (GUM) clinics, and sexual health clinics. To get the Pill, you will need to be assessed by a doctor who will be able to prescribe you the Pill, if it’s safe to do so. 

Additionally, you can order your Pill from online doctor services such as Superdrug Online Doctor.

I’m looking for some natural contraceptives

The rhythm method is suitable for people who do not want to or cannot use medicines or devices. For instance, this may be because:

• You are allergic to devices such as condoms

• You cannot use hormonal methods of contraception because of a medical condition

• You do not want to use modern methods of contraception due to cultural or religious beliefs and preferences

However, it is important to bear in mind that the average success rate for the rhythm method is 88%. If you have tried one form of contraception and do not like it, it may be worth seeing a health professional to discuss other options rather than switching to the rhythm method straight away.

Three natural alternatives to the rhythm method include:

• Symptothermal method

• Withdrawal (pulling out method)

• Abstinence

Symptothermal method - a good alternative to the rhythm method. This method works in a similar way: couples abstain from having sex around the time when the woman ovulates. However, the way that the woman works out her fertile period is different to the rhythm method. Women use several indicators to work out when they are ovulating:

• Basal body temperature

• Thickness and texture of the cervical mucus

• Breast tenderness

• Cramping

Alternatively, there are ovulation test kits available for some women who would like a little more help in using this method. However, the cost of these kits may be something to consider. See this guide on the symptothermal method for more information.

Withdrawal method  - another natural contraceptive that is around 82% effective. You may have heard of this method before, where a man removes his penis from a woman’s vagina before he ejaculates. However, this method comes with its own risks. Firstly, this does not protect you from contracting a sexually transmitted infection. Additionally, this method is not considered reliable even if a man consistently withdraws before he ejaculates. During sex, a man would release a small amount of lubricating fluid called the pre-ejaculate (precum) which may contain a small amount of sperm. 

Abstinence method - finally, some couples use this method when they do not want to become pregnant, where a couple do not have sex at all. This is the only contraceptive that is 100% effective in preventing pregnancy. It is important to note that some sexual activity such as mutual masturbation carries a risk of pregnancy if, for instance, sperm is transferred into the womb via your hands. So even if you avoid vaginal sex, you are at some risk of pregnancy from other types of sex.

I’ve just had unprotected sex. Will I get pregnant?

Sources

Case Western Reserve University (2010). Rhythm Method. Case Western Reserve University. [online] Available at: https://case.edu/affil/skuyhistcontraception/online-2012/Rhythm-method.html [accessed 4th December 2017].

Healthline Editorial Team (2017). Birth control: rhythm method (fertility awareness). Healthline. [online] Available at: https://www.healthline.com/health/birth-control-rhythm-method [accessed 4th December 2017].

Jones, R. K. (2009). Better than nothing or savvy risk-reduction practice? The importance of withdrawal. Contraception, Jun; 79(6). 407-410.

Stöppler, M. C. (2014). Natural birth control options. medicinenet.com. [online] Available at: https://www.medicinenet.com/natural_methods_of_birth_control/article.htm [accessed 4th December 2017].