September 14th, 2009 
Smoking during pregancy increases the risk of a baby developing asthma up to sixfold, said a Swedish study published at the European Respiratory Society’s annual congress on Monday.
The study by Professeur Anders Bjerg of the Sunderby central hospital in Norrbotten and his specialists showed that smoking leads to babies being born underweight, a fact that has an impact on the development of asthma.
The Swedish doctors studied asthma in about 3,400 children between 1996 and 2008.
The study found that babies of smoking mothers had an average weight of 211 grammes (7.44 ounces) less than those of mothers who do not smoke.
Nearly a quarter (24.3 percent) of smoking mothers’ babies weighed less than 2.5 kilogrammes at birth against 4.1 percent for those of non-smoking women.
In underweight children of women who smoked throughout their pregnancy the asthma risk was at 23.5 percent, against 7.7 percent in children of non-smoking mothers who were born with an average weight.
Related
- Neglecting Asthma Treatment During Pregnancy Increases Risk of Asthma in Child
Expectant mothers who eschew asthma treatment during pregnancy heighten the risk transmitting the condition to their offspring, according to one of the largest studies of its kind published in the European Respiratory Journal.
A research team from the Université de Montréal, the Hôpital du Sacré-Cœur de Montréal and Sainte-Justine University Hospital Research Center found that 32.6 percent of children born to mothers who neglected to treat their asthma during pregnancy developed the respiratory illness themselves.
“Uncontrolled maternal asthma during pregnancy could trigger a transient yet important reaction in the fetus that affects lung development and could subsequently increase the likelihood of a baby developing asthma in later childhood,” warns lead author Dr. Lucie Blais, a professor at the Université de Montréal’s Faculty of Pharmacy and researcher at the Hôpital du Sacré-Cœur de Montréal.
As part of the study, the research team examined a decade of health records for 8,226 children – from birth to 10 years of age – born to asthmatic mothers. Parents of these children were also mailed questionnaires requesting additional facts concerning familial medical history, lifestyle habits and environment.
“We found that failing to control maternal asthma during pregnancy clearly has an impact on asthma in offspring – a consequence that is independent of other contributing factors,” says Dr. Blais. “It is of great importance for physicians to adequately treat asthmatic mothers during pregnancy, not only for the favourable outcome of pregnancy but also for the benefit of the child.”
- Smoking while pregnant increases risk of ‘cross eyes’ and reduced fertility in baby
Smoking while pregnant increases the chance of eye problems and low fertility counts in babies, according to two separate scientific studies.
Dr. Tobias Torp-Pedersen and his team of researchers at the Statens Serum Institut in Copenhagen, Denmark found that smoking while pregnant increased the risk of strabismus, a condition in which the eyes are unable to align evenly.
Dr. Torp-Pedersen said that little is known about the origin of the condition, but theorized that chemical disturbance could yield degeneration in the eye muscles and nerves. “Nicotine and other substances in tobacco, alcohol and caffeine all affect the brain in some way,” said Dr. Torp-Pedersen. “Minor disturbances to the developing brain could plausibly lead to strabismus.”
The team reviewed 1,300 cases of strabismus in children born between 1996 and 2003 using data from the Danish National Birth Cohort. Included in the data were interviews with the children’s mothers during and after pregnancy.
“We were able to show that each extra cigarette smoked per day during pregnancy exerted a 5 percent increase in strabismus risk, which is a new finding,” Torp-Pedersen told Reuters Health.
In a second, unrelated study, Professor Richard Sharpe of the Queen’s Medical Research Institute in Edinburgh performed a comprehensive review of numerous medical studies on the effects chemicals and obesity have on the sperm production of male babies.
Sharpe found that a mother’s smoking habits while pregnant had much more of an impact on a male’s sperm production than cigarette exposure outside the womb, later in life. He theorizes that the risk is greater in the womb because toxins in the blood stream reduces the number of sertoli cells, highly specialized cells needed to support the growth of young sperm all the way through to a man’s adult life.
Sharpe was skeptical, however, about how much any individual chemical in the womb contributes to poor sperm development. He did suggest that large “cocktails” of a variety of chemicals may have a combined effect, but more research was required he said.
Dr. Allan Pacey, a Sheffield University expert in male fertility, told the Daily Mail: “This review reminds us that the sperm production capacity of men is probably established quite early in life and perhaps even before they are born. This highlights the importance of women having healthy pregnancies and not exposing their baby to harmful chemicals, such as cigarette smoke.”
Dr. Torp-Pedersen’s research appears in the March issue of American Journal of Epidemiology, while Professor Sharpe’s work appears in the upcoming May 27 issue of Philosophical Transactions of the Royal Society B.
- Study Links High Stress During Pregnancy To Children’s Asthma Risk
Massachusetts researchers say stress experienced by mothers during pregnancy increases the risk their children will develop asthma.
The researchers, with Brigham and Women’s Hospital and Harvard University in Boston, looked at the differences in immune function markers in umbilical cord blood between babies born to mothers in high-stress situations and those with lower stress.
They said in a statement that they found noticeable differences in patterns that could be linked to asthma later in the children’s lives.
The researchers said their study is the first to show that increased stress in urban environments could account for the high prevalence of asthma among African-American children.
Animal studies have already suggested that a mother’s stress during pregnancy can impact children’s immune system.
The study is published in the American Thoracic Society’s American Journal of Respiratory and Critical Care Medicine.
- Mother’s smoking increases daughter’s pancreatic cancer risk
A woman who smokes during pregnancy and motherhood appears to boost her daughter’s odds of developing pancreatic cancer, the deadly disease that will strike an estimated 21,420 women (and 21,050 men) this year.
Researchers from Harvard University and Imperial College London looked at pancreatic cancer rates in the Nurse’s Health Study, one of the nation’s oldest and largest studies of women and influences on their health. Although it’s long been known that tobacco use is associated with higher rates of pancreatic cancer, researchers wanted to explore the effects of secondhand smoke on a person’s risk of developing the disease. In the 24 years over which the women were followed, 384 of 86,673 women were diagnosed with cancer of the pancreas.
Pancreatic cancer is often called “the silent killer” because its symptoms are unlikely to be felt until the disease is in an advanced stage.
The study, published in the August issue of the journal Cancer Epidemiology, Biomarkers & Prevention, found that for women whose mothers smoked around them when they were young, rates of pancreatic cancer were significantly higher. A child whose father smoked or who was exposed in adulthood to a smoking family member or co-worker, was not significantly more likely to develop the disease.
Less clear is whether a mother with a smoking habit passes on to her daughter a heightened biological propensity to develop pancreatic cancer or an increased likelihood of smoking. Female nurses who themselves never smoked cigarettes were only slightly more likely than those who did not develop pancreas cancer, even if their moms smoked. The difference was small enough that researchers said it could have been attributable to chance.
But researchers did not rule out the possibility that a fetus or a child’s exposure to secondhand smoke might set in motion some biological process that puts that female child at risk. That would put pancreatic cancer in the company of many other negative health consequences for a child exposed to her mother’s smoking habit, including low birthweight, greater incidence of asthma and other respiratory diseases, higher risk of Sudden Infant Death Syndrome.
- Obesity in Pregnancy Ups Risk of Heart Defect in Baby
Obese pregnant women are at increased risk of having a baby with a congenital heart defect, a new study finds.
On average, obesity is associated with a 15 percent increased risk of having a baby with a heart defect. But the risk rises with the level of obesity. Compared to normal-weight women, the risk is 11 percent higher in moderately obese women and 33 percent higher in morbidly obese women.
In general, women who were overweight but not obese had no increased risk, said the researchers at the U.S. National Institute of Child Health and Human Development (NICHD) and the New York State Department of Health.
“The trend is unmistakable: the more obese a woman is, the more likely she is to have had a child with a heart defect,” study first author Dr. James L. Mills, of the NICHD’s Division of Epidemiology, Statistics and Prevention Research, said in a news release.
For this study, researchers compared the records of mothers of 7,392 children born with major heart defects and more than 56,000 mothers of infants born without birth defects. Because the study looked at the records of infants after they were born, it doesn’t conclusively prove that obese women who lose weight before becoming pregnant will reduce their risk of having a baby with a heart defect, the researchers noted.
However, “if a woman is obese, it makes sense for her to try to lose weight before becoming pregnant,” Mills said. “Not only will weight loss improve her own health and that of her infant, it is likely to have the added benefit of reducing the infant’s risk for heart defects.”
