PRAMS and Smoking

Background

Smoking during pregnancy remains one of the most common preventable causes of infant morbidity and mortality. Cigarette smoking before conception can cause reduced fertility and conception delay in women.¹ Maternal cigarette smoking during pregnancy increases the risk for pregnancy complications (e.g., placental previa, placental abruption, premature rupture of the membrane, preterm delivery, restricted fetal growth) and sudden infant death syndrome [SIDS].¹ Smoking around the time of conception has been associated with the development of cleft lip with or without cleft palate in infants.² Exposure to secondhand smoke after delivery increases an infant's risk for respiratory tract infections (e.g., bronchitis, pneumonia), ear infections, and death from SIDS.³ In 2002, 5%–8% of preterm deliveries, 13%–19% of term low-birth-weight deliveries, 23%–34% of SIDS, and 5%–7% of preterm-related deaths were attributable to prenatal smoking in the United States.⁴

Three Healthy People 2020 (HP 2020) national health objectives address smoking during pregnancy: 1) reducing the prevalence of women smoking prior to pregnancy to 14% (objective no. MICH-16.3), 2) reducing the prevalence of cigarette smoking among pregnant women to 1% (objective no. MICH-11.3), and 3) increasing the percentage of pregnant smokers who stop smoking during pregnancy to 30% (objective no. TU-6).⁵ This report can be used to highlight the importance of reducing smoking among women, including smoking during pregnancy.

States use the Pregnancy Risk Assessment Monitoring System (PRAMS) to survey women 2–6 months after delivery on a number of behaviors including smoking before, during, and after pregnancy. Core questions on smoking include—

• Have you smoked at least 100 cigarettes in the past 2 years?
• In the 3 months before you got pregnant, how many cigarettes did you smoke on an average day?
• In the last 3 months of your pregnancy, how many cigarettes did you smoke on an average day?
• How many cigarettes do you smoke on an average day now?

States also may add optional questions to their surveys, and these questions cover tobacco-related topics such as use of smokeless tobacco, receipt of prenatal care provider advice about quitting smoking, use of interventions to quit smoking, and smoking rules used in the home. 

PRAMS Methodology

PRAMS samples between 1,300 and 3,400 women who have had a recent live birth in each participating site annually. The sample is drawn from states’ birth certificate files using a standardized protocol. Sampling for PRAMS data collection takes place on a monthly basis and is continuous throughout the year. The PRAMS data collection methodology involves sending up to three mail surveys to sampled women and following up with nonresponders by telephone. PRAMS uses stratified sampling methods to allow each state to oversample high-risk populations—such as women who have low-birth-weight infants. Survey data are linked to selected birth certificate data and weighted for sample design, nonresponse, and noncoverage. Read the detailed methodology of PRAMS.

PRAMS Data on Smoking

Data from 2000 through 2008 in this report include sites achieving an overall weighted response of 70% for data through 2006 and a weighted response of 65% for data starting in 2007. Prevalence estimates and 95% confidence intervals (CIs) were calculated for smoking during the 3 months prior to pregnancy, smoking during the last 3 months of pregnancy, and smoking after delivery for each site and year during the study period. Estimates of the proportion of women who quit smoking during pregnancy and 95% CIs were calculated among women who reported smoking before pregnancy and reported no smoking during pregnancy for each site and year during the study period. Logistic regression was used to assess linear trends over time by site among those sites with at least 3 years of data. Proportion change was calculated using the first and last years of data available by site. Figure 1 to 4 display site-specific estimates by each indicator from the 29 sites that had 2008 data available. Prevalence estimates and 95% CIs for smoking during the last 3 months of pregnancy were calculated by age, race/ethnicity, education, and insurance status using combined data from the 29 sites that had 2008 data available (Table 5). Data were weighted to represent all live births delivered in each respective site in the given year. Analyses were conducted using SAS version 9.2 and SUDAAN version 10.0, to account for the complex survey design of PRAMS.

In 2008, the overall smoking prevalence during the 3 months prior to pregnancy was 23.0% from the 29 sites that had data available and ranged from 10.4% (Utah) to 39.4% (West Virginia) (Table 1 and Figure 1). In the 31 sites with at least 3 years of data during the study period, the prevalence of smoking before pregnancy significantly decreased over time in Minnesota, New Mexico, New York (excluding New York City), and Utah. The proportion change ranged from 12% (New Mexico) to 27% (Utah). In Louisiana, Mississippi, Ohio, Oklahoma, and West Virginia the prevalence of smoking before pregnancy significantly increased during the study period. The proportion change ranged from 6% (Oklahoma) to 33% (Louisiana). From the 29 sites that had data available in 2008, Utah (10.4%) was the only site to have already met the HP 2020 objective of reducing the prevalence of women smoking prior to pregnancy to 14%.

In 2008, the overall prevalence of smoking during the last 3 months of pregnancy was 12.8% from the 29 sites that had available data, and ranged from 5.1% (Utah) to 28.7% (West Virginia) (Table 2 and Figure 2). In the 31 sites with at least 3 years of data during the study period, the prevalence of smoking during the last 3 months of pregnancy significantly decreased over time in Illinois, Michigan, Minnesota, New Jersey, New York (excluding New York City), and Utah. The proportion change ranged from 20% (Michigan) to 30% (Utah and New York). In Louisiana and West Virginia, the prevalence of smoking during the last 3 months of pregnancy significantly increased over time during the study period, and the proportion change was 17% for West Virginia and 49% for Louisiana.

As for demographic groups, in 2008, the prevalence of smoking during the last 3 months of pregnancy was highest among women who were between 20–24 years of age (19.3%), were Alaska Native (30.4%), had less than 12 years of education (22.5%), or were Medicaid insured during prenatal care (22.1%) (Table 5).

In 2008, the overall prevalence of smoking after delivery was 17.6% from the 29 sites that had data available, and ranged from 7.1% (Utah) to 34.9%(West Virginia) (Table 3 and Figure 3). In the 31 sites with at least 3 years of data during the study period, the prevalence of smoking after delivery significantly decreased over time in Alaska, Colorado, Illinois, Minnesota, New Jersey, New Mexico, New York (excluding New York City), and Utah. The proportion change ranged from 11% (Alaska) to 28% (New York). In Louisiana, Mississippi, and West Virginia, the prevalence of smoking after delivery significantly increased over time during the study period, and the proportion change ranged from 10% (West Virginia) to 25% (Louisiana). 

In 2008, the proportion of smokers who quit smoking during pregnancy was 44.5% from the 29 sites that had data available, and ranged from 23.3% (Arkansas) to 57.1% (New Jersey) (Table 4 and Figure 4). In the 31 sites with at least 3 years of data during the study period, the proportion of smokers who quit smoking during pregnancy significantly increased over time in Illinois, Michigan, and New Jersey. The proportion change ranged from 19% (New Jersey) to 24% (Illinois and Michigan). In Louisiana and West Virginia, the proportion of women who quit smoking during pregnancy significantly decreased over time during the study period, and the proportion change was 16% in West Virginia to 17% in Louisiana. 

Use of PRAMS Data

PRAMS data can be used for developing, monitoring, and evaluating state tobacco control policies and programs to reduce smoking among female and pregnant smokers. States can prevent smoking initiation and reduce smoking before, during, and after pregnancy through sustained and comprehensive tobacco-control efforts (e.g., smoke-free policies, tobacco excise taxes, comprehensive coverage of cessation services). Health care providers should increase efforts to assess the smoking status of their patients and offer effective smoking cessation interventions to every female or pregnant smoker in their care.