Animal Study Shows Harmful Effects of Secondhand Smoke Even Before Pregnancy Duke Health Hidden Dangers of Secondhand Vaping Emory Health Digest Vaping doesn't harm pregnant women or babies: shocking study Is Vaping Better Than Smoking? American Heart Association Health Risks of Secondhand Smoke and Aerosols Factsheet US EPA 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