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


METHODS
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.


METHODS
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.


METHODS
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.


RESULTS
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.
Heil
Sarah H
SH
Departments of Psychiatry, University of Vermont, Burlington, VT 05401, USA. sarah.heil@uvm.edu
Higgins
Stephen T
ST
Bernstein
Ira M
IM
Solomon
Laura J
LJ
Rogers
Randall E
RE
Thomas
Colleen S
CS
Badger
Gary J
GJ
Lynch
Mary Ellen
ME
D000328:Adult; D001944:Breath Tests / Q000379:methods; D005260:Female; D047109:Fetal Development / Q000187:drug effects; D006293:Health Promotion / Q000379:methods*; D006801:Humans; D009042:Motivation; D010349:Patient Compliance; D011247:Pregnancy; D012907:Smoking / Q000009:adverse effects / Q000523:psychology; D016540:Smoking Cessation / Q000379:methods* / Q000523:psychology; D000074606:Smoking Prevention; D014040:Token Economy; D016896:Treatment Outcome