Proponents of abstinence education played down concerns about unintended pregnancies.
"Pregnancy is not a disease. . . . The women making these choices are making a conscious choice. They are not stupid," said Leslee J. Unruh, president of the Abstinence Clearinghouse. "Women don't want to use birth control because of the side effects. And a lot of men refuse to use a condom."
Family planning is a "fiscally conservative policy," countered Jensen of the Women's Health Research Unit. For every $1 spent on contraceptive services, he said, $3 is saved in other government programs such as Medicaid, the State Children's Health Insurance Program, welfare and education.
Several recent studies found that as the abstinence-until-marriage movement surged, there was a "considerable drop" in comprehensive sex education from 1988 to 2000, Santelli said. "Women in their twenties have probably gotten less effective information about contraception," he said.
Blumenthal has encountered women who mistakenly believe they are infertile because of age or confusion about a missed period.
In some cases, women and recent generations of physicians have been scared off from certain types of birth control or simply not trained in products that disappeared from the market. Of the women using birth control in 1995, 7 percent reported using an intrauterine device, or IUD. That figure fell to 2 percent in 2002, a drop Trussell attributed to "the legacy" of the Dalkon Shield IUD, which was pulled off the market in 1974 after causing infections that killed at least 18 women.
A growing number of women -- and especially teenagers -- are using condoms with another form of contraception, a finding that suggests they are concerned about preventing pregnancy and sexually transmitted diseases.
"It's clear that contraception is a service people use and want to use, judging by the almost universal use in America," Blumenthal said. "We're offering a service people find useful."