If the future health of their child doesn’t make them think twice about lighting up, a new study shows pregnant women may quit smoking if it means they get some cash.

A team of researchers from several universities the UK found 23 percent of women quit smoking during their pregnancy if they were offered a financial incentive to quit — in the form of a shopping voucher — compared to only nine percent of women who underwent traditional cessation programs. Twelve months later, follow-up tests showed 15 percent from the experimental group and four percent of the control group managed to stay smoke-free. The method’s modest success gave the team hope incentives may be an effective add-on to normal programs.

“Smoking in pregnancy remains a leading preventable cause of maternal and neonatal ill health and death in the United Kingdom and in most other developed countries,” the authors wrote. “This study provides substantial evidence of a promising and potentially cost-effective new intervention to add to present health service support.”

Smoking while pregnant is by and large one of the most harmful activities to a developing baby’s health. Women who smoke face greater rates of miscarriage, complications with the placenta (where the baby receives food and oxygen), early delivery, birth defects, and sudden infant death syndrome. Luckily, like smoking in general, the practice is falling to the wayside. According to the Centers for Disease Control and Prevention, 10 percent of women smoke within the last three months of pregnancy.

As part of their research, the team collected data on 612 pregnant smokers. They split the women into two groups, measuring each person’s individual level of cotinine, a biomarker frequently used to screen for recent exposure to tobacco smoke. One group received up to 400 pounds ($608) of vouchers if they signed up for specific smoking cessation programs and/or managed to quit smoking. The other group followed normal services that included a face-to-face appointment with a smoking cessation adviser, four support calls, and free nicotine replacement therapy for 10 weeks.

Ethics and Implications

The latest research offers a new, if unusual, way to get women to stop smoking. In their report, the researchers acknowledge there may be some ethical concerns with paying women not to engage in a behavior that is patently dangerous (and one they should just plain know better not to do). In their view, effectiveness must be weighed on a balance.

“In addition to effectiveness, an important outcome is cost-effectiveness, particularly the longer term cost per quality adjusted life year gained,” they wrote. “In the developed world there is now a clear socioeconomic gradient in smoking, with tobacco use concentrated among the poorest in society. Receipt of financial incentives can contribute to needed household income in advance of the arrival of a baby in low-income households.”

As evidenced by the 12-month drop off, quitting rates often have trouble staying consistent over the long term. Like weight loss and other major lifestyle changes, smoking cessation is seldom a switch to be flipped. Even if the bulk of the cravings have left, many people experience some residual urge to relapse.

“Only a few interventions, such as vaccines, are able to prevent disease,” they wrote. “If financial incentives are effective and cost-effective they may well have the future potential to sit with vaccines as an important preventive health care intervention strategy.”

Source: Tappin D, Bauld L, Purves D, et al. Financial incentives for smoking cessation in pregnancy: randomized controlled trial. BMJ. 2015.