Anemia caused by iron deficiency is one of the most common complications of pregnancy, with 9.3 percent of moms suffering from the disorder. But it's not just the mother who's affected by it. According to a study published in the Annals of Allergy, Asthma and Immunology, being anemic during pregnancy can lead to asthmatic babies.
The authors interviewed 597 mothers who had taken part in studies related to asthma in pregnancy and early childhood. Some of the mothers had no history of asthma, while others either had asthma themselves or had children who developed asthma early in childhood. Using interview data and medical records from the women's pregnancies, the authors compared anemia rates with childhood asthma rates and found that anemia during pregnancy led to a threefold increase in early-onset wheezing, a respiratory problem that develops at age 1 or 2 and leads to a 50 percent chance that a child will develop asthma by age 6.
In total, 12 percent of the mothers in the study were anemic during pregnancy, mostly due to iron deficiency (as opposed to other causes of anemia, such as vitamin B12 deficiency or the destruction of red blood cells, known as hemolytic anemia). Among their children, 22 percent were wheezing by age 1 and 17 percent were diagnosed with asthma by age 6. Mothers who had asthma themselves who were also anemic during pregnancy saw as much as a fourfold increase in the risk their children would develop wheezing or asthma.
It's not entirely clear what it is about iron-deficiency anemia that affects a kid's respiratory development, says Elizabeth Triche, PhD, assistant professor of epidemiology at Brown University and the study's lead author. "We know that oxygen is needed to develop the airways appropriately," she says, adding that adequate blood iron levels are needed to carry oxygen from the mother to the fetus. She cites a study from 2004 that found results similar to hers, in which mothers with low iron typically had children with wheezing levels.
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However, she says, "it could be that iron deficiency is just a marker for other nutritional deficits." Prior studies have found that maternal deficiencies of selenium, vitamin D, vitamin C, zinc, vitamin E, and folic acid can contribute to respiratory development problems in infants.
Protecting your baby's lungs during pregnancy starts with a healthy diet, and with a few other healthy behaviors:
• If you have asthma, take care of it. Whether you're iron deficient or not, having asthma during pregnancy can put you at risk for high blood pressure, premature birth, and birth defects, found a study published in the 2009 New England Journal of Medicine. So make sure you and your doctor have a good conversation about ways, both medical and nonmedical, to keep it under control for those nine months. Many pregnant women believe they have their asthma under control when they really don't, the 2009 study found.
• Ditch the fast food. That should be a no-brainer when you're pregnant—you don't want your baby being exposed to the pesticides and genetically modified ingredients found in junk. But eating a whole-foods diet can boost your iron levels, too. "Diets clearly have been changing negatively in respect to iron over the past 20 years," Triche says, pegging iron deficiency to diets that rely heavily on junk food. And, according to a study published last year, a healthy pregnancy diet also wards off allergies and eczema in children.
• Eat an iron-rich diet. "You should certainly always try to get as much iron as possible from whole foods," Triche says. If you need recipe ideas, search the Rodale Recipe Finder for Anemia Recipes. "But many women can't get enough from their diets," Triche adds, so ask your OB-GYN for suggestions about prenatal vitamins you can take. The supplements also help prevent deficiencies in some of the other vitamins and minerals that can affect your baby's lungs.
Published on: March 16, 2011
Updated on: June 6, 2012