Research suggests that poor women lack access to reliable birth control.
(Andrew Harrer/Bloomberg)

Poor women are five times as likely as affluent women to have an unintended birth, new research from the Brookings Institution shows — and that drives inequality.

The difference boils down to contraceptive use, not sexual activity. There is no “sex gap” by income, researchers emphasized. Promiscuity doesn’t vary along class lines. Access to the most reliable forms of birth control, however, does.

The Brookings study examined fertility outcomes of 3,885 single women, none of whom were trying to get pregnant. Those with incomes below the poverty line were twice as likely to have sex without protection as those with incomes four times the poverty line, data from the National Survey of Family Growth showed.

The failure rate for progestin-releasing  IUDs, for example, which can cost up to $1,000, is .08 percent, according to the CDC. The failure rate for condoms: 12 percent.

“In a sense, inequality starts before birth,” said co-author Richard Reeves, policy director of the Center on Children and Families. “An important part of the policy story is helping parents have children when they're ready. The life chances of those children will be better as a result.”

The average American woman is sexually active for 10 years before getting married, Reeves noted. Preaching abstinence is not a realistic approach to reducing unplanned pregnancies.

Brookings Institution


Nine percent of women with incomes at or below the poverty line reported having a pregnancy in the past year, the NSFG data showed, compared to only 3 percent of women in the top income bracket.


The economic argument for more widely available birth control: Unintended pregnancies cost taxpayers $21 billion each year, according to an analysis released by the Guttmacher Institute,  a nonprofit reproductive health organization. That averages out to a cost of about $366 per every woman of childbearing age in the U.S., Wonkblog’s Chris Ingraham reported.

Previous research suggests “women with limited economic prospects will control their fertility less carefully because they have less to lose,” the Brookings authors noted. To test this theory, they surveyed women across income levels about their attitudes on unexpected pregnancies and found no significant difference.

A growing body of evidence indicates that limited access to sex education and contraceptives in poor communities widens the income-fertility gap. Equalizing birth control use could reduce the ratio of unintended births by half, Reeves estimated.

“The passage of the Affordable Care Act represents a huge advance here, by making better contraception more financially accessible,” the study said,  “but lack of knowledge about the efficacy of IUDs and implants and access to quality medical advice about contraception are still significant problems.”

Courtesy of the Brookings Institution

Wealthier women who face unplanned pregnancies were also far more likely to have abortions. Thirty-two percent of those surveyed in the highest income bracket had an abortion in the past year, compared to 9 percent of poor pregnant women.

Researchers reported a financial barrier to safe procedures is the primary deterrent. Equalizing abortion rates, they calculate, could reduce the unintended birth ratio by a third.

Courtesy of the Brookings Institution