According to a new study, the more common colds and viral infections a woman has during pregnancy – and the more exposure she has to house dust and pet dander - the greater the chance her baby will develop allergies.
What exactly are you supposed to do with this information? Lock yourself away from life for nine months? Wrap yourself in (hypo-allergenic) cotton wool, Dyson the bedroom and don't go outside until your baby is born?
Anyway, back to the study. Published in the February issue of Annals of Allergy, Asthma and Immunology it found a mother's infections and bacterial exposure during pregnancy affect what happens in the womb, which potentially increases a baby's risk of developing allergy and asthma as they grow up.
Allergist Mitch Grayson, Annals deputy editor and fellow of the American College of Allergy, Asthma and Immunology (ACAAI), said: "In addition, these same children that had early exposure to allergens, such as house dust and pet dander, had increased odds of becoming sensitized by age five.
"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."
Researchers studied 513 pregnant women in Germany, and their 526 children. Questionnaires were completed during pregnancy, when the children were three and 12 months old, and every year up to five-years-old. Of the families, 61 percent had a parent with asthma, hay fever or atopic dermatitis.
The ACAAI says asthma and allergies can be hereditary. For example, if both of a child's parents have allergies, the child has a 75 percent chance of being allergic. If one of the parents is allergic, or if a close relative has allergies, the child has a 30 to 40 percent chance of having some form of allergy. If neither parent has allergies, the chance is only 10 to 15 percent.
Allergist Michael Foggs, MD, ACAAI president, said: "We know that allergy and asthma can develop in the womb since genetic play a factor in both disease.
"But this study sheds light about how a mother's environment during pregnancy can begin affecting the child before birth."
Asthma is the most common potentially serious medical condition to complicate pregnancy, according to the ACAAI.
In fact, asthma affects approximately 8 per cent of women in their childbearing years. When women with asthma become pregnant, one-third of the patients improve, one-third worsen and one-third remain unchanged.
For more information and a video about allergy and asthma during pregnancy, visit http://www.acaai.org/pregnancy.