By Ceci Connolly
Washington Post Staff Writer
Tuesday, January 4, 2005; Page A01

At a time when the medical community has been heartened by a decline in risky sexual behavior by teenagers, a different problem has crept up: More adult women are forgoing birth control, a trend that has experts puzzled -- and alarmed about a potential rise in unintended pregnancies.

Buried in the government's latest in-depth analysis of contraceptive use was the finding that the number of women who had sex in the previous three months but did not use birth control rose from 5.2 percent in 1995 to 7.4 percent in 2002. That means that as many as 11 percent of all women are at risk of unintended pregnancy at some point during their childbearing years (ages 15 to 44).

Researchers at the National Center for Health Statistics took pains to point out that the "increase is statistically significant" and that the "apparent change merits further study." Other analysts called the spike a troubling development that translates into at least 4.6 million sexually active women at risk of conceiving a child they had not planned on.

Because the survey is so large (more than 7,600 women) and known for its accuracy, "an increase of even two percentage points is worrisome," said John S. Santelli, a professor of population and family health at the Mailman School of Public Health at Columbia University. Even as he cheered the news that a growing number of teenagers are using contraception, Santelli wondered whether doctors are neglecting women.

"Maybe we're failing with women over 21," Santelli said.

Although unintended pregnancies can be welcome surprises, the danger from a public health and societal standpoint is that many of the women are financially or psychologically unprepared for parenthood at that point in their lives.

The number of unintended pregnancies "is a very difficult concept to measure accurately," said James Trussell, director of the Office of Population Research at Princeton University and an authority on contraceptive trends.

In analyzing previous reports by the National Center for Health Statistics, Trussell has determined that half of all unintended pregnancies occur among the more than 95 percent of women who used some type of contraception, probably because the method failed or was used improperly. That means the other half of unintended pregnancies came from the sliver of the population not using birth control.

"That is why this is of enormous concern," he said in an interview. "This tiny minority contributes half of all unintended pregnancies."

The data come from one-on-one interviews with 12,500 women and men ages 15 to 44. Government interviewers, who spent an average of 85 minutes with each person, found that 98 percent of women reported using contraception during their reproductive years, and the pill was the most popular choice, followed by female sterilization -- usually by having their fallopian tubes tied. Female respondents were also asked about their partners' use of birth control methods, such as condoms.

The December report did not tabulate unintended pregnancies, though preliminary information from the Centers for Disease Control and Prevention found a slight increase in the birth rate in 2003, most notably in women older than 30.

Physicians, statisticians and advocates who specialize in reproductive health had several theories for the rise in unprotected sex. They pointed to possible factors such as gaps in sex education, the cost of birth control, declining insurance coverage, fears of possible side effects of contraceptives and personal attitudes about childbearing.

It is possible, said Paul Blumenthal, that many more women are trying to conceive and thus have stopped using contraception. But the Johns Hopkins University professor said it is more likely that more women have found the cost of birth control burdensome.

"Because the number of uninsured has increased, these women might be on the short end of that stick," he said. Since 2001, the number of uninsured Americans has risen by 4 million.

Jeffrey Jensen, director of the Women's Health Research Unit at Oregon Health and Science University, said he regularly encounters patients who have trouble affording birth control, even if their private insurance covers it.

"It is absolutely unconscionable that women have a co-pay of $20 or $25 [a month] for contraceptives and men are getting off scot-free," Jensen said. Drug companies "have cut way back" on free samples and many women turn to less effective types of birth control because of cost, he said, "running a greater risk of pregnancy as a result."

Of the 34 million women in need of contraceptive services -- those who are not sterilized, pregnant or trying to conceive -- about 17 million qualified for publicly funded care, according to a 2002 report by the nonprofit Alan Guttmacher Institute. Of that number, 6.7 million received government-funded services, most through Medicaid or the Title X family-planning program.

But Title X "is nowhere near keeping up with inflation," said Susanne Martinez, vice president of public policy at the Planned Parenthood Federation of America. Adjusted for inflation, the program's 2003 budget was 57 percent smaller than it was in 1980, she said. In addition, Title X dollars are now spent on a broader range of services, such as testing for sexually transmitted diseases.

Many physicians put partial blame on federally funded abstinence-only education programs that by law prohibit discussion of contraceptives, except to detail their failure rates.

"We are spending an enormous amount of money on something that hasn't been shown to work," Trussell said. "It's a giant step backwards."

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."