Smoking during pregnancy may be linked to ADHD in children

Children born to women who smoked during pregnancy appear to have an increased risk of developing attention-deficit/hyperactivity disorder (ADHD), according to new research. The new study also hints -- but doesn't prove -- that nicotine-replacement products used during pregnancy, such as patches and gum, could pose the same risk to children. Still, this study suggests that nicotine itself, not just tobacco, may be a hazard during pregnancy. Continue reading below... "We've been lulled into a false sense of security, thinking that if we can just get mothers to stop smoking and onto nicotine replacement, it will protect against any kinds of fetal damage in the developing child. This is a stark injection of reality about how that may not be the case," said Dr. Timothy Wilens, director of the Center for Addiction Medicine and acting chief of child psychiatry at Massachusetts General Hospital in Boston. Researchers have long tried to pinpoint the hazards of smoking during pregnancy. Among other things, lighting up during pregnancy seems to boost the risk of miscarriage, pregnancy complications, premature deliveries, low birth weight and even obesity in the child's life, said study lead author Dr. Jin Liang Zhu, an assistant professor of epidemiology at Aarhus University in Denmark. It's not clear how smoking and nicotine use in mothers may affect the brains of developing fetuses. Zhu said nicotine may cause abnormalities in the brain, while the products of cigarette smoke -- such as carbon monoxide -- could affect the brain, too. It's also possible that other factors are behind the association between smoking in pregnancy and ADHD in children, the study authors suggested. ADHD tends to run in families, and people in families with ADHD are more likely to smoke. So, it's possible that the association seen in this study isn't a direct cause of expectant mothers' smoking, but may be the result of genetics or a shared environment where smoking is present, according to background information in the study. ADHD is a common behavioral disorder in childhood, according to the U.S. Centers for Disease Control and Prevention. Symptoms include difficulty paying attention, impulsive behavior and problems with sitting still and getting along with others. Previous research has already linked ADHD in children to mothers who smoked during pregnancy, noted Wilens, who was not involved with the study. In the new study, researchers examined the medical records of nearly 85,000 children born in Denmark to mothers who were recruited to be part of the study from 1996 to 2002. Signs of ADHD were present in slightly more than 2,000 children. The numbers were lower among kids of nonsmoking parents (1.8 percent) and in households where mom quit smoking and dad was a nonsmoker (2 percent). The rates of ADHD were highest among kids in families in which both parents smoked -- 4.2 percent. Read more ...

Women who smoke during pregnancy may affect their future grandchildren's health

Women who smoke while pregnant may not only cause health problems for their children – but also their children’s children. Research suggests the dangers can spill down the generations, with a smoker’s grandchildren also more likely to suffer from asthma. Experts believe the harm caused by smoking in pregnancy can ‘switch on’ bad genes, which are then passed on. During pregnancy, nicotine can affect a baby’s developing lungs, predisposing the infant to childhood asthma. Although this risk is well-known, researchers from Harbor-UCLA Medical Center in California in the US wanted to investigate the implications for future generations. They tested the effect of nicotine exposure during pregnancy on rats, looking not only at their pups, named F1, but also at second generation pups, F2. The researchers found exposure inside the womb resulted in F1 offspring having reduced lung function consistent with asthma. However, it also impaired lung function of F1’s offspring F2, even though the F1 rats were not exposed to nicotine once they were born. A gene function associated with normal lung development was also reduced in both generations of offspring, says a report published in the journal BMC Medicine. Dr Virender Rehan, who led the study, said: ‘When we looked at the effect of nicotine on DNA in the testes or ovaries of the rats they found that nicotine increased the level of methylation in the testes but reduced it in the ovaries. ‘Nicotine also altered methylation of histone proteins in a sex-dependent manner. ‘These epigenetic marks may be the mechanism behind how nicotine-induced asthma is transmitted from one generation to the next.’ He said asthma is the most common chronic disease of childhood and while there are many factors which contribute to asthma, maternal smoking during pregnancy is an avoidable risk. ‘The effects of smoking during pregnancy are, it seems very long lasting’ he added. ‘Stop smoking education and intervention aimed at mothers-to-be and women planning pregnancy needs to take into account the fact that nicotine itself contains dangers to their children and their children’s children.’ Article: 30th October 2012 www.dailymail.co.uk