Imagine a future in which a woman becomes fertile only when she wants to become pregnant. Accidental pregnancy has faded into history, and the thought of a child coming into the world unplanned is startling.

In other words, in this future, surprise pregnancy is actually surprising.

Today, half of U.S. pregnancies are accidents–either mistimed or unwanted by the woman’s own report–and this future sounds like a distant dream. In half of these cases, the woman was using some kind of contraception in the month she got pregnant. Unmarried women between the ages of 18 and 29 describe seventy percent of their pregnancies as unintended! Births to U.S. teens are higher than any other country developed country, and over half of girls who give birth as teens drop out of school.

But thanks to a revolution in contraceptive technology, it doesn’t have to be this way. The latest generation of birth control technologies–state of the art IUDs and implants–are making our imagined aspirational future a reality.

A Woman’s Forty Year Fight. Fertility can be thought of like a light switch. At puberty, nature flips the fertility setting to “on.” Then, for almost forty years straight, a woman’s body prepares each month for a pregnancy whether she wants a baby or not.

Today, globally, over 220 million women would prefer to delay, space or limit child bearing but have no modern means to manage their fertility, but even women who are lucky enough to have modern contraceptives still struggle to keep fertility switched off consistently. Hormonal birth control methods like the Pill or shot turn fertility off temporarily, but then, after a day or a few weeks or months, it flips itself back on. And women–especially young women whose lives may be chaotic or unpredictable–find their best intentions thwarted by the complexities of everyday life: forgetting, finances, fights. You name it.

With perfect use the Pill is 99% effective, but are you perfect? Do you know anyone who is? Next to nobody can remember to take the pill at the same time every day for forty years straight. And next to nobody uses the condom perfectly for years on end. Pills and condoms have a 100% predictable, baked-in failure rate, because real live human beings are part of the equation. Women typically miss several pills per month, even when they are trying really hard, even when they send themselves text message reminders. In fact, only 15 percent of women miss less than three pills per month. Imagine if automobile brake pedals were made so that your foot slipped off that often. The folks who make a living doing “human factors engineering” would get fired.

Every day and every time birth control methods simply aren’t optimized for the human animal–for real people living in the real world. Consequently, on the Pill, which is 1960’s technology with minor tweaks, one in nine women gets pregnant each year. (For couples relying on condoms, the pregnancy rate is almost one in six; with no birth control it’s over eight in ten.) Who knew?!

Whoops Proof. What is the solution? Long-acting “get it and forget it” contraceptives that take human error out of the equation. In contrast to methods that require impossible perfection, long acting IUDs and implants are “whoops proof.” For a woman with a top-tier IUD or implant, unintended pregnancies drops below one in five hundred. Teen pregnancy and abortion totally tank.When it comes to preventing pregnancy, these methods are as good as sterilization, and yet fertility can be restored by a five minute procedure and returns within a few cycles.

The primary reason they are so much more effective than older contraceptive technologies is the default factor, the question of what happens if you do nothing. If a woman forgets or runs out of money temporarily or makes a mistake or is raped, is her fertility switch “on” or “off?”

Long acting contraceptives toggle the default setting. They flip the fertility switch to “off” for years at a time, making pregnancy opt-in rather than opt-out. The implant Nexplanon is good for up to three years. The Mirena IUD, which releases a micro-dose of hormone, is good for five to seven. The copper Paragard IUD is good for at least twelve. Getting a long acting contraceptive is more hassle and expense than getting a pill pack or box of condoms. It requires a medical procedure; no one technology works for everyone; and sometimes the first one isn’t a fit. But once it is settled in, the expense and hassle of monthly or daily or every-time-you-have-sex contraception is over. The experience is “get it and forget it.”

Choose your period. If that wasn’t enough, some long acting contraceptives have bonus health benefits, including a side benefit (formerly thought of as a side effect) that radically improves the lives of many women: they reduce menstruation. In 2009, the FDA approved the Mirena IUD to treat problem periods. Hormonal IUDs reduce bleeding by on average 90%, completely eliminating periods (and cramps, bloating, anemia and related menstrual morbidity) in most users by the second year. Implants and injections also can be “bleed free.” One Seattle family planning provider asks every woman who comes through her door: “How often do you want to have your period? Once a month, once every few months, or never?”

For women who are plagued monthly with cramps or nausea being able to reduce symptoms is a godsend. American women miss over 100 million hours of work annually because of menstrual symptoms. But even for women with milder periods, less may be better. Growing evidence suggests that modern women may experience more menstrual bleeding than is optimal from a health standpoint. We have four times as many periods as our hunter gatherer ancestors. What has been called the “incessant ovulation” of modern women causes chronic anemia and may have more severe lifetime effects including increased risk of cervical, uterine and breast cancers, and osteoporosis. More and more women are opting to regulate their periods by using continuous birth control pills, but this requires that they keep their entire bodies flooded with hormones, in contrast to the micro-dose released locally by an IUD.

The U.S. population includes 65 million women of reproductive age. Most of these women either aren’t ready to start families or already have as many children as they desire. And yet they continue ovulating and bleeding each month for close to forty years. Young millennials vent their annoyance via wry commentary, “Why Periods Suck” for example at Tumblr or Twinklex or Facebook. Hundreds of older women have posted more painful tales of woe at the online Museum of Menstruation (mum.org). To the question, “Would you stop menstruating if you could?” responses fall two to one on the yes side. In an international study of over 4000 women who had a hormonal IUD, 55 percent stated that preference for shorter lighter periods was a factor in their contraceptive choice.

Jump the Information Gap. In the U.S., young women who have not yet started families are only beginning to use IUD contraception thanks in part to an information gap. The World Health Organization, Centers for Disease Control, and American College of Obstetricians and Gynecologists all are convinced that modern IUDs and implants offer the top tier of efficacy and safety for women including teens and even those who are HIV positive.

But FDA approval lags behind international trends and research. Until 2005, the copper Paragard was approved only for monogamous women with children. The agency first approved a hormonal IUD for childless women in 2012, three decades after the technology first hit the market in Finland. Many busy primary care doctors have yet to get the word that practice standards are changing. Some unknowingly perpetuate outdated patterns and anxieties. Misinformation in the medical community translates into misinformation among members of the public.

Demand Better. There’s lots of room for improvement. In a study of 100 post-partum teens, half were given an implant and half the pill. At the end of a year, 20 were pregnant again in the Pill group but only 1 in the implant group.

American women are ready for change. IUD use in the United States is dramatically low compared to other developed countries. Currently 26% of Norwegian female contraceptive users have an IUD, but only 10% of Americans do. And yet, the U.S is showing a rapid shift in recent years. From a low of 1.3% of U.S. women using any kind of IUD in 1993, prevalence jumped to 2% by 2002 and then to 5.5% between 2006 and 2008 to 10% today. With FDA approval of Implanon in 2006, approval of the Mirena for menstrual symptoms in 2009, the Skyla IUD in 2013, Liletta in 2014, and a long acting Ring in the pipeline, we are on the cusp of a contraceptive revolution that has the potential to revolutionize our lives.

Read more on contraception by this author:

New Contraceptives for Cascadia–The Lesson of St. Louis
Dramatic Drop In Teen Pregnancy Really a Technology Tipping Point
Pamper, Pamper, Pamper – Plus 9  Other Tips for Falling in Love With Your IUD
A Brief History of Your Period and Why You Don’t Have to Have It
Hey Ladies!  Thinking About Ditching Your Period?  A Doctor Answers 12 Puzzling and Hopeful Questions
The Big Lie About Plan B – What You Really Should Be Telling Your Friends