Most health care providers encourage women who smoke and are pregnant to stop smoking. However, until recently, the impact of second-hand smoke was not fully known or understood. That situation has now changed.

Studies Show Harmful Impact of Second Hand Smoke

A recent study reveals the potential harm that can be caused to the unborn from second-hand smoke, even prior to conception.

Researchers at Duke University used rats in experiments that were designed to mimic the second-hand smoke exposures which humans encounter, and they found that the chemical components of tobacco smoke affect fetal brain development throughout pregnancy. Although their findings showed that the impact was most severe with exposures occurring in later pregnancy stages, they also discovered that adverse effects on the fetuses’ neuro-development occurred even when the mothers were only exposed prior to conception. The smoke exposure damages regions of the baby’s brain which are involved in learning, memory, and emotional responses.

“This finding has important implications for public health, because it reinforces the need to avoid second-hand smoke exposure not only during pregnancy, but also in the period prior to conception, or generally for women of childbearing age,” said Theodore A. Slotkin, Ph.D., professor in Duke’s Department Pharmacology & Cancer Biology.

The research findings were published in the January issue of the journal Toxicological Sciences.

Another report, published in 2014, indicated exposure to second-hand smoke was linked to pregnancy loss, including miscarriage and stillbirth. This study, conducted by researchers at the University of Buffalo and Roswell Park Cancer Institute, also showed a high risk for nonsmokers who were exposed to second-hand smoke.

“This study demonstrated that pregnancy outcomes can be correlated with second-hand smoking. Significantly, women who have never smoked but were exposed to second-hand smoke were at greater risk for fetal loss,” said Andrew Hyland, PhD, chair of Roswell Park’s Department of Health Behavior and the study’s lead investigator.

Experts believe there are about 4,000 chemicals in second-hand smoke, many of which can be cancer-causing. Toxins can enter a person’s bloodstream when they breathe in the residue of cigarettes and cigars. Therefore, in order to reduce your risk to exposure if you are pregnant, it’s best to avoid smoke and smoking all together.

The Problem with Smoking and Smoke Exposure

The Centers for Disease Control (CDC) has long affirmed that smoking while pregnant is harmful to both the mother and her unborn. For example, smoking causes cancer, heart disease, and other significant health problems in adults and can cause premature birthbirth defects, and infant death. Additionally, women who smoke during pregnancy are more likely than other women to have a miscarriage. Even e-cigarettes are not safe to use during pregnancy because they contain nicotine, known to be a health danger for pregnant women and developing babies (impacting the unborn’s brain and lungs). Also, some of the flavorings used in e-cigarettes may be harmful to a developing baby.

If you’re a pregnant woman and you smoke, please try to quit. There are many resources to help you, including these websites:

You can also call 800-QUIT-NOW (800-784-8669).

For better health for you and your baby, stop smoking and avoid smoke from others’ habit. You may also need to ask your companion, friends, and family members to refrain from smoking around you while you’re pregnant.