For women who have spent most of their reproductive years planning their lives around birth control — whether that means dealing with side effects from the Pill or scheduling doctor’s visits for IUDs, implants or shots — the idea of a hormone-free, noninvasive contraceptive might be alluring.
Today, some mobile apps promise exactly that. Earlier this month, Natural Cycles became the first FDA-approved mobile app for contraception. Although women have been using fertility-tracking apps to aid pregnancy efforts for years, a growing number of women are now using them to avoid unwanted pregnancy.
“Some patients are interested in contraceptive options that they feel are more natural and less likely to have side effects,” said Dr. Allie Linton, an ob-gyn at Children’s Hospital of Wisconsin and Froedtert Hospital and a professor at Medical College of Wisconsin. “Some women wish to avoid hormones altogether, and others dislike the idea of using a contraceptive device such as an IUD or implant.”
Using a mobile app in lieu of popping a pill or inserting an IUD might sound good on paper, but apps aren’t a fit for everyone. Here’s what to know if you’re thinking of making the switch to a contraceptive app.
How does Natural Cycles work?
Natural Cycles uses an algorithm to monitor your cycle by analyzing daily basal body temperature readings, meaning your lowest at-rest temperature. Users take their temperatures first thing in the morning before getting out of bed and record their data in the app. According to its creators, the algorithm also factors in sperm survival, temperature fluctuations and cycle irregularities. Based on that information, the app tells you whether it’s a green day — when you’re not fertile and it’s safe to have sex — or a red day, when you’re at risk for pregnancy and should either use protection or abstain from sex.
If this idea sounds familiar, that’s because Natural Cycles is a digital version of fertility awareness–based birth control, sometimes referred to as natural family planning or the rhythm method. The rhythm method has long been championed by the Catholic Church, but it’s often dismissed by critics as a game of “Vatican roulette,” a nod to the relatively high failure rate of fertility awareness–based birth control.
The American College of Obstetricians and Gynecologists reports that fertility-awareness methods are some of the least effective at preventing unwanted pregnancies. They have a 24-percent typical use failure rate, meaning an average of 24 women out of 100 accidentally become pregnant during their first year using that contraception method. By comparison, the typical use rate for the Pill is 9 percent and between 0.2 and 0.8 percent for IUDs. The Natural Cycles app also faced a backlash recently after 37 women in Sweden became pregnant while using it.
However, a study of more than 22,000 women using Natural Cycles (funded by the company) found a typical use rate of 7 percent, putting it on par with hormonal birth control pills. To some experts, those numbers are promising.
“The big thing with being able to establish safety and efficacy is to have enough data that’s reliable,” said Dr. Joseph B. Davis, a fertility specialist and assistant professor of obstetrics and gynecology at the Icahn School of Medicine at Mount Sinai in New York City. “The company went through a lot of effort to show the actual benefit of it.”
Who’s a good candidate for the birth control app?
After taking birth control pills for nearly 15 years, Holly, a 29-year-old marketer in Los Angeles, wanted a break. When she went off the Pill, she started using two apps in conjunction: Natural Cycles and the period-tracking app Clue.
“I didn’t want to take hormonal birth control anymore. There were just too many bad side effects,” she said, adding that the anxiety she experienced during the Pill’s placebo weeks was worse than typical PMS symptoms. “I felt like it was affecting my mental health.”
For women who experience unpleasant or upsetting side effects on hormonal birth control, an app like Natural Cycles might be a worthwhile alternative. The app might also appeal to women who are allergic to the copper used in the nonhormonal ParaGard IUD.
Aside from avoiding the pill’s side effects, Holly liked the idea of switching to an app to “make sure things were working” in case she wanted to have kids one day. Women who are planning to start a family soon may be especially good candidates for Natural Cycles, Davis said.
“That might be a really nice transition,” he said, “because they can come off the hormones, get cycles back to regularity and still postpone pregnancy as long as they want to use the app.”
Compared to other forms of birth control, the app requires a lot of legwork. The ideal user is someone who’s motivated to follow the app’s instructions to a T and can consistently record temperature readings at the same time each morning.
Before deciding if it’s a good fit, you should fully understand the limitations of the app and the steps required to avoid pregnancy, which include practicing abstinence or using barrier-method contraception like condoms during ovulation. The ideal candidate also has regular menstrual cycles. Women transitioning off hormonal birth control might have irregular periods for a while, which could compromise the app’s accuracy or result in more red (no-sex) days. Adolescents and women nearing menopause tend to have irregular cycles and might not be good candidates for the app.
Who should think twice before switching to a birth control app?
If you have irregular cycles or experience amenorrhea (absence of periods) while on hormonal birth control, an immediate switch to the app may not be entirely effective. Natural Cycles says it takes around one to three cycles for the app to “get to know you,” so you may have more red days in the beginning. If your periods were irregular before starting hormonal birth control, you may find that they’re still erratic after you come off the hormones, making it harder for the app to predict your cycle.
Women should also consider whether an app fits their lifestyle. If you wake at a different hour every morning to accommodate an erratic work schedule, or if you tend to sleep in on the weekends, you may find it more challenging to enter consistent temperature readings than a woman with a rigid daily schedule. Natural Cycles also warns that sickness and hangovers can affect your temperature, which can lead to more red days during a given cycle.
The bottom line
Ultimately, fertility awareness apps like Natural Cycles could be a good option for women who are able and willing to take consistent, daily temperature readings, women with predictable menstrual cycles, women planning to start a family soon or women who are avoiding hormonal birth control for personal or medical reasons.
But if an unplanned pregnancy would be catastrophic, you’re better off using contraceptives with a higher success rate, like an IUD.
“I support giving women as many options as possible,” Linton said. “That said, it is important for women to know that if pregnancy prevention is their primary goal, we have methods of contraception that are more effective than Natural Cycles.”