Last Friday, the U.S. Food and Drug Administration (FDA) approved the first smartphone app for contraception, called Natural Cycles. Using your phone as birth control sounds pretty dope, especially in a world where our reproductive rights and access to contraceptives are under attack. But this birth control method is not foolproof, which is why it's also somewhat controversial.
How does this so-called birth control app even work? Each morning, you have to take your temperature using a special thermometer and enter the reading into the app. Natural Cycles' algorithm can then detect the slight spike in your basal body temperature (which is a sign of ovulation), and determine the days of the month when you're likely to be fertile, according to the FDA. If you're trying to get pregnant, Natural Cycles will alert you when to have sex based on this information, and if you're using it for contraception, the app will tell you when to abstain from penis-to-vagina sex or use protection. It costs $79.99 a year, and $9.99 a month to use the thermometer — no prescription necessary.
The temperature-based method is not that revolutionary, and there are a few similar fertility awareness birth control methods that people have been using for decades, like the "calendar method" and "the mucus method." They work by pinpointing fertile days in your cycle, and either planning sex around or during that window. But doctors generally don't recommend these techniques for contraception, because they're considered high-maintenance and therefore high-risk. For someone who is trying to get pregnant, fertility awareness methods might be a fit. But if you're using it as contraception, less so.
In a FDA news release, Terri Cornelison, MD, PhD, assistant director for the health of women in the FDA’s Center for Devices and Radiological Health said that "consumers are increasingly using digital health technologies to inform their everyday health decisions," so Natural Cycles can provide an effective method of contraception if it’s used right. But our familiarity and dependence on apps is also part of why Natural Cycles is not the best solution.
"We know that the millennial generation and the generation below them are very dependent on digital applications to sort of help run their life — that's a very normal and accepted concept," says Leah Millheiser, MD, FACOG, clinical assistant professor of obstetrics and gynecology at Stanford University. "However, I think in this case we might be a little bit misguided." With Natural Cycles, there's a lot of room for error, not to mention most young women don't have regular cycles to begin with, she says. If you forget to take your temperature (because you slept somewhere without your thermometer, for example), or you end up having sex on a "fertile day," then you could accidentally get pregnant, she says. And an app can't stop that.
Given how many other well-studied, reliable birth control options exist, Dr. Millheiser says she wouldn't recommend Natural Cycles to a patient. "This one leaves too much wiggle room for a mistake, especially in younger women," she says. According to the FDA, Natural Cycles has a "perfect use" failure rate of 1.8%, but a "typical use" failure rate of 6.5%, based on clinical studies on 15,570 women who used the app for an average of eight months. On the other hand, a copper IUD, which is a long-acting reversible contraceptive, has a typical use failure rate of 0.8%, and a hormonal IUD has a typical use failure rate of just 0.2%, according to the Centers for Disease Control. The pill has to be taken everyday, and still has a typical use failure rate of 9%, but it's also been around for longer.
So, is Natural Cycles right for anyone? "This is the perfect app for someone who doesn’t necessarily want to be on any contraception, and they’re not trying to get pregnant, but they also don’t care if they do," Dr. Millheiser says. Or if someone is allergic to all condoms, and has a sensitivity to all hormonal birth control pills, and all implants, then this could be a last resort, she says. Now with the FDA's approval, more people might see this as a smart option for contraception, which could be risky. Unless of course you're already using another form of birth control.