Australian researchers believe they have found the first evidence that women who smoke while pregnant affect their child's cardiovascular health for years to come.
The University of Sydney study found pre-natal exposure to a mother's smoking decreased the amount of good cholesterol in children, which may increase their risk of eventual heart attacks and strokes by up to 20 per cent.
It was already common knowledge that smoking while pregnant was harmful, but even so, this study yielded more significant results than the scientists were expecting.
David Celermajer, a professor of cardiology at the University of Sydney, says he was "gobsmacked".
He and his colleagues studied 328 healthy eight-year-olds and found some bore the lingering imprint of their mother's pregnant smoking.
"Most studies suggest that if you stop smoking, eight years later a lot of your risk has reduced," he said.
"The reason we were gobsmacked is here are kids who were exposed to another person's smoke when they were growing in their mum's belly and eight years later, eight years after being removed from that ... they've still got a footprint on it," he said.
"That's the staggering part. To the best of my knowledge no-one has ever shown before that smoking [while] pregnant has a prolonged effect on body changes in offspring."
The results of the study, published today in the European Heart Journal, relied on questionnaires about the mother's smoking habits filled in shortly after the children's birth, and blood samples from the children.
The researchers found the children whose mothers reported smoking while pregnant had less high-density lipoprotein (HDL) or so-called "good cholesterol" than children whose mothers had not smoked.
HDL protects against heart disease and stroke.
The study found the smoking mother's children have 1.3 millimoles per litre of HDL compared to a more normal level of 1.5.
Professor Celermajer says the difference is "very significant".
"Heart disease remains the number one killer in Australia, so even a small increase in risk above the general population represents a massive number of people that are potentially affected," he said.
"Roughly, for every 1 per cent reduction in the good cholesterol, there's a 1 per cent increase in heart attack risk.
"And what we've found in this study is up to a 20 per cent reduction in the good cholesterol levels of these children of mums who have smoked during pregnancy ... so we postulate that they're up to 20 per cent risk higher of heart attack and stroke during their lifetimes."
Professor Celermajer said the researchers were looking to find out whether smoking in pregnancy was related to high blood pressure in children.
"And it wasn't. We also looked as to whether smoking in pregnancy actually caused the blood vessels to thicken up. And it didn't," he said.
"But we suspect that may be because these kids [are] only eight years old and that these are things that may turn out to be the case in future, but we obviously have to follow up these children longer."
Professor Celermajer says the study results are not just a wake-up call for mums-to-be, but should lead everyone to contemplate their own mothers' habits.
"For kids whose mums did smoke - and they can't wind back the clock now - they have to be particularly careful of the way they live their lives to maximise their heart health, by not smoking themselves and by having healthy diet and exercise habits," he said.
"So there's a real take-home message for the kids too, not just for the mums."
Are u for real??
I don't know how anyone can knowingly do it and not feel immense guilt. 
