Vaping reduces toxic chemical exposure in pregnancy

Pregnant women who vape are exposed to lower levels of toxic chemicals than those who smoke, new research led by scientists at City St George’s, University of London has found.

The study recorded reductions ranging from 44 per cent to 97 per cent in levels of harmful substances among women who exclusively vaped compared with those who exclusively smoked.

Researchers analysed 14 volatile organic compounds (VOCs) – toxic chemicals inhaled when smoking or vaping that are linked to cancer, respiratory disease and cardiovascular conditions – using urine samples collected from 140 pregnant women at five hospitals across the UK.

The research is the first to rigorously compare exposure to toxic chemicals from smoking and vaping during pregnancy.

Participants were divided into five groups: those who exclusively smoked (38), who only vaped but previously smoked (35), who smoked and vaped (25), who smoked while using nicotine replacement therapy (10), and those with no history of using any nicotine or tobacco products (32).

Urine samples were taken during routine antenatal appointments and tested for levels of nicotine and harmful substances. Of the 14 VOCs assessed, 10 were found to be significantly lower in women who exclusively vaped compared with those who exclusively smoked.

Researchers also found that levels of 13 VOCs were similar in women who exclusively vaped and those who had never used nicotine or tobacco products.

“Just because mothers-to-be are exposed to fewer harmful chemicals by opting to vape instead of smoking cigarettes, does not mean vaping during pregnancy is safe,” said Professor Michael Ussher, professor of behavioural medicine from the School of Health and Medical Sciences at City St George’s, University of London, who led the study. Understanding exposure to these toxins in pregnant women is only one half of the picture. We’re now embarking on the most rigorously designed study, to date, to look at whether vaping during pregnancy has any harmful health outcomes for mother or baby.”

Although the researchers examined the major known toxins at the time the study began, they noted that some toxins were present at similar levels in both smokers and vapers. They also warned that other harmful substances not included in the analysis may be present in vaping products.

“Vaping products are constantly evolving, and so we need to keep an eye on any new toxins that we need to check for. It’s an ever-evolving field of research,” Professor Ussher added.

Stopping smoking during pregnancy remains a key health priority for both mother and baby, with more women choosing to vape as a method of quitting. Until now, there has been limited reliable data on exposure to harmful substances from vaping during pregnancy.

The research was carried out in collaboration with the University of Nottingham, University College London, King’s College London, the US Centers for Disease Control and Prevention and the UK Health Security Agency. It was funded by Cancer Research UK.