Second hand vaping exposure very low compared to second hand smoking UCL News UCL University College London Vape Residue May Harm Unborn Babies' Immune Systems Respiratory Therapy In the United States, about 8% of all women who are pregnant smoke cigarettes, and another roughly 4% report using electronic cigarettes or vapes. To learn more about the dangers of smoking Health Risks of Secondhand Smoke and Aerosols Factsheet US EPA Smoking during your partner's pregnancy Raising Children Network