Pregnant women who smoked had babies with blood pressure problems throughout their first year of life, according to a new study published in Hypertension, HealthDay News reports.

For the study, researchers from the Karolinska Institute in Stockholm compared 19 babies of nonsmoking couples with 17 infants of women who smoked an average of 15 cigarettes a day while pregnant.

Researchers found 1-week-old infants of smoking mothers had a 10 percent spike in blood pressure and a 4 percent boost as 1-year-olds. These children also had abnormal and exaggerated heart rate response when they were tilted.

“The extent of the condition at one year suggests that it is not going to disappear quickly,” said Gary Cohen, a senior research scientist in the institute’s department of women and child health. But researchers didn’t know whether these abnormalities would later lead to trouble for these kids.

The reason tobacco exposure affects blood pressure in babies is unclear, Cohen said.

But what is clear from other studies is that tobacco smoke produces a similar kind of damage in babies born to drug-using moms.

“When we isolated tobacco effects, we showed that there are inborn neural effects of tobacco exposure similar to what we see in cocaine and methamphetamine abuse,” said Barry M. Lester, a professor of psychiatry and pediatrics at Brown Medical School in Providence, Rhode Island.

Other research has connected these neural problems to overproduction of cortisol, a stress hormone that regulates blood pressure and the immune system.
“There is a lot of evidence showing that too much cortisol is damaging,” Lester explained.

Until more evidence becomes available, however, the bottom line is lay off the cigarettes, researchers advise.

This is especially important because treatment for children exposed to tobacco smoke “does not seem possible,” Cohen said.
“The best intervention to solve these problems is prevention,” Cohen said. “Women who are pregnant need to avoid exposure to tobacco smoke in the air. Passive smoke exposure can be as bad as being an active smoker.”

Learn how expecting mothers can lower their stress and blood pressure to help their newborns’ health here.