Long before the pill, even before condoms, women have tried to exert control over if and when they get pregnant. The method of tracking fertility has existed in some iteration for centuries, but wasn’t widely practiced until the early 20th century. It’s a natural method of birth control where a woman tracks when she’s most likely to get pregnant using a calendar, body temperature, and cervical mucus (or a combination of all three). On a scale of jumping up and down post-coitus to abstinence, it falls somewhere in the middle.
The failure rate for fertility awareness is 24%, according to the CDC, which means 24 out of 100 women who use it in a typical fashion (i.e., not perfectly) will get pregnant each year. (Not great odds.) For comparison, IUDs, hormonal birth control pills, and condoms have a failure rate of 0.2% to 0.8%, 9%, and 18%, respectively. Unless you are someone who maybe, possibly would be okay with getting pregnant, the conventional wisdom has been: Don’t go the natural route.
This stance appears to be subtly evolving, in large part because what was once left to ad hoc thermometers and charts has been digitized. Over the past couple years, a number of apps that track and chart women’s fertility cycles have launched. Their use cases and techniques vary, but many proport to tell users when they can and can’t get pregnant. The majority are marketed to women who simply want to track their menstrual cycles or who are actively trying to conceive, but the ability to reduce the risk of getting pregnant hangs there, too.
Reducing The Risk (And Cost And Side Effects)
Natural Cycles takes this implicit use case and makes it explicit. Launched in 2014, the company bills itself as “an effective method of contraception.” Using fluctuations in temperature (it sends users branded thermometers) and information from past cycles, the app divides the calendar into fertile (red) and infertile days (green). Sperm can survive in the body for close to a week, which means sex before ovulation can result in a pregnancy. “We find those days for you,” the website assures. The app costs $9.99 a month, or $79.99 a year.
The company says its typical use efficacy rate is 93% (which means a total of 7 out of 100 women would get pregnant during a year of use), a claim it backs by pointing to a prospective study of 22,785 women who used the app over the course of roughly 10 months. (More on this later.) Earlier this year, it was certified as a method of birth control by the European Union, and last month, it raised $30 million in Series B funding.
Olivia Kraft, 24, first heard about the app through a Facebook ad. The timing was fortuitous: Kraft was already thinking about going off hormonal birth control pills, which she’d been prescribed at 14 to help regulate her period. “I was tired of taking them,” she says. “My PMS was always really bad, and I wondered if it would be different if I wasn’t on the pill.”
She was encouraged to see the company had conducted clinical trials. “I did my own research,” she says. Besides, the underlying premise made sense to her: “Women track their temperature to conceive, so why couldn’t you reverse it to prevent a pregnancy?” She discussed it with her fiance, and they’ve been using the app successfully since June.
Like Kraft, Vicky Richings, 40, a yoga teacher who lives in the U.K., was already searching for alternatives to the pill when a friend told her about the app earlier this year. On and off the pill since she was a teenager, over the years she’d grown more concerned about side effects, particularly research that has linked it to depression and certain cancers.
While she’d previously viewed natural birth control as a method “for people who want to get pregnant,” she was impressed by the app’s efficacy rate and decided to give it a try. For the first three months, there were more red days than green days, but as the app collected more information on her cycle, the green days began to outnumber the red. A self-described geek, Richings was already using a Fitbit to track her sleep, so remembering to take her temperature each morning was easy. (For the less data-inclined or anyone with an erratic sleep schedule, it would be a more difficult adjustment. The app works best when users get a similar amount of sleep each night and take their temperature at the same time each morning.) Skeptical friends and family still bombard her with anecdotes–everyone has knows someone “whose aunt used a similar method and got pregnant”–but she’s happy to be off the pill (no more hormones and, so far, no pregnancies).
Hannah Ransom, 32, has made a career teaching women how to transition off hormonal birth control. A certified fertility awareness educator, she focuses on the sympto-thermal method, which combines the calendar method (tracking your most fertile days), the basal body temperature method (tracking temperature spikes that accompany ovulation), and the cervical mucus method (tracking the changes in color and consistency that signal ovulation) to determine when the body is fertile. Because it incorporates so many data points, when used correctly, its efficacy rate is significantly higher than other fertility awareness methods. “There’s been a lot of research on this method. It’s quite established as effective if women use it properly,” says Dr. Victoria Jennings, director of the Institute for Reproductive Health at Georgetown University, who is working on a competing birth control app call DOT.
Ransom’s message isn’t that the method is right for everyone. There are too many serious limitations, including a steep learning curve and the need to diligently track multiple data points (a lot more complicated than remembering to take a single pill daily). But she wishes it was presented to women as a viable option, rather than a fringe alternative.
But Does It Really Work?
You’d think Ransom would be glad to see a company like Natural Cycles burst onto the scene. With 600,000 users, including 100,000 who are based in the U.S., it’s doing an impressive job marketing the fertility awareness method to younger users.
So I was surprised to find the app makes her wary. Her main concern is that the company has yet to conduct a randomized control trial, in which individuals are randomly assigned to treatment and control groups. Considered the gold standard for validating new devices and drugs, they allow researchers to directly compare treatment outcomes.
Natural Cycles’s 93% efficacy claim comes from a large-scale study in which it analyzed user data over the period of roughly 10 months. Because participants were all women who chose to sign up for and use the app, they might share characteristics that don’t translate to a wider population, says Dr. Jennifer Conti, a clinical assistant professor of obstetrics and gynecology at Stanford University School of Medicine. (In an email, Natural Cycles cofounder Elina Berglund said the app is “best suited for women with a rather stable lifestyle, who are in committed relationships.”) Given these constraints, Dr. Conti is skeptical that it’s a good fit for many of her patients. Chronic stress, sleep deprivation, and diseases such as obesity and diabetes, all common facets of life in the U.S., can result in irregular periods.
Jennings would have also preferred that the company conduct a randomized control trial before making any efficacy claims. “I imagine that Natural Cycles is effective, but based on the available research, I really don’t know,” she says. “It’s a black hole for me.” According to Berglund, the company is considering conducting a randomized control trial, but stressed the results from the existing studies are just as valuable as they provide “real life results.”
A Product Of The Times
No method of birth control is perfect. There are always tradeoffs and mental calculations (around effectiveness, access, cost, lifestyle, side effects) to be reckoned with.
For doctors and educators, it’s much the same. How do you ensure women are informed about the options available to them without discounting their preferences and minimizing their emotions? From Ransom, Jennings, and Conti, I sense a carefulness bordering on weariness. After years of inflammatory messaging and scare tactics around birth control, they remain on alert. “The biggest reason I think people see fertility awareness as horrible is they’re afraid it will be forced on people,” Ransom says. When the Trump administration rolled back the mandate requiring insurers to provide birth control, there were reports that the administration wanted to increase funding for fertility awareness.
Politics is a powerful source of anxiety, but it’s not the only one. In response to a recent study that linked hormonal birth control, including IUDs, to an increased risk of breast cancer, Conti has been thinking about what to tell worried patients. “Most headlines haven’t represented the research very well,” she says. (The risk, while real, is small, and the pill has been shown to lower the the risk of developing ovarian, colon, and uterine cancer.) Her goal is to contextualize the link for her patients, while remaining sympathetic and receptive to their concerns.
A new category of apps making unvalidated health claims makes what is already a complicated and contentious topic even more complex. Technology covers the messy, unpredictable statistics inherent in most contraceptive methods with a sheen of infallibility. “If you are writing something on paper, that’s old-fashioned. But if it’s on app, it must be right,” Jennings says. Both she and Conti worry companies will benefit from this logic, regardless of whether their claims are supported by actual evidence. In a field of apps, Natural Cycles is one of the few to have conducted peer-reviewed clinical research. While popular fertility tracking apps like Eve by Glow, Clue, and Kindara don’t market themselves as contraception methods, that doesn’t stop women from using them to determine when they can have sex without a condom.
Every person I spoke with for this article said they want women to have access to more information and options around sexual health. “We want every woman to know how her body actually works,” Berglund wrote in an email. “It’s time to give back the control to the women.” Jennings wants this too, but in the form of better data and more clinical research.
As for Richings, the yoga instructor in the U.K., she picked Natural Cycles after weighing all the options available to her. If she were to get pregnant today, she has the resources to make an informed, responsible decision. That wasn’t always the case, and she suspects as a teenager or a twentysomething, Natural Cycles wouldn’t be the right method of birth control. “But it’s always nice to know there are alternatives,” she says.
Correction: A previous version of this article failed to mention that Dr. Victoria Jennings, is working on a competing birth control app.
Laura Entis is a freelance writer and editor based in Brooklyn. She has written and edited for publications including Fortune, Entrepreneur, Racked and the Guardian.