Not getting enough dietary iron is a big enough problem for fully grown adults, but during pregnancy a developing fetus can be particularly vulnerable to anemia. Herbal supplements and other nutritional health supplements may be able to help.

Babies who were exposed to iron deficiency in utero are more likely to be underweight than those who aren’t, the Centers for Disease Control and Prevention (CDC) says – to which a new study adds the risk of asthma.

Research published in the journal Annals of Allergy, Asthma and Immunology has determined that expecting mothers who are iron-deficient have a 22 percent chance of having a child with asthma.

That is roughly twice the lifetime rate of asthma estimated by the American Academy of Allergy Asthma and Immunology. The organization states that more than 34 million U.S. citizens will be diagnosed with the respiratory disorder in their lifetimes.

This figure was derived by examining the medical records of 600 families that were involved in the Asthma in Pregnancy Study. The study’s authors noted that this could be a widespread issue, given that up to 9 percent of the U.S. population has some level of anemia.

Taking a daily iron supplement may prevent the development of a deficiency, while contributing good muscular and respiratory health.