E-Cigarette Use Among Pregnant Women: A Need for Better Measurement

Rates of cigarette smoking during pregnancy in the United States are much higher than global rates of smoking during pregnancy (7.2% vs. 1.7%). ¹ However, the patterns of e-cigarette use among pregnant women remain unclear. E-cigarettes can be a harm reduction option for the general population, but pregnant women have unique considerations given that nicotine can be harmful to their unborn child, leading to adverse consequences such as low birth weight, small for gestational age neonates, or preterm birth. ² The Centers for Disease Control (CDC) recommend pregnant women discontinue e-cigarette use. ³ However, there is inadequate measurement of e-cigarette behaviors among pregnant women, precluding researchers, clinicians, and policymakers from making informed regulatory decisions, and providing resources pregnant women may need to quit using e-cigarettes during pregnancy.

The Pregnancy Risk Assessment Monitoring System (PRAMS) is a surveillance study conducted by the CDC that assesses health behaviors right before, during, and immediately after pregnancy for the purpose of informing policies to reduce maternal and infant mortality rates. ⁴ Participating sites include 46 states, the District of Columbia, New York City, Northern Mariana Islands, and Puerto Rico. ⁵ While the core questionnaire for PRAMS has included items related to e-cigarettes, these items provide limited information. There was an e-cigarette supplement that included detailed questions about e-cigarette use (e.g., lifetime and recent use, motives for use, harm perceptions, etc.), but this supplement was only used for 1 year (2015) at just two sites.

Previous recommendations have been published related to e-cigarette questions to be included in surveillance studies ⁶ ; however, these recommendations did not specifically include measurement of pregnant women. We have specified suggestions for assessment of e-cigarettes in the next PRAMS phase, which will be established in the next 2 years. Given the limited space available for the vast number of topics covered in the PRAMS questionnaire, we have been judicious in our recommendation in hopes that these items will be adopted within the core questionnaire.

First, capturing more detailed information regarding timing of e-cigarette use in relation to pregnancy is important for comparability to other population-based studies and for understanding patterns of use. Questions in the current Phase 9 core questionnaire assess e-cigarette use in the past 2 years, 3 months before pregnancy, and during the last 3 months of pregnancy. However, data related to lifetime use is not obtained, which may facilitate a better understanding of past behaviors. Additionally, lifetime use is a standard item across population-based studies such as the Behavioral Risk Factor Surveillance System (BRFSS) and the Population Assessment of Tobacco and Health (PATH) studies, and may be a beneficial replacement for the current question inquiring about e-cigarette use in the past 2 years. ⁶

Additionally, assessing e-cigarette use in the 3 months before pregnancy and last 3 months of the pregnancy fails to measure e-cigarette use in the first or second trimester, making it difficult to have a full picture of quit attempts or relapses during pregnancy. Fetal exposure to e-cigarettes during the last 3 months of pregnancy has been associated with adverse birth outcomes, ⁷ and identifying who is at risk for continued e-cigarette use or relapse over the course of pregnancy is important for developing tailored interventions to reduce these exposures. Adding a question about use during the first and second trimesters may provide more information about lapses and relapses during pregnancy.

The language used in questions about e-cigarettes should also be carefully considered. Specifically, the current questionnaire refers to products as “e-cigarettes,” “vapes,” and “electronic nicotine products.” However, many people may not believe their product fits this category as they have different language they use (e.g., “vaping,” “juuling”). ^7,8 Thus, presenting a variety of options and providing specific brand name examples for recognition by a wider audience may help capture these behaviors for more individuals. ⁷

Third, the Phase 9 core questionnaire is limited in how it asks about motives for using e-cigarettes. The Phase 9 core questionnaire added a question from its previous iteration to inquire if women had used an e-cigarette in the past 2 years “as a way of cutting down or stopping cigarette smoking” with dichotomous answer options. However, this item does not capture other motives for use salient to pregnant women. The 2015 e-cigarette supplement assessed a wider breadth of motives for use (e.g., believing that e-cigarettes are less harmful to themselves or their baby, using for flavors). It may be beneficial to expand the “motives for use” question in the next version to more closely resemble the question used in the supplement. It may also be helpful to clarify the timing of e-cigarette use within the question, as the e-cigarette supplement motives question does not specify a timeframe. By specifying that the question is asking why a participant is using an e-cigarette during pregnancy, researchers may learn more about the specific beliefs or needs of these women at this important time in their lives.

Lastly, e-cigarettes may also be used as a delivery system for other substances such as cannabis. Clarifying in the instructions that e-cigarette questions are only asking about e-cigarette liquids with nicotine may help participants better answer the questions in a consistent way. However, given that cannabis use via e-cigarettes has become prevalent in the general population, ⁹ and this behavior can negatively impact fetal development, ¹⁰ it may be helpful to include questions related to using other substances in e-cigarettes. Without this information, the scope of the problem of pregnant women using e-cigarettes to deliver other substances remains unclear, and thus resources are not being devoted to addressing this risky behavior.

Current large-scale surveillance studies such as PRAMS are an excellent opportunity for learning more about e-cigarette behaviors among pregnant women as it poses unique risks to the health of developing fetuses. Asking more targeted questions in these four ways may help researchers, clinicians, and policymakers to make informed decisions about regulations and how to best provide care for pregnant women using e-cigarettes.