Animal Study Shows Harmful Effects of Secondhand Smoke Even Before Pregnancy Duke Health Vape Residue May Harm Unborn Babies' Immune Systems Respiratory Therapy Second hand vape smoke linked to more asthma symptoms in kids Second hand smoke poses significant risks not only to adults but also to unborn babies. Eliminating exposure to second hand smoke during pregnancy is essential for the health of both mother and child, as Vaping more effective than patches for pregnant women, study finds Dr Colin Mendelsohn E Cigarettes and Pregnancy Maternal Infant Health CDC