More than 45 million people smoke, about 19 percent of all adults in the U.S., according to the Centers for Disease Control and Prevention.

Public health campaigns have tried to reduce that number through dire warnings and scary ads. And many cities and states have made cigarettes less appealing — at least financially — by adding on hefty taxes.

But in Eugene, Ore., they’re trying something new — something they think hasn’t been done anywhere else. Beginning this July, they’re paying pregnant women to quit smoking.

Kristian Foden-Vencil, who has covered this story for Oregon Public Broadcasting, said the idea was born out of research that shows kids can sometimes do better in school when they're paid for their grades. Under the new program, women who go to a doctor in Eugene and are pregnant and smokers are invited to the program.

When the woman comes back for a 16-week checkup, if she passes a urine test for nicotine, she's given a $20 gift certificate, Foden-Vencil said. At 36 weeks, he said, if she passes another test she'll get a $30 gift certificate. There's a $50 gift certificate as well, plus a final, $100 gift certificate if the woman remains a non-smoker six weeks after her child is born.

"That's $200, all told, and it's a gift certificate, so she can go down to a big grocery store and select whatever she wants, except tobacco, obviously, firearms and alcohol," he said.

According to research, 40 percent of women of childbearing age on Oregon's health plan smoke cigarettes, and 32 percent continued to smoke while pregnant — resulting in up to five percent of fetal deaths and 10 percent of pre-term deliveries.

So there's an economic incentive not just for the mothers, but also for the health plan as well.

Oregon has $2 billion from the federal government to try out new ideas for improving health, Foden-Vencil said. The health plan turned to its patients, and to doctors, who said it all comes down to incentives.

"If you want to give us money, (the doctors said), then maybe we can get people to give up smoking," he explained.

Patients aren't sanguine about this being easy — coupling the stress of quitting smoking with the stress of pregnancy. But early signs are that women will at least be willing to consider it.