Effects of voucher-based incentives on abstinence from cigarette smoking and fetal growth among pregnant women

Addiction. 2008 Jun;103(6):1009-18. doi: 10.1111/j.1360-0443.2008.02237.x.


Aims: This study examined whether voucher-based reinforcement therapy (VBRT) contingent upon smoking abstinence during pregnancy is an effective method for decreasing maternal smoking during pregnancy and improving fetal growth.

Design, setting and participants: A two-condition, parallel-groups, randomized controlled trial was conducted in a university-based research clinic. A total of 82 smokers entering prenatal care participated in the trial.

Intervention: Participants were assigned randomly to either contingent or non-contingent voucher conditions. Vouchers exchangeable for retail items were available during pregnancy and for 12 weeks postpartum. In the contingent condition, vouchers were earned for biochemically verified smoking abstinence; in the non-contingent condition, vouchers were earned independent of smoking status.

Measurements: Smoking outcomes were evaluated using urine-toxicology testing and self-report. Fetal growth outcomes were evaluated using serial ultrasound examinations performed during the third trimester.

Findings: Contingent vouchers significantly increased point-prevalence abstinence at the end-of-pregnancy (41% versus 10%) and at the 12-week postpartum assessment (24% versus 3%). Serial ultrasound examinations indicated significantly greater growth in terms of estimated fetal weight, femur length and abdominal circumference in the contingent compared to the non-contingent conditions.

Conclusions: These results provide further evidence that VBRT has a substantive contribution to make to efforts to decrease maternal smoking during pregnancy and provide new evidence of positive effects on fetal health.

Publication types

  • Randomized Controlled Trial
  • Research Support, N.I.H., Extramural

MeSH terms

  • Adult
  • Breath Tests / methods
  • Female
  • Fetal Development / drug effects
  • Health Promotion / methods*
  • Humans
  • Motivation*
  • Patient Compliance
  • Pregnancy*
  • Smoking / adverse effects
  • Smoking / psychology
  • Smoking Cessation / methods*
  • Smoking Cessation / psychology
  • Smoking Prevention*
  • Token Economy
  • Treatment Outcome