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18th October 2017

Is “Natural” Contraception Right for You?

Consultant gynaecologist Miss Meg Wilson looks at how technology is helping women have a more natural approach to managing their contraception.

The idea of a ‘natural’ method of contraception is very appealing and a good option for many women, however it does require a bit of consideration as to whether it is the right choice for you.

There are many contraceptive apps available but ‘Natural Cycles’ is the first app to be certified as a recognised form of contraception in Europe (European Medicines Agency). It works by asking you to input your menstrual period dates and taking a daily temperature reading. It then uses a specially developed algorithm to determine which days you may be fertile. It will give you a green light on days you are not fertile and a red light on the days you may fall pregnant. On the red light days you will have to think about a backup method of contraception or perhaps not have sex at all.

Many women already use a ‘rhythm method’ for contraception as they can work out their ‘fertile window’ from their period dates, however doctors have been reluctant to advise the rhythm method as any miscalculation could potentially lead to an unwanted pregnancy. The additional information of temperature readings and the apps algorithm makes this a more reliable method and the evidence published so far is very encouraging. It maybe a good option for women who have not got on well with other contractive methods due to side effects or health problems. For some women the appeal is in a more ‘natural’ approach to contraception and a better way to understand their body and cycle. It has no side effects or need for prescription.

The most important question is “does it work?”. No contraceptive method, aside from abstinence, is 100% effective. If used perfectly the app has been found to be 99% effective, however few people use anything perfectly and therefore taking account of a bit of human error and a margin of error for the app getting the days wrong, it has been calculated that 6.8 women out of 100 may fall pregnant during one year of ‘typical’ use. To put this into context, ‘typical use’ of the contraceptive pill is reported that 9 women out of 100 may fall pregnant during one year.

One important to remember is that this method of contraception does not provide protection from sexually transmitted infections.

From a practical point of view, to use Natural Cycles effectively you need to be pretty organised and have a relatively regular daily routine. It costs £6 per month or £40 for a year’s subscription. Each morning, before getting out of bed, you need to take your temperature by placing a thermometer under your tongue and then type the reading into the app. This needs to be done at least 5 times each week. If you have a lie in for more than two hours to your normal wake up time, or you have a hangover you will have to add ‘skip day’ and miss the reading that day. The manufacturers advise you to leave your thermometer on top of your mobile phone as a reminder when you wake up each morning. If you give the app this regular information and have a regular menstrual cycle, you can expect to have about 60% green days each cycle, i.e.. if your menstrual cycle is 28 days long, you will get about 11 red days each month. If you have an irregular cycle or don’t enter enough temperature readings, you will get more red days as the fertile window is less certain. For your red days you will have to use an alternative method of contraception such as condoms. Women tend to give up using the app if they are getting a lot of red days.

In our view, Natural Cycles may be a good option for women who…
• Cannot take hormones for medical reasons or prefer not to take them.
• Are in committed relationships, don’t want to use condoms and are not at risk of sexually transmitted diseases.
• Women who have a regular daily routine and can commit to regular temperature readings.

Please get in touch if you have any questions or comments or wish to discuss your contraceptive needs.

Since writing this blog post, Natural Cycles is being investigated in Sweden after is was linked to 37 unwanted pregnancies  at a Stockholm hospital, it is also being investigated by the ASA as to it’s claim of being a “clinically tested alternative to birth-control methods”.  We advise using apps such as these with an element of caution.

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