Could precision medicine help women choose the contraceptive that works best for them?

It’s not unusual for my friends to ask my advice about birth control. I’m not a doctor, but as a public health practitioner at a global health NGO who works to achieve universal access to contraception, I live and breathe contraceptives.

That’s why my friend Amanda came to me in distress about a copper IUD, which she had recently begun using after a host of other contraceptive methods gave her headaches and nausea. She was in pain enough to miss work. Should she wait it out, she asked me? Or would it be best to have the IUD removed and dive back into the shrinking pool of available methods, hoping that another would stick?

I had nothing to offer Amanda other than reiterate what she’d already read and heard from her doctor: “Nobody knows how this will play out for you.”

It’s beyond frustrating that so many women and girls are blindsided by adverse effects associated with the current array of birth control choices. Not to mention the ambiguity about their effectiveness among women who are obese or those who take antiretroviral therapy to treat HIV.

Even with the pill — approved by the Food and Drug Administration in 1960 and widely used since — we’re offered a catch-all list of possible side effects and interactions. And while the same is true for many medications, contraceptives are distinct in that their use, almost exclusively by women, is globally widespread. Approximately 900 million women around the world use contraceptives. It’s a shame that, even with the best available evidence and resources, an unacceptable ambiguity about side effects is the standard.

It’s no surprise that the average American woman tries three different methods of contraception by age 40, and 30 percent try five or more methods by that age. At 33, I’m on my fifth.

In the places I work, sub-Saharan Africa and Asia, women experience similar side effects and dissatisfaction with their contraceptive choices. But it’s often challenging — and sometimes impossible — for them to consider changing methods, because of cost, or having to travel long distances for care, or waiting for months for a nurse to visit.

For a woman who wants to avoid unintended pregnancy, her threshold for tolerating unwanted side effects is forced to rise when alternatives are scarce. When the burden of side effects exceeds her tolerance she might, understandably, stop using contraceptives altogether. That could result in a host of bad outcomes, from being unable to safely space her children or dying from an unsafe abortion. Meanwhile, a fear of side effects also prevents some women from ever using contraceptives, and stops others from trying methods that might be more effective or more tolerable for them.

One thing many women want to know when considering a contraceptive method is how it affects menstrual bleeding. Research that aims to identify predictors of common side effects like that is limited. So clinicians and clients alike rely on averages and anecdotes from friends and family, and hope for the best.

In the next year, 10 percent of contraceptive users in low- and middle-income countries will stop using their method because of side effects and health concerns. Among women who aren’t using contraception even though they want to prevent pregnancy, around one-third cite concerns over side effects and health risks in their decision to not use it.

It’s time for more than grating reassurances; more than promises of new methods. It’s time for precision.

Personalized medicine could be the key. Pharmacogenomic research is starting to reveal how genetic differences influence people’s unique responses to specific medications. The FDA has assembled a list of 214 drugs with pharmacogenomic biomarkers in their labeling. While the oncology and psychiatry sections are relatively hefty (68 and 30 drugs each, respectively), there’s just one contraceptive, Yaz (drospirenone and ethinyl estradiol), on that list.

If pharmacogenomics tackles contraceptive drugs in a big way, users would be empowered to choose the right contraceptive options for them, the ones they can best tolerate. It would provide a definitive answer to “How will this play out for me?” rather than the shrug of shoulders most women receive.

Imagine if women everywhere had access to gene testing that could predict personalized benefits and side effects from each and every contraceptive method.

Imagine hearing from your doctor or logging in to a private portal to discover that a hormonal IUD will be 99 percent effective for you, and it will increase your appetite and stop your monthly menstrual periods. And that the pill will be 91 percent effective for you, and give you clearer skin.

Greater precision won’t cure any side effects from contraceptives, but it would dispel ambiguity about them.

While not yet a reality, applying precision medicine to choosing the right contraceptive is attainable given the pace of advances in individualized medicine. But the technology needs to be designed so it is within the reach of every one of the nearly 1 billion women who use, or want to use, contraception.

I can envision the results globally: Women everywhere choosing methods they can tolerate and stick with on the first try. Less precious time or limited resources wasted. Less disruption to their lives.

In the family planning community, our universal aim, our “gold standard” of client-centered care, is informed choice. I’d say our current version of informed choice is closer to a bronze standard.

With the alchemy of personalized medicine, we could get to gold.

Megan Christofield is a technical adviser for family planning at Jhpiego, a Johns Hopkins University affiliate.