UC San Diego

Introduction

Pregnant smokers are advised to quit; however, many struggle to do so. Behavioral counseling can increase quitting success, but the efficacy of telephone counseling for pregnant smokers has not been established. This study tests the efficacy of pregnancy-specific counseling, embedded in the ongoing operations of a state quitline.

Design

In this two-group RCT, participants were randomly assigned to the intervention (telephone counseling plus self-help materials, n=584) or the control group (self-help materials only, n=589).

Setting/participants

Participants were pregnant smokers (N=1,173) in the first 27 weeks of gestation who called a state quitline between September 2000 and May 2003 for help with quitting.

Intervention

The primary component of the intervention was telephone counseling using a semi-structured protocol developed specifically for pregnant smokers. It drew its basic structure and clinical content from a previously tested counseling protocol for adult quitline callers, while including pregnancy-specific content and additional counseling sessions (nine rather than the standard five).

Main outcome measures

Subjects were evaluated on prolonged abstinence at the third trimester (about 29 weeks' gestation) and at 2 and 6 months postpartum. Data were analyzed in 2015.

Results

Abstinence was higher for the intervention than the control group at the end of pregnancy (30-day abstinence, 29.6% vs 20.1%; p<0.001); 2 months postpartum (90-day abstinence, 22.1% vs 14.8%; p<0.001); and 6 months postpartum (180-day abstinence, 14.4% vs 8.2%; p<0.001). Cotinine-corrected (≤13 ng/mL) 7-day abstinence rates at the end of pregnancy supported the intervention effect (35.8% vs 22.5%, p<0.001).

Conclusions

A pregnancy-specific counseling protocol, embedded in a state quitline, was effective in helping pregnant smokers quit and stay quit postpartum. Wide adoption of this intervention could help reduce the rate of maternal smoking and prevent its devastating health consequences.

Trial registration

This study is registered at www.clinicaltrials.gov NCT02144883.