Van T. Tong

Infant Morbidity and Mortality Attributable to Prenatal Smoking in the U.S.

BACKGROUND Although prenatal smoking continues to decline, it remains one of the most prevalent preventable causes of infant morbidity and mortality in the U.S. PURPOSE The aim of this study was to estimate the proportion of preterm deliveries, term low birth weight deliveries, and infant deaths attributable to prenatal smoking. METHODS Associations were estimated for prenatal smoking and preterm deliveries, term low birth weight (<2500 g) deliveries, sudden infant death syndrome (SIDS), and preterm-related deaths among 3,352,756 singleton, live births using the U.S. Linked Birth/Infant Death Data Set, 2002 birth cohort. The 2002 data set is the most recent, in which 49 states used the same standardized smoking-related question on the birth certificate. Logistic regression models estimated ORs of prenatal smoking for each outcome, and the prenatal smoking population attributable fraction was calculated for each outcome. RESULTS Prenatal smoking (11.5% of all births) was significantly associated with very (AOR=1.5, 95% CI=1.4, 1.6); moderate (AOR=1.4, 95% CI=1.4, 1.4); and late (AOR=1.2, 95% CI=1.2, 1.3) preterm deliveries; term low birth weight deliveries (AOR=2.3, 95% CI=2.3, 2.5); SIDS (AOR=2.7, 95% CI=2.4, 3.0); and preterm-related deaths (AOR=1.5, 95% CI=1.4, 1.6). It was estimated that 5.3%-7.7% of preterm deliveries, 13.1%-19.0% of term low birth weight deliveries, 23.2%-33.6% of SIDS, and 5.0%-7.3% of preterm-related deaths were attributable to prenatal smoking. Assuming prenatal smoking rates continued to decline after 2002, these PAFs would be slightly lower for 2009 (4.4%-6.3% for preterm-related deaths, 20.2%-29.3% for SIDS deaths). CONCLUSIONS Despite recent declines in the prenatal smoking prevalence, prenatal smoking continues to cause a substantial number of infant deaths in the U.S.

Estimates of Nondisclosure of Cigarette Smoking Among Pregnant and Nonpregnant Women of Reproductive Age in the United States

Although clinic-based studies have used biochemical validation to estimate the percentage of pregnant women who deny smoking but are actually smokers, a population-based estimate of nondisclosure of smoking status in US pregnant women has not been calculated. The authors analyzed data from the 1999-2006 National Health and Nutrition Examination Survey and estimated the percentage of 994 pregnant and 3,203 nonpregnant women 20-44 years of age who did not report smoking but had serum cotinine levels that exceeded the defined cut point for active smoking (nondisclosure). Active smoking was defined as self-reporting smoking or having a serum cotinine concentration that exceeded the cut point for active smoking. Overall, 13.0% (95% confidence interval (CI): 8.8, 17.1) of pregnant women and 29.7% (95% CI: 27.3, 32.1) of nonpregnant women were active smokers. Nondisclosure was higher among pregnant active smokers (22.9%, 95% CI: 11.8, 34.6) than among nonpregnant smokers (9.2%, 95% CI: 7.1, 11.2). Among pregnant active smokers, nondisclosure was associated with younger age (20-24 years). Among nonpregnant active smokers, nondisclosure was associated with Mexican-American and non-Hispanic black race/ethnicity. Studies and surveillance systems that rely on self-reported smoking status are subject to underestimation of smoking prevalence, especially among pregnant women, and underreporting may vary by demographic characteristics.

Maternal Mortality and Morbidity in the United States: Where Are We Now?

This article provides a brief overview of the work conducted by the Division of Reproductive Health at the Centers for Disease Control and Prevention on severe maternal morbidity and mortality in the United States. The article presents the latest data and trends in maternal mortality and severe maternal morbidity, as well as on maternal substance abuse and mental health disorders during pregnancy, two relatively recent topics of interest in the Division, and includes future directions of work in all these areas.

Zika Virus Disease in Colombia — Preliminary Report

Background Colombia began official surveillance for Zika virus disease (ZVD) in August 2015. In October 2015, an outbreak of ZVD was declared after laboratory-confirmed disease was identified in nine patients. Methods Using the national population-based surveillance system, we assessed patients with clinical symptoms of ZVD from August 9, 2015, to April 2, 2016. Laboratory test results and pregnancy outcomes were evaluated for a subgroup of pregnant women. Concurrently, we investigated reports of microcephaly for evidence of congenital ZVD. Results By April 2, 2016, there were 65,726 cases of ZVD reported in Colombia, of which 2485 (4%) were confirmed by means of reverse-transcriptase-polymerase-chain-reaction (RT-PCR) assay. The overall reported incidence of ZVD among female patients was twice that in male patients. A total of 11,944 pregnant women with ZVD were reported in Colombia, with 1484 (12%) of these cases confirmed on RT-PCR assay. In a subgroup of 1850 pregnant women, more than 90% of women who were reportedly infected during the third trimester had given birth, and no infants with apparent abnormalities, including microcephaly, have been identified. A majority of the women who contracted ZVD in the first or second trimester were still pregnant at the time of this report. Among the cases of microcephaly investigated from January 2016 through April 2016, four patients had laboratory evidence of congenital ZVD; all were born to asymptomatic mothers who were not included in the ZVD surveillance system. Conclusions Preliminary surveillance data in Colombia suggest that maternal infection with the Zika virus during the third trimester of pregnancy is not linked to structural abnormalities in the fetus. However, the monitoring of the effect of ZVD on pregnant women in Colombia is ongoing. (Funded by Colombian Instituto Nacional de Salud and the Centers for Disease Control and Prevention.).

Nicotine and the Developing Human A Neglected Element in the Electronic Cigarette Debate

The elimination of cigarettes and other combusted tobacco products in the U.S. would prevent tens of millions of tobacco-related deaths. It has been suggested that the introduction of less harmful nicotine delivery devices, such as electronic cigarettes or other electronic nicotine delivery systems, will accelerate progress toward ending combustible cigarette use. However, careful consideration of the potential adverse health effects from nicotine itself is often absent from public health debates. Human and animal data support that nicotine exposure during periods of developmental vulnerability (fetal through adolescent stages) has multiple adverse health consequences, including impaired fetal brain and lung development, and altered development of cerebral cortex and hippocampus in adolescents. Measures to protect the health of pregnant women and children are needed and could include (1) strong prohibitions on marketing that increase youth uptake; (2) youth access laws similar to those in effect for other tobacco products; (3) appropriate health warnings for vulnerable populations; (4) packaging to prevent accidental poisonings; (5) protection of non-users from exposure to secondhand electronic cigarette aerosol; (6) pricing that helps minimize youth initiation and use; (7) regulations to reduce product addiction potential and appeal for youth; and (8) the age of legal sale.

Prenatal Smoking Prevalence Ascertained from Two Population-Based Data Sources: Birth Certificates and PRAMS Questionnaires, 2004

Objectives. This study provided a population-based estimate of the prevalence of smoking during pregnancy by combining information from two data sources: birth certificates (BCs) and a self-administered questionnaire. Methods. We analyzed data from 39,345 women who delivered live births in one of 24 states and responded to a questionnaire from the Pregnancy Risk Assessment Monitoring System (PRAMS), an ongoing, state- and population-based surveillance system. We compared prevalence of smoking during pregnancy based on the BC, the PRAMS questionnaire, and the two data sources combined. Data were weighted to represent all women delivering live births in each of the 24 states during 2004. Results. The combined estimate indicated that 15.1% of women reported smoking during pregnancy, whereas the BCs alone reported 10.4% and the PRAMS questionnaires alone reported 13.4%. Conclusions. Based on the combined BC and PRAMS questionnaire data, the number of infants exposed to tobacco in-utero may be 31% higher than is currently reported on the BCs. Combining the data from the two different sources led to higher ascertainment of prenatal smoking.

Prevalence and patterns of marijuana use among pregnant and nonpregnant women of reproductive age.

OBJECTIVE The objective of the study was to provide national prevalence, patterns, and correlates of marijuana use in the past month and past 2-12 months among women of reproductive age by pregnancy status. STUDY DESIGN Data from 2007-2012 National Surveys on Drug Use and Health, a cross-sectional nationally representative survey, identified pregnant (n = 4971) and nonpregnant (n = 88,402) women 18-44 years of age. Women self-reported marijuana use in the past month and past 2-12 months (use in the past year but not in the past month). χ(2) statistics and adjusted prevalence ratios were estimated using a weighting variable to account for the complex survey design and probability of sampling. RESULTS Among pregnant women and nonpregnant women, respectively, 3.9% (95% confidence interval [CI], 3.2-4.7) and 7.6% (95% CI, 7.3-7.9) used marijuana in the past month and 7.0% (95% CI, 6.0-8.2) and 6.4% (95% CI, 6.2-6.6) used in the past 2-12 months. Among past-year marijuana users (n = 17,934), use almost daily was reported by 16.2% of pregnant and 12.8% of nonpregnant women; and 18.1% of pregnant and 11.4% of nonpregnant women met criteria for abuse and/or dependence. Approximately 70% of both pregnant and nonpregnant women believe there is slight or no risk of harm from using marijuana once or twice a week. Smokers of tobacco, alcohol users, and other illicit drug users were 2-3 times more likely to use marijuana in the past year than respective nonusers, adjusting for sociodemographic characteristics. CONCLUSION More than 1 in 10 pregnant and nonpregnant women reported using marijuana in the past 12 months. A considerable percentage of women who used marijuana in the past year were daily users, met abuse and/or dependence criteria, and were polysubstance users. Comprehensive screening, treatment for use of multiple substances, and additional research and patient education on the possible harms of marijuana use are needed for all women of reproductive age.

Estimates of smoking before and during pregnancy, and smoking cessation during pregnancy: comparing two population-based data sources.

Objectives. We compared three measures of maternal smoking status—prepregnancy, during pregnancy, and smoking cessation during pregnancy—between the Pregnancy Risk Assessment Monitoring System (PRAMS) questionnaire and the 2003 revised birth certificate (BC). Methods. We analyzed data from 10,485 women with live births in eight states from the 2008 PRAMS survey, a confidential, anonymous survey administered in the postpartum period that is linked to select BC variables. We calculated self-reported prepregnancy and prenatal smoking (last trimester only) prevalence based on the BC, the PRAMS survey, and the two data sources combined, and the percentage of smoking cessation during pregnancy based on the BC and PRAMS survey. We used two-sided t-tests to compare BC and PRAMS estimates. Results. Prepregnancy smoking prevalence estimates were 17.3% from the BC, 24.4% from PRAMS, and 25.4% on one or both data sources. Prenatal smoking prevalence estimates were 11.3% from the BC, 14.0% from PRAMS, and 15.2% on one or both data sources. The percentages of prepregnancy smokers who indicated that they quit smoking by the last trimester were 35.1% from the BC and 42.6% from PRAMS. The PRAMS estimates of prepregnancy and prenatal smoking, and smoking cessation during pregnancy were statistically higher than the corresponding BC estimates (t-tests, p<0.05). Conclusions. PRAMS captured more women who smoked before and during the last trimester than the revised BC. States implementing PRAMS and the revised BC should consider information from both sources when developing population-based estimates of smoking before pregnancy and during the last trimester of pregnancy.

Smoking patterns and use of cessation interventions during pregnancy.

BACKGROUND Pregnant smokers should be counseled to quit smoking and offered effective cessation interventions. To improve understanding of how best to increase smoking-cessation rates during pregnancy, this study analyzed population-based surveillance data to describe womens smoking patterns and the use of cessation services during pregnancy. METHODS Data were analyzed from the 2004 and 2005 New Jersey Pregnancy Risk Assessment Monitoring System, a population-based survey of postpartum women (n=4473). Measures of behaviors included the timing of quit relative to the learning of pregnancy, provider assistance, the use of cessation interventions, and barriers to quitting. Analyses were done in 2007 and 2008. RESULTS An estimated 16.2% (95% CI=15.1, 17.3) of women smoked before pregnancy. Of these, 49.8% quit before entering prenatal care, and 5.2% quit after entering prenatal care. Almost all women reported that their prenatal care provider asked if they smoked, but only 56.7% reported that a provider counseled them to quit smoking. Only 11.5% of women who smoked in late pregnancy used a cessation method, including self-help materials (6.3%); medications (3.9%); face-to-face counseling (1.7%); telephone-based counseling (1.5%); Internet-based counseling (1.3%); and a class or program (1.0%). The most frequently reported barriers to quitting were cravings for a cigarette, stress, and being around people who smoked. CONCLUSIONS Nearly half of pregnant New Jersey smokers quit before prenatal care, and very few quit later. Few continuing smokers used a smoking-cessation method when trying to quit or cut back. Efforts should be intensified to increase the knowledge, promotion, and referral to effective interventions to help pregnant smokers quit.

Reducing Prenatal Smoking: The Role of State Policies

BACKGROUND Maternal smoking causes adverse health outcomes for both mothers and infants and leads to excess healthcare costs at delivery and beyond. Even with substantial declines over the past decade, around 23% of women enter pregnancy as a smoker and though almost half quit during pregnancy, half or more quitters resume smoking soon after delivery. PURPOSE To examine the independent effects of higher cigarette taxes and prices, smokefree policies, and tobacco control spending on maternal smoking prior to, during, and after a pregnancy during a period in which states have made changes in such policies. METHODS Data from pooled cross-sections of women with live births during 2000-2005 in 29 states plus New York City (n=225,445) were merged with cigarette price data inclusive of federal, state, and local excise taxes, full or partial bans on smoking in public places, and tobacco control spending. Probit regression models using a mixed panel, state fixed effects, and time indicators were used to assess effect of policies on smoking (during 3 months before pregnancy); quitting by last 3 months of pregnancy; and having sustained quitting at the time of completing the postpartum survey. RESULTS Multivariate analysis indicated that a