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I f jjijrtransdermal nicotine patch use and hourly smoking in
pregnant women produced similar nicotine concentrations
-GA, Hardardottir H,
D K e t al E f f e c t s o f
>
nicotine or smoking on
centrations and materhemodynamics. Obstet
Objective
To determine die safety of transdermal
nicotine compared with continued
smoking in pregnant women who
. 'smoke..;
Design
Randomised, crossover trial with two
g~hour intervention periods.
Setting
University health centre in Connecticut, ;USA.
Participants
17 pregnant women who were > 18
years of age (mean age 28 y) and had
smoked 15 cigarettes per day for the
past year. Exclusion criteria were fetal
growth restriction, hypertension, use
of alcohol or illegal drugs during the
current pregnancy, positive results on
urine toxicology screening, use of
other tobacco products, salivary coti-
nine £ 85 ng/mL, fetal anomalies,
fetal arrhythmia, or placenta praevia.
15 women (88%) completed the study.
Intervention
Women were allocated to wear a 21mg nicotine patch (Hoechst-MarionRoussel, Kansas City, MO) for 8
hours or to smoke as they wished for
the same period. 1 week later, they
switched to the other intervention.
During the smoking phase, women
smoked outdoors to prevent women
wearing the patch from being exposed
to secondhand smoke. Women were
instructed to refrain from smoking after 8 p.m. the night before each intervention period.
plasma nicotine concentrations between patch use and smoking and
> 85% power to detect a change of 2
standard deviations in the middle cerebral artery RI. The area under the
plasma nicotine concentration-time
curve did not differ for patch use and
smoking (93 vs 89 ng-h/mL, P- 0.77),
nor did the area under the plasma
cotinine concentration-time curve differ for patch use and smoking (882 vs
964 ng-h/mL). Doppler measurements of the change in middle cerebral arteiy RI from baseline to peak
concentrations at 4 hours did not differ for patch use and smoking (0.002
vs -0.02, P= 0.3).
Conclusion
Area under the plasma concentrationtime curve for nicotine and cotinine
and change in the middle cerebral artery resistance index (RI)frombaseline
to 4 hours later.
Nicotine concentrations and middle
cerebral arteiy resistance indices were
similar in pregnant women after
8-hour use of a nicotine patch and after smoking approximately 1 cigarette
per hour for the same length of time.
Main results
Sources of funding: Hoecbst-Marion-Roussel
andNIH General Clinical Research Center.
Main outcome measures
The participants smoked a mean of 9
cigarettes during the smoking intervention period. The study had 80%
power to detect a 25% difference in
For article reprint: Dr. C.A, Oncken, Department of Medicine (MC 3940), University of
Connecticut Health Center, 263 Farmington
Avenue, Farmington, CT 06030, USA. FAX
860-679-1250.
creases the risk for low birthweight, preterm birth, antepartum haemorrhage, premature rupture of the membranes, and
perinatal death. However, even with the
use of effective strategies, relatively few
women quit, and few institutions implement effective programs in the course of
routine antenatal care.
Although this trial provided reassurance
about fetal cerebral blood flow, it also identified changes in fetal heart rate patterns
during nicotine use that would be widely
regarded as undesirable: a substantial increase in the baseline rate and a nonsignificant difference in loss of reactivity
(5/8 tracings after patch placement vs 1/6
tracings after smoking, P * 0.12). The odds
of loss of reactivity with the patch are 8.3
(95% CI 0.5 to > 450). Thus, the study
raises concerns about the possibility of fetal stress and about changes in fetal heart
rate and variability that risk being interpreted as evidence of fetal hypoxia, which
could lead to unnecessary interventions.
The study, however, is too small to address
the issue of safety. Larger trials with substantive fetal outcomes are needed before
I will begin introducing nicotine patches
into antenatal care.
Commentary
In the article by Oncken and colleagues, a
nicotine patch worn for 8 hours during
mid-to-late pregnancy gave women who
were heavy smokers blood levels of nicotine similar to those they obtained from
smoking as many cigarettes as they wished
m an 8-hour period. This finding shows
the potential for using nicotine to improve
smoking cessation during pregnancy. The
measure of relative fetal safety (middle cerebral artery blood flow) was reassuring.
Given the major problem, that at least a
quarter of pregnant women smoke, should
practitioners now offer nicotine replacement routinely to pregnant women who
are heavy smokers, as is recommended for
0
^er smokers (1)?
The need for a new approach is clear:
Cigarette smoking during pregnancy in-
Evidence-Based Medicine
May/June 1998
Judith Lumley, MBBS, PhD
La Trobe University
Melbourne, Victoria, Australia
Reference
1. Silagy C, Mant D, Fowler G, Lancaster
T, Nicotine replacement therapy for smoking cessation. In: The Cochrane Database of
Systematic Reviews. The Cochrane Library.
Oxford: Update Software; 1997, Issue 4.
Etiology
91
Downloaded from http://ebm.bmj.com/ on June 17, 2017 - Published by group.bmj.com
8-hour transdermal nicotine patch use and
hourly smoking in pregnant women produced
similar nicotine concentrations
Evid Based Med 1998 3: 91
doi: 10.1136/ebm.1998.3.91
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