The survey included thousands of white, African-American, and Hispanic teen girls, living in 19 states, who gave birth between 2004 and 2008.
Among the findings:
Nearly a fourth (23.6%) of the teens who did not use birth control said it was because their partners did not want to.
Twenty-two percent said even though they did not set out to have a baby, they would not mind if they got pregnant.
Teens in five states were asked about their use of specific contraceptives. About 24% used condoms, about 20% used oral contraceptives, and about 5% used highly unreliable methods such as rhythm and early withdrawal.
Hispanic teens were the most likely to mistakenly believe that they could not get pregnant at the time their babies were conceived, with 42% reporting this, compared to 32% of African-Americans and 27% of whites.
About 1 in 4 white and Hispanic teen moms and 1 in 5 black teen moms said they did not use birth control because their partners did not want to.
Teen Birth Rate Declining, But Still High
While fewer teens overall are having babies in the United States, the teen birth rate is still among the highest of any developed country. In 2009, close to 400,000 teens in the U.S. gave birth, the CDC says.
Teen mothers are more likely than other teenage girls to drop out of school and live below the poverty line, and their daughters are more likely to become teen mothers themselves.
It was not clear why the 31% of teen moms who did not use birth control mistakenly thought they could not get pregnant or why 22% said they did not really mind getting pregnant, even though it was not their intent.
“This was beyond the scope of the study, but it is an indication of ambivalence about this issue, which is a big problem in general,” Gavin says, adding that sex education efforts should stress motivating young girls to want to avoid pregnancy.
Lawrence Finer, PhD, of the reproductive health research and policy organization Guttmacher Institute, says it is clear from the survey that misperceptions about fertility are common.
“The risk of becoming pregnant with any one act of unprotected sex is small, so it may be that teen girls who have sex a few times and don’t become pregnant come to believe that they can’t become pregnant,” he says.
Finer says there has been a decline in the number of programs providing comprehensive education about sexuality in recent years.
“We are not providing teens with access to education and the broadest range of contraceptive options,” he says.