June 27, 2011

Smoking While Pregnant Affects Baby’s Cholesterol

(Ivanhoe Newswire) -- New research reveals another reason moms-to-be may want to quit smoking. Babies of women who smoke during pregnancy have lower levels of high-density lipoprotein (HDL) -- the good cholesterol that is known to protect against heart disease later in life.

Smoking during pregnancy has been linked to many childhood health problems including behavioral problems, neuro-cognitive problems, and sudden infant death. However, it has been unclear what effect prenatal cigarette smoking had on a child's risk of cardiovascular disease.

Australian researchers found that by 8 years of age, children born to moms who smoked while they were pregnant, had HDL cholesterol levels that were about 1.3 millimoles per litre compared to the more normal levels of 1.5 millimoles per litre among children who were born to mothers who did not smoke.

"Cholesterol levels tend to track from childhood to adulthood, and studies have shown that for every 0.025mmol/L increase in HDL levels, there is an approximately 2-3% reduction in the risk of coronary heart disease. If we extrapolate this, we can suggest that the difference of 0.15mmol/L between children of smoking mothers versus non-smoking mothers might result in a 10-15% higher risk for coronary disease in the children of smoking mothers. This is an approximation only, but the best one we have," Professor David Celermajer, from the University of Sydney, was quoted as saying.

The investigators studied a group of 405 healthy 8-year-olds who were born between 1997 and 1999. They collected data before the children were born and as they grew up. This included information on the mothers' smoking habits; the children's exposure to passive smoking; and measurements of height, weight, waist circumference and blood pressure.

The link between prenatal smoking and cholesterol remained significant even after adjusting for factors such as postnatal smoke exposure, duration of breastfeeding, physical inactivity and body mass index. The researchers say the prevalence of smoking during pregnancy is still high. In fact, it's around 15 percent in many Western countries. 

"Children born to mothers who have smoked during pregnancy will need to be watched particularly carefully for other coronary risk factors, like high blood pressure, high LDL, 'bad' cholesterol levels, and especially cigarette smoking themselves," Professor Celermajer said.

SOURCE: European Heart Journal, June 2011