Vaping may alter a baby’s skull shape in the womb, according to researchers.
Exposure to two liquid ingredients in the e-cigarettes used to create vaping’s throat hit and smoke plume were tied to the changes – even without the addiction-driving nicotine.
“This had no nicotine, and it’s still having effects on the development of the skull in our model, which was not anything we expected,” Dr. James Cray, a professor of anatomy in The Ohio State University College of Medicine, said in a statement.
To reach these conclusions, Cray and his team studied the effects in pregnant mice. The mice were either exposed to filtered free air or the two substances at differing concentrations. Some were given 50 percent each of propylene glycol and glycerol (the two liquid ingredients), or 30 percent of propylene glycol and 70 percent glycerol.
During their roughly 20-day pregnancy, the mice were exposed to vaping conditions at a rate of one puff each minute for four hours during the course of five days every week.
Then, their pups’ skulls were scanned two weeks after birth, measuring cranial width and height. They found that there were “statistically significant” reduced measurements in the mice exposed to the 30 percent and 70 percent mixture compared to those exposed to free air and the 50 percent formula.
Cray, the lead author of the work, noted that because propylene gylcol had been linked to an increased uptake of nicotine, “a lot of companies have moved toward getting away from a high percentage of propylene glycol toward more glycerol, trying to position this as a safer alternative.”
The researchers had believed that heavier propylene glycol should be causing more effects but he said it was “the exact opposite.”
The results were consistent across several litters of mice in both biological sexes.
“What we see is a consistent narrowing of all of the facial features, and the same thing as we move back into the cranium as well. So globally they’re narrower and a little bit shorter-headed, which does mimic some observable changes that we see in children,” Cray explained.
“We also saw a bit of a reduction in weight. These animals were within the normal range of an animal that age, but they still weighed less,” he said.
Funded by the Ohio State colleges of Medicine and Dentistry, the research was recently published in the journal PLOS One.
Researchers are continuing to examine the health effects of e-cigarettes.
“The majority of users are young adults and teenagers, so we are talking about people who are in peak reproductive years. And with development of the head happening very early in fetal development, people could be using these products and not even realize that they are pregnant, which is of great concern,” Cray added.
“This is a small study that speaks to the possibility that nicotine-free vaping is not safe. And it’s a sign that we probably should study the nicotine-free products as much as we study the nicotine-laden products,” he said.
