Background:Electronic cigarettes (e-cigarettes) are increasingly being used by pregnant women, but little is known about how this affects offspring respiratory development. In previous work, we had found that F1 offspring of e-nicotine-exposed female Drosophila melanogaster were smaller, which carried on into adulthood¹. Here, we investigated in flies how the constituents of a commercially avialable e-cigarette affect the length and morphology of the respiratory tract of fly offspring.

Methods: Virgin female Drosophila melanogaster flies were exposed either to vapored water or base liquid (Propylenglycol /Veg. Glyzerin/ Aqua dest. 55/35/10)with or without nicotine (18mg/ml Nicotine in base solution;Joyetech evic Primo Mini box mod). The exposure was 1 puff/min for 10 min daily over 10 days. After the last exposure, females were mated with non-exposed males and the larval length of offspring was quantified. The total length of their airway terminal cells was measured in the 3rd thoracic segment (Image J, Plugin NeuonJ).

Results: Maternal exposure to base liquid reduced the larval length in F1 males and females by 8% and 6%, respectively. The addition of nicotine to base liquid further reduced larval length to 12% in males, but not in females (6%).  However, the length of the terminal airway cells was more than doubled by base in both males and females.

Conclusion: The reduced size of offspring from e-cig exposed mothers is consistent with data from the US Pregnancy Risk Assessment Monitoring System (PRAMS). The physiological consequences of increased terminal airway cell length and their epithelial structure need further investigation.

¹El-Merhie et al Sci Rep 2021