What Chemicals Are Present in Secondhand Vape Emissions? What Chemicals Are Present in Secondhand Vape Emissions? 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 Exposure to Thirdhand Smoke Harms the Health of Pregnant Women Thirdhand Smoke Resource Center Vaping and Pregnancy: Are E Cigarettes Really Any Safer for You and Your Baby? E Cigarettes and Pregnancy Maternal Infant Health CDC