(RxWiki News) It's no secret that smoking during pregnancy can lead to low birth weight or even miscarriage. But new research suggests smoking while pregnant can also affect children later in life.
Researchers from the University of Sydney in Australia have found that mothers who smoke while pregnant can cause developmental changes in their unborn babies that lead to lower levels of "good" HDL cholesterol. Short for high-density lipoprotein, the type of cholesterol is known to protect against cardiovascular disease later in life.
"Don't smoke during pregnancy."
The research revealed that by the age of eight years old, children born to mothers who smoked while pregnant had HDL cholesterol levels of about 50.2 mg/dL compared to an average level of 57.9 mg/dL in children whose mothers were non-smokers. After adjustments for various factors such as post-natal smoke exposure, the difference attributable to mothers who smoked was determined to be 5.8 mg/dL.
Researchers said the effect was the same even if children had been exposed to smoke following birth, suggesting that prenatal exposure had the largest impact on lower HDL later.
The research was recently published online in the European Heart Journal.
David Celermajer, Scandrett professor of cardiology at the University of Sydney, who led the study, said the results show that smoking while pregnant "imprints" an unhealthy sets of characteristics while children are developing in the womb, which may later predispose them to higher risk of heart attacks and strokes. He said the imprinting lasts at least eight years, but could last much longer.
Researchers examined the effects of maternal smoking during pregnancy on the thickness of the arterial wall and the levels of lipoproteins in a group of 405 healthy eight-year-olds born between 1997 and 1999. The children were enrolled before birth into a random controlled trial investigating asthma and allergic diseases.
Researchers collected information before the children were born and as they grew up, including information on mothers' smoking habits before and after pregnancy, the children's exposure to passive smoking, and measurements of height, weight, waist circumference and blood pressure.
Ultrasound scans were used to measure the arterial wall thickness and, in 328 children who agreed, they took blood to test cholesterol levels. There was no effect on the thickness of the children's arterial wall.
The research suggests that the lower levels of HDL cholesterol at that age could cause a serious impact later in life and that the children will likely also have low levels in adulthood.
Celermajer suggested that the lower HDL levels could put the children at a 10 to 15 percent higher risk for coronary disease.