Objective. To determine the impact of a brief smoking intervention del
ivered by pediatricians in the context of usual well baby office visit
s on postnatal maternal smoking and relapse. Setting. Forty-nine priva
te pediatric practices including 128 practitioners. Design. Randomizat
ion of pediatric practices into minimal and extended intervention site
s with all enrolled mothers of newborns within a practice receiving th
e same level of intervention. Intervention. Smoking mothers in minimal
condition received a hospital packet containing written information a
bout passive smoking and a letter advising them to quit. Those in exte
nded condition received the hospital packet plus oral and written advi
ce at usual well baby visits: 2 weeks, 2, 4, and 6 months. Measurement
s. Smoking and relapse rates at 6 months postpartum, demographics asso
ciated with smoking status, attitudes, and knowledge in regard to pass
ive smoking, and recall surveys of mothers in regard to receiving advi
ce or written materials. Results. Two-thousand nine-hundred-one mother
s of newborns were enrolled in the study. Those in the extended condit
ion had higher quit rates (5.9% vs 2.7%, P < .01) and lower relapse ra
tes (45% vs 55%, P < .01) than those in the minimal condition. Mothers
' educational status and the presence of a smoking partner in the home
were the major demographic variables associated with smoking status a
t enrollment and at follow-up. Compared with smokers in the minimal co
ndition, those in extended at 6 months postpartum had significantly be
tter attitudes and knowledge regarding passive smoking and allowed les
s smoking in the home. Mothers attending extended practices reported m
uch higher rates of receiving oral advice and written materials than t
hose in the minimal condition. Conclusions. A brief-program can lead t
o major increases in the willingness of pediatricians to deliver smoki
ng advice. A 1- to 2-minute intervention delivered in the context of u
sual well baby care can have a positive impact on maternal smoking and
especially upon relapse prevention. A recent smoking history should b
e obtained from all mothers of newborns so that interventions can be a
imed at both cessation and relapse prevention.