Preventing unwanted pregnancies: Forget sex ed and compare the pill to IUDs.

What’s the Most Effective Method of Contraception, by Far?

What’s the Most Effective Method of Contraception, by Far?

Health and medicine explained.
July 31 2012 11:30 AM

Why Have Teen Pregnancy Rates Dropped?

A new study shows how to reduce them even more.


Photograph courtesy of iStockphoto/thinkstockphotos.

Something quite remarkable has happened to teenage pregnancy rates in the past few years. They’ve reached a three-decade low, down by 40 percent since 1990. Teen births and abortions also have fallen respectively by one-third and one-half.

Better sex education, though a sensible practice, doesn’t deserve the full credit. Teen pregnancy is often blamed on some states’ promotion of school-based “abstinence-only” education, which neglects contraception. But the recent drops in teen pregnancy were present across the country, in states with comprehensive sex education (like New Jersey, where annual teen pregnancy rates dropped from 11 percent to 7 percent) and those without it (like Texas, where the rate is higher but fell by about the same relative amount). The Centers for Disease Control and Prevention reports that 40 percent of teens didn’t use a condom at last intercourse, and that sorry figure doesn’t vary much by state. And between 1995 and 2010, depressingly, the substantial percentage of teens who used no contraception at all remained unchanged nationwide, indicating that teens didn’t suddenly start using birth control.

Part of the explanation is that teenagers are waiting longer to have sex. According to federal surveys of teenage girls, 49 percent reported they were virgins in 1995, but 57 percent said they were in 2010. (The trend was even more pronounced among black teens, whose rate of abstinence rose from 40 percent to 54 percent.) However, these modest changes don’t fully explain the dramatic drop in teen pregnancy.


So what really changed? Even though the same proportion of teens has used birth control during the past 20 years, the key to lower pregnancy rates has been a shift from condom use alone to more effective hormonal methods like the pill. It turns out that not all contraception is the same. No matter how well-educated they are, teens who do use birth control can’t reliably use condoms every time. To be sure, condoms prevent sexually transmitted diseases and are an important public health tool. But we now realize they should never, ever be the sole method of birth control for teens. They find condoms too much of hassle to use time after time—so they don’t.

Recognizing that condoms have a high risk of failure due to noncompliance, public health authorities and doctors encouraged more girls to get the pill. That quiet revolution has caused a major decline in unwanted pregnancies.

Still, despite the progress, 7 percent of all teenage girls get pregnant each year. In fact, half of all American pregnancies, regardless of a woman’s age, are unplanned, leading to more than a million abortions annually.

We’ve learned that some kinds of contraception are more prone to human error than others. But have we taken the lesson to heart? Half of the 3 million annual unintended pregnancies at any age in the United States occur among people using birth control. The pill is the most popular method, used by more than half of all women trying to avoid pregnancy. People believe it is highly reliable because it is over 99 percent effective when “used correctly” in supervised drug trials.