Obesity, Passive Smoking Risk Factors for Infant Health


It is widely known that both obesity and maternal smoking pose many health risks to the developing fetus, including a greater chance of the child being obese in later life and taking up the smoking habit. Researchers from Cairo University in Egypt have found a much more serious condition in babies born to obese mothers exposed to tobacco smoke – a decrease in oxygen supply to the fetus.

Pediatrician Abd El Baky of the National Research Centre in Cairo divided 65 mothers into three groups. Group I, 29 infants, were born to obese mothers. Group II, 21 babies, were born to mothers exposed to tobacco smoke during their pregnancy. Group III, 15 babies, served as controls. The team measured levels of nucleated red blood cells (NRBCs) in the umbilical cord of the newborns. Raised levels are indicative of a degraded oxygen supply to the baby during the pregnancy.

Both babies born to mothers in Groups I and II had higher NRBC counts than those in Group III.

Exposure to maternal smoking seems obvious enough as a danger to the newborn, but mother’s exposure to second-hand smoke, or passive smoke, was also found to be significant. Inhalation from any source affects the amount of oxygen delivered to the unborn child and can alter the immune system at a critical stage of fetal development.


Recent studies have found that both maternal smoking and exposure to second-hand smoke after birth were both risk factors for the child to develop asthma and allergies. Children of mothers who smoke have at least double the risk of having asthma before the age of four (a separate study found six times the risk). Four-year olds exposed to passive smoke had elevated levels of IgE antibodies, a sign of allergic reaction, against one or more allergens.

Maternal obesity at conception affects gestational metabolic factors and the fetal growth and development. Most critically, according to the study authors, is fetal development during the last half of pregnancy that depends upon oxygen and nutrient supply. Obesity also raises the risk of other developmental abnormalities, such as neural tube defects.

"We recommended that every effort to control maternal obesity and prevent exposure to tobacco smoke be made," the team says, they insist that "smoking regulations in the workplace and at home should be enforced strictly for the well-being of our infants."

Sources for this article include:
"Effect of maternal obesity and passive smoking on neonatal nucleated red blood cells" in Int. J. Food Safety, Nutrition and Public Health, 2010, 3, 57-63

Thesis: 'Parental smoking, wheezing and sensitisation in early childhood', Eva Lannerö Institute of Environmental Medicine (IMM), Karolinska Institutet http://diss.kib.ki.se/2008/978-91-7357-452-5/

Apte S, et al "Childhood persistent asthma after in utero tobacco exposure in Mexican, Puerto Rican, and African Americans" J Allergy Clin Immunol 2010; 125: AB57.