1 figure, 2 tables omitted
Cigarette smoking during pregnancy adversely affects the health of both
mother and child. The risk for adverse maternal conditions (e.g., premature
rupture of membranes, abruptio placentae, and placenta previa) and poor pregnancy
outcomes (e.g., neonatal mortality and stillbirth, preterm delivery, and sudden
infant death syndrome) is increased by maternal smoking.1- 3 Infants
born to mothers who smoke weigh less than other infants, and low birthweight
(<2,500 grams) is a key predictor for infant mortality.1,2,4 Infertility
and conception delay also might be elevated by smoking.1 National
health objectives for 2010 target an increase in cessation to 30% among pregnant
smokers during the first trimester (objective 27-6) and abstinence from cigarettes
by 99% of women giving birth (objective 16-17).5 To
assess progress toward these goals, CDC analyzed state-specific trends in
maternal smoking during 1990-2002 by using data collected on birth certificates.
This report summarizes the results of those analyses, which indicated that
whereas participating areas observed a significant decline in maternal smoking
during the surveillance period, 10 states reported recent increases in smoking
by pregnant teens. Although the widespread public health message to abstain
from smoking during pregnancy has helped decrease maternal smoking, to reduce
prevalence further, implementation of additional interventions are required.
Data for the analyses were collected on birth certificates and reported
by 49 reporting states, the District of Columbia (DC), and New York City (NYC)
to CDC’s National Vital Statistics System, operated by the National
Center for Health Statistics. Data on maternal smoking in California were
not included because the state’s birth certificate does not collect
this information in the standard format. Not all states had data available
for the entire observation period (1990-2002). To obtain statistically reliable
prevalences for smoking during pregnancy among teen mothers by state, 2 years
of data were averaged and compared for three periods (i.e., 1990-1991, 1995-1996,
and 2001-2002). All differences are statistically significant (p<0.05)
unless otherwise noted.
In 2002, smoking during pregnancy was reported by 11.4% of all women
giving birth in the United States, a decrease of 38% from 1990, when 18.4%
reported smoking3. From 1990 to 2002, all 44
states (and DC) with comparable data for the entire observation period reported
significant declines in maternal smoking. However, the declines were variable,
ranging from 5.8% in West Virginia (from 27.8% in 1990 to 26.2% in 2002) to
68.0% in Massachusetts (from 25.3% in 1990 to 8.1% in 2002).
Since 1990, maternal smoking for females aged 15-19 years has fluctuated.
Every year from 1996 through 2001, these mothers had the highest percentage
of smoking during pregnancy than any other age group.3,6 However,
in 2002, the percentage of maternal smokers aged 15-19 years (16.7%) was the same as that for women aged 20-24 years, with
the highest percentage observed among women aged 18-19 years (18.2%).
Of 45 states (and DC) where maternal smoking percentages were calculated
for teen mothers during both 1990-1991 and 1995-1996, a total of 34 states
had significant declines. Of the 45 reporting states, DC, and NYC, where maternal
smoking percentages could be calculated for teen mothers for both 1995-1996
and 2001-2002, a total of 16 states and NYC had significant declines, but
15 states had significant increases for teen maternal smoking. Of these 15
states, 10 had a complete trend reversal from a significant decrease from
1990-1991 to 1995-1996 to a significant increase from 1995-1996 to 2001-2002.
Thirteen states had consistent and significant declines among pregnant
women aged 15-19 years, both from 1990-1991 to 1995-1996 and from 1995-1996
to 2001-2002; four states had significantly higher teen smoking percentages
in 2001-2002, compared with 1990-1991.
TJ Mathews, MS, Div of Vital Statistics, National Center for Health
Statistics; CC Rivera, Div of Reproductive Health, National Center for Chronic
Disease Prevention and Health Promotion, CDC.
Smoking during pregnancy has declined in the United States, in response
to public education and public health campaigns.1 Neonatal
health-care costs attributable to maternal smoking in the United States have
been estimated at $366 million per year.4 Smoking-cessation
programs remain a crucial strategy for preventing poor birth outcomes and
decreasing the social and financial costs of smoking during pregnancy.
The findings in this report are subject to at least two limitations.
First, no data are presented from California, where 13.2% of U.S. births occurred
in 2002, but smoking is not reported on birth certificates in the standard
format. However, California annually samples mothers aged ≥15 years through
its Maternal and Infant Health Assessment program. Data are stratified by
age, region, maternal education, and ethnicity and weighted so that results
can be generalized statewide. In 1999, maternal smoking prevalence was 11.5%,
lower than the 12.6% reported for the United States; among teen mothers in
California aged 15-19 years, smoking prevalence was 16.7%,7 compared
with 18.1% for the United States. Second, prenatal smoking is underreported
on birth certificates.1 Underreporting might
be related to the wording of the smoking question, the timing of the data
collection (e.g., during prenatal care versus after the live birth), and the
stigma associated with smoking during pregnancy, particularly in cases of
poor birth outcome. However, despite underreporting, the trends and variations
in smoking derived from birth certificate data have been confirmed with data
from other sources (e.g., National Survey of Family Growth and Pregnancy Risk
Assessment Monitoring System).8
Changes in the smoking question on the birth certificate can help clarify
smoking behavior during pregnancy. On the basis of a study of alternative
smoking questions in California,9 the question
on maternal smoking has been redesigned for the revised U.S. standard certificate
of live birth. The new question on smoking during pregnancy asks whether the
mother smoked during the 3 months before pregnancy and during each trimester
of pregnancy, clarifying the time of initiation and duration of smoking and
providing data on women who quit smoking early in pregnancy.
Vermont implemented a revised smoking question on its birth certificate
in 2000, and data for 2001-2002 indicated higher percentages because of more
complete identification of smoking during pregnancy.10 The
impact from this change on national data was negligible because Vermont accounts
for less than 0.2% of all U.S. births. All states are expected to revise their
smoking questions, resulting in discontinuity of data such as those in this
report, but improving accuracy of reporting.
Women who quit smoking before or during pregnancy can substantially
reduce or eliminate risks to themselves and their infants.1 The
National Partnership to Help Pregnant Smokers Quit includes CDC and approximately
60 other organizations, working to ensure that health-care providers assess
smoking status before, during, and after pregnancy and provide best-practice
counseling on smoking cessation. Evidence suggests that specific cessation
programs have been at least partly successful.6 However,
not all women have responded to this public health message1;
further efforts are needed to persuade these women of the health risks posed
to their infants and themselves from smoking during pregnancy.
Smoking During Pregnancy—United States, 1990-2002. JAMA. 2004;292(18):2206-2208. doi:10.1001/jama.292.18.2206-b