It’s not healthy to smoke during pregnancy but an estimated 12% to 24% of pregnant women continue to use tobacco, according to national data [PDF]. So if the existing evidence hasn’t convinced them to quit, perhaps this new study will: a researcher from the Loma Linda University School of Medicine reports that fetal exposure to nicotine may be associated with increased blood pressure among children once they grow up.
Granted, the study measured nicotine’s effects on rat fetuses rather than developing humans. But if the association holds up in people, we should be concerned about the hearts of babies born to smoking mothers.
Previous studies in humans has shown that children born to smoking mothers have suffer from damage to their vascular, or blood-vessel system, but it’s impossible to prove the correlation given confounding factors. So DaLiao Xiao, assistant research professor of basic sciences at Loma Linda set out to test the association in rats. In an experiment, he gave 12 pregnant rats a daily dose of intravenous nicotine and 13 different pregnant rats a saline placebo. He then monitored their offspring for up to five months for signs of heart damage or other circulation problems. At five months, the offspring of the rats who were given nicotine had two classic signs of heightened heart risk: increased oxidative stress and hypertension.
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While we can’t extrapolate that people react the same way as rats — and we can’t extrapolate that a nicotine injection perfectly mirrors the real-world delivery of nicotine through smoking, nicotine gums or patches — the research does highlight how maternal smoking may lead to poor cardiovascular outcomes for children. Lighting up doesn’t just affect the mother-to-be, but those cigarettes could leave a lasting health legacy on her kids as well.
Meredith Melnick is a reporter at TIME. Find her on Twitter at @MeredithCM. You can also continue the discussion on TIME’s Facebook page and on Twitter at @TIME.