(CNN) -- About one in 14 pregnant women who gave birth in the United States in 2016 smoked cigarettes during her pregnancy, according to a report released Wednesday.
The findings, gathered by the Centers for Disease Control and Prevention's National Center for Health Statistics, revealed that 7.2% of all expectant mothers smoked -- but that the percentage of pregnant smokers varied widely from state to state.
The prevalence of smoking was highest in West Virginia, where 25.1% of women reported smoking at any time during pregnancy, and lowest in California, where 1.6% reported smoking.
"Despite the well-understood risk to mother and child, still, about one of every 14 women in the United States smoked during pregnancy," said Patrick Drake, senior author of the report and a demographer at the CDC's National Center for Health Statistics.
"These levels do vary widely by state, maternal age, race and Hispanic origin, and education, but any amount of smoking during pregnancy is too much," he said.
In 2011, about 10% of women in the US reported smoking during their last three months of pregnancy, and of those women who smoked, 55% quit during pregnancy, according to data from the CDC's Pregnancy Risk Assessment and Monitoring System.
Smoking while pregnant puts a baby at risk for certain birth defects. It also can cause a baby to be born too early or to have low birth weight, and can raise the risk of stillbirth or sudden infant death syndrome, according to the CDC.