Since age restrictions on e-cig purchase were passed by states, teenage women have smoked more in those states during pregnancy.
A new study from scientists at Princeton and Cornell universities says that although bans on sales to minors were intended to reduce tobacco use, they actually increased smoking among young pregnant women instead. That’s probably because age restrictions are more strictly observed by vape shops than by traditional cigarette sellers like convenience stores and gas stations.
The researchers analyzed more than a half million birth records in the U.S.provided by the National Center for Health Statistics (NCHS). They compared women who gave birth before their 18th birthday – who faced new limits on purchases of e-cigarettes – with women giving birth at age 19, who would have been able to purchase vape products legally throughout the full length of their pregnancy in most states.
Both groups conceived their children between 2010 and 2014, a period during which information about smoking and vaping on birth records was more complete than it is now. The researchers matched the data from the birth records with state and local laws restricting the age of purchase for vapor products. They controlled for variable factors like tax rates and workplace smoking restrictions.
The authors say their findings suggest that age restrictions on e-cigarettes make them harder to get than cigarettes, even though cigarettes are equally illegal to sell to minors. Most women reduce their cigarette smoking during pregnancy more than those in the study did. These figures suggest that laws restricting who can buy e-cigs cut by half the reduction in cigarette consumption that pregnant minors would typically exhibit during the first trimester.
The study illustrates the need for more data to properly determine how age restrictions on vapor products influence maternal and infant health, according to the researchers. “At present, birth records record traditional cigarette use but ignore electronic nicotine delivery systems. We believe states should collect data on both,” co-author Michael Pesko said in a press release. “States may also wish to consider adding questions on other sources of nicotine exposure, such as through the use of nicotine replacement therapy.”
The findings have been published as a working paper by the National Bureau of Economic Research (NBER).