Age Cap Boosts Pregnant Teens Using e-Cigarettes

The law places age limits on the purchase of e-cigarettes to reduce the use of tobacco products but a recent study shows an unintended consequence - a rise in traditional cigarette smoking among pregnant teens. However, researchers found the increase in cigarette smoking did not result in any negative birth outcomes.

The study was conducted by researchers at Princeton University and Cornell University. They examined around 500,000 births among teenagers in the United States and found a 19.2 percent increase in cigarette smoking among pregnant teenagers including those who are underage and a 13.8 percent increase among underage pregnant teens after the enactment of minimum sale ages for e-cigs.

In the United States, every state already has it age limits on traditional cigarette sales, and so substitution between e-cigarettes and the traditional cigarettes will not be possible if these limits are perfectly enforced. Hence, the findings of the new study suggest that limits on e-cigarettes are more binding on minors and teens usually substitute one type of cigarettes for another.

"Traditional cigarette use typically declines during pregnancy, but our results show that laws limiting access to e-cigarettes actually slows down this decline, presumably because women are prevented from switching to e-cigarettes," Henry Putnam Professor of Economics and Public Affairs and chair of the Department of Economics at Princeton and co-author of the study, Janet M. Currie said.

Many states enacted laws to limit access to electronic nicotine delivery systems following the findings of national surveys that 2014 was the first year that teens made a dramatic shift away from traditional tobacco products to devices like e-cigarettes, vape pens, personal vaporizers, e-cigars and e-hookahs among others, according to Medical Express.

Two previous studies suggest that traditional cigarette smoking rises among teens when these laws are implemented, which motivated Currie and her colleague to study how age-specific policies limiting access to e-cigs may have influenced smoking of traditional cigarettes among pregnant teens.

In the study, the authors evaluated 547,176 birth records obtained from the National Center for Health Statistics (NCHS). They compared the data of women who gave birth before the age of 18, who faced new limits and those who gave birth at the age of 19, who would have been able to purchase the devices legally throughout their pregnancy in most states.

The two study groups conceived between 2010 and 2014 - when information on both traditional and e-cigs use on birth records was complete. Among the study participants, 40.8 percent were pregnant women under age of 17 years, and 59.2 percent were 19 years old.

The researchers analyzed the data along with the laws placing age limits on access to e-cigs provided by the Centers for Disease Control and Prevention (CDC). They found that 14 percent of women in the 19-year-old group smoked cigarettes during their pregnancy compared to 7.3 percent of the 17-year-old group. The researchers said the fact that most 19-year-olds can legally purchase cigarettes in many states accounts for this difference, according to Science Daily.

The age limit policy had the greatest effects on young pregnant women, as the average underage pregnant woman smoked about a half a cigarette extra per day following the enactment of the law. In states that passed the law, 13.7 percent of the study participants smoked traditional cigarettes in the three months before conceiving, 12.4 percent in the first trimester, 11.3 percent in the second trimester and 11.1 percent in the third trimester.

The rates were found to be higher in locations with the law than those without. The researchers published their findings as a working paper in the National Bureau of Economic Research (NBER).