There's a laundry list of things to avoid when you're pregnant: taking a sauna, drinking alcohol or more than one cup of coffee a day, and of course, smoking. Most women get that, but not everyone.

An alarming 7.3% of women in the U.S. smoke cigarettes while they’re pregnant, according to a 2016 report from the Centers for Disease Control and Prevention.

And a study published in JAMA Pediatrics last year says that 3.6% of pregnant women are smoking e-cigs, slightly more than the number of nonpregnant women who use them (3.3%). It's possible many don't think vaping is as harmful as regular cigarettes.

But new research published in the American Journal of Physiology-Lung Cellular and Molecular Physiology says that e-cigarettes are associated with an underdeveloped fetal respiratory system and lung disease in adulthood.

While this research was conducted on mice, not humans, it's a clear indication that pregnant women should stay away from e-cigarettes.

If you're pregnant and smoke e-cigarettes, talk to your doctor about how to quit. The earlier in your pregnancy you quit, the better the outcome for your child.

There are smoking cessation tools, including pharmacological options, available to you. Your doctor can help you assess which are safe during pregnancy and most effective.

You can also consider starting cognitive behavior therapy to help you cope with the stress of going smoke-free and keep you focused on your goal of a healthy pregnancy.

If your partner smokes, quit together, because secondhand smoke from any source is harmful to both fetus and mom.