Not-So-Accidental Pregnancies

To hang onto the right guy, some women may go as far as getting pregnant.

Of the millions of pregnancies reported annually in the United States, about half are considered unintended or unplanned. At the same time, nine in ten women report using birth control—the most popular of which is more than 90 percent effective.

Melinda Spohn, a social worker and researcher at Spokane Falls Community College in Washington, decided to study why so many of her clients told her that their pregnancies were unplanned, despite the variety of easily available birth control.

Some of the women admitted that they had not used birth control with guys who had appealing characteristics. To determine whether such behavior is widespread, Spohn surveyed nearly 400 women at two community colleges. More than a third of women said they had risked pregnancy in the past with men who had attractive qualities—such as commitment to the relationship, good financial prospects or the desire for a family—but hadn't discussed the possibility of pregnancy with their partner. It was unclear how many women actually became pregnant.

The idea of pervasive "gotcha" pregnancies has skeptics. Andrea Gerber, a health educator in Seattle, believes few women seek out single motherhood or believe a man will stick around if she becomes pregnant.

It's more likely, she says, that couples aren't educated about proper birth control use. Indeed, a study in the American Journal of Health Behavior found that 24 percent of low-income, sexually active adults routinely use condoms incorrectly, leading to a high rate of pregnancy and disease.

Spohn contends that women have a built-in biological desire to reproduce with men who are good providers. She presented her pregnancy survey at the Human Behavior and Evolution Society's annual meeting. Her advice to men: "Beware!"