Digital contraception is coming

The much-hyped digital contraceptive app, Natural Cycles, has come under fire this summer. Mounting controversy surrounds its claims and its advertising, but the US Food and Drug Administration have approved it as a form of contraception, following similar approval by the European Union. After all, women have been doing this without technology for millennia. Fertility tracking is an excellent way to avoid pregnancy without artificial hormones flooding your body—abstain from sex or use protection when you’re ovulating. Simple. Except, there’s no way of predicting ovulation with 100 percent accuracy.

Menstrual cycles are fickle beasts involving multiple hormones that are affected by myriad outside influences, including stress levels and body fat percentages. Cycles are rarely consistent; simply tracking 28 days from the start of your last period is not enough to accurately predict anything. You can use other data including your levels of luteinising hormone, the thickness of your cervical mucous, and daily basal temperature—which is what Natural Cycles tracks—but these are all subject to human fallibility. The strips to test your urine for the luteinising hormone must be used first thing in the morning and even if you manage that every day, you need to understand fertility and ovulation occur at separate times.

Your fertile window is four to five days before ovulation, while the test strips signal when ovulation is roughly 24 hours away; a negative indicator on the strip four to five days before you expect it is not the go-ahead to have unprotected sex. So you need to test your urine at the same time every morning (sayonara weekend liein)—the same time at which you’re supposed to take your oral temperature for the Natural Cycles app. Logging this every day allows the app to learn the patterns for your ovulation cycle as ovulation causes a slight rise in basal body temperature, which is most accurate first thing in the morning—unless you didn’t sleep very well, have an infection, have a hangover, feel stressed, or got up in the middle of the night to get a glass of water. It can even be affected by how many hours of sleep you got, and Natural Cycles does recommend against logging your temperature over the weekend—this raises two questions.

How can you get a 93 percent accuracy rate for your temperature changes over time, and what if you don’t have that kind of stability in your life?

Every form of contraception has an ‘ideal’ user; those on the contraceptive pill need to be regimented about taking their pill at the same time every day, while those with the implant are more suited to a ‘put it in and forget about it’ approach. For the Natural Cycles app, you need to be regimented at taking your temperature every day, with a very stable lifestyle—and you need to want to have children. What’s the definition of contraception again? The founders of the app describe their ideal user as a woman who is planning to have children at some point, and would like a break from hormonal contraception before trying, saying it’s not a good option for women who want to entirely avoid pregnancy. This is not the message that comes across in Natural Cycles’ marketing.

But this is not an article condemning the failings of an app; it’s not an article about the difficulties faced by women around the world simply trying to have sex and not get pregnant. Rather, let’s look to the future; what could make a calendarbased, non-hormonal contraceptive effective for every woman?

The Natural Cycles app is a great start. Female health technology is booming with an estimated $1 billion of investment raised worldwide in the last three years.

Hormone-free, non-invasive and easy to use— it’s definitely on the right track. The app does the work for you, handling all the data and the calculations, which may be where normal women slip up when tracking their fertility on a traditional calendar. And that’s the catch—being normal. The average woman looking to avoid pregnancy is not the woman targeted by Natural Cycles. Who has the level of stability assumed by the app’s creators? Who isn’t stressed sometimes (or all the time); who doesn’t get sick every now and again; who doesn’t drink one, two, or three too many on occasion? Who manages to charge their phone every night without fail and who hasn’t misplaced something? You need to keep that thermometer on your bedside table and reach for it immediately upon waking—move even the slightest bit (say, going in search of a thermometer you could have sworn you’d left there the day before), and your accuracy rate will drop. And on that note, who sleeps exactly the same amount every night? The average woman is not going to achieve the 93 percent accuracy rate Natural Cycles touts—she’s more likely to get the 76 percent rate seen with normal calendar planning.

Even then, Natural Cycles doesn’t protect you from pregnancy. It can only tell you when you’re at risk of getting pregnant—if anything, it works best as an alarm bell for condom sales. At the moment, that’s the best way to use digital contraception; if you lack the discipline needed, let the app warn you when you need to use additional protection. It’s better than using condoms all the time, or adding artificial hormones to your body if that’s what you’re trying to avoid.

We’re standing on the precipice of a revolution in healthcare.

Personalised approaches to health are the future, and they’re just around the corner. Nonhormonal contraception is being digitised with great potential. Consider the efficacy we could achieve if we had an easier way of measuring temperature every morning, at exactly the same time; or the levels of luteinising hormones circulating in our body at any moment; or even the split second an egg is released.

There are some more invasive solutions to the tracking dilemmas; could an implant be used, not to release hormones into the blood stream, but to measure and transmit data to a smartphone? Could something similar sit unobtrusively in a fallopian tube and signal when an egg passes it by? Could a chip live under the tongue and take note of our basal temperature every morning at 6am without us having to do a single thing?

Diabetes sufferers are experiencing a similar boom in the technology available to them. Rather than pricking their fingers to measure blood sugar levels, small sensor patches can be worn on the arm to measure glucose levels in the interstitial fluid between the cells under the skin. The measurements aren’t as accurate, true, but patients can monitor their levels continuously and wirelessly with a tap of their phone. Eversense is a subcutaneous implant that measures glucose and transmits data in real time—and also now has FDA approval. Similar technology for female contraception is hardly beyond the realms of possibility. ■