Younger mothers, as well as those less educated, tended to be the biggest offenders, according to the National Center for Health Statistics, leading the organization to suggest smoking cessation counseling for these particular populations as well as anti-smoking ad campaigns targeted towards high-risk groups.

The report, based on data collected in 2016, found Native Americans and Alaska natives were the most likely to smoke during pregnancy, with 16.7% of expecting moms in the two groups still smoking. The largest number of pregnant smokers were in West Virginia (25%), followed by Kentucky (18%), and Montana (16.5%). The lowest rates were in Arizona, California, Connecticut, Hawaii, New Jersey, New York, Nevada, Texas, Utah, and Washington, D.C. with less than 5% of pregnant women smoking in each location, reports CBS News.

Smoking while pregnant can cause a baby to be born premature and triples the risk of Sudden Infant Death Syndrome (SIDS). Children whose mothers smoked while they were pregnant are also more likely to develop asthma and have heart defects after birth, according to the Centers for Disease Control and Prevention.

The older a woman was and the higher the level of education she had achieved (for instance, a college education vs. someone who only graduated high school) when she became pregnant, the less likely she was to smoke during that pregnancy.

The report’s authors feel like non-judgmental counseling and “a health care provider’s sensitivity and empathy during coaching and counseling” can help reduce the number of pregnant smokers, and lead to more healthy babies.