It’s estimated that about one in 12 people have asthma, resulting in impaired breathing that’s sometimes life-threatening.
Now it appears that pregnant women need to be especially cautious around people who are sniffing and sneezing.
Researchers led by a team from University Children’s Hospital in Munich followed 526 German children from birth to five years of age. The scientists interviewed parents during the pregnancy, then assessed the child’s health every year after birth over the five-year period, also taking measurements of potential allergens in each child’s home.
The results showed that maternal illnesses during a pregnancy, such as repeated common colds, meant that a child’s risk for an asthma diagnosis by age five was about 2.3 times higher.
“We know that allergy and asthma can develop in the womb since genetics play a factor in both diseases,” allergist Michael Foggs, president of the American College of Allergy, Asthma and Immunology, said in a statement. “But this study sheds light about how a mother’s environment during pregnancy can begin affecting the child before birth.”
Other studies have shown that having two parents with allergies means a child has a 75 percent chance of developing allergies; even if only one parent has allergies, a child’s risk is still at 30 percent to 40 percent. If neither parent has allergy, the chance is only 10 to 15 percent.
In the new study, the German researchers found that being exposed to common allergens early in life had consequences later on – but not all allergens are created equal. For example, cat ownership by itself did not seem to affect a child’s risk for asthma or impaired breathing.
“Children who had early exposure to allergens, such as house dust and pet hair, had increased odds of becoming sensitized [to the allergens] by age five,”
said Mitch Grayson, deputy editor of Annals of Allergy, Asthma and Immunology. But “when dust mites from the mother and child’s mattresses were examined, children with high dust mite exposure yet low bacteria exposure were more likely to be allergic to dust mites than those with low mite exposure and high bacteria contact.”