Maternal smoking during pregnancy (MSDP) increases the risk of adverse pregnancy and birth outcomes and may have long-lasting effects in the offspring.Financial incentives may increase smoking abstinence rate in pregnancy and therefore reduce MSDP related negative health effects. This is a randomized open label study comparing financial incentives for smoking abstinence with no financial incentives for smoking abstinence.Research objectives

1. To test the efficacy of financial incentives on smoking abstinence rate among pregnant smokers;
2. To explore the heterogeneity of efficacy according to individual characteristics: socioeconomic status, social background, smoking characteristics, personality traits, time and risk preferences to determine profiles of women which could benefit best from this kind of intervention;
3. To provide a cost-benefit analysis based on the cost of newborn and children disease due to maternal smoking during pregnancy.

Multicenter, national study. Participants are pregnant smokers of at least 18 years old, smoking at least 5 manufactured or 3 rolled-on-their-own cigarettes per day. They will be randomly assigned according to a 1:1 ratio to receive either a financial incentive (20€/visit) to attend the 5 study visits (control group) or receive this show-up incentive plus an incentive for being abstinent at visit(s) on a progressive manner (treatment group). The incentives will be delivered as vouchers. Two hundred and forty pregnant smokers will be randomized into the control and treatment groups, respectively. The study will be run in several maternity wards across France all of whom routinely treat pregnant smokers.

Expected results

• Financial incentives rewarding progressive abstinence from smoking will increase abstinence rate more than lack of financial incentives.
• Forward looking and time consistent women will be more likely to stop smoking.
• If the clinical efficacy and cost effectiveness are demonstrated, financial incentives can be introduced as a standard intervention in helping pregnant smokers quit.

Inclusion Criteria:

1. Pregnant women
2. At least 18 years old
3. Smoking at least 5 manufactured cigarettes or 3 rolled-on-your-own cigarettes
4. Of <18 weeks of gestation
5. Motivated to quit smoking
6. Affiliated to social security system
7. And who signed the written informed consent form

Exclusion Criteria:

1. Psychiatric disorders
2. Use of other tobacco products (pipe, cigar, oral tobacco) than cigarettes
3. Use of bupropion or varenicline
4. Use of electronic cigarettes during the current pregnancy
5. Women already included in a biomedical research