Uncontrolled asthma during the first trimester of pregnancy greatly increases the risk of birth defects in babies, according to new research to be published in the June issue of the Journal of Allergy and Clinical Immunology.

Canadian researchers Lucie Blais, PhD, and Amelie Forget, MSc, concluded that women who had an asthma flare-up in the first three months of pregnancy were 48 percent more likely to have a baby with at least one congenital defect than asthmatic mothers who did not have a flare-up in the first trimester.

The rate of birth defects among the children of mothers who experienced a flare-up was 12.8 percent, versus a rate of 8.9 percent for mothers with better-controlled asthma, according to study data.

In total, researchers analyzed more than 4,300 pregnancies through health care and pharmacy records.

The findings underscore the need to keep asthma well-managed throughout pregnancy, but especially in the first trimester – a crucial period for fetal development.

The American Academy of Allergy, Asthma & Immunology (AAAAI) recommends all pregnant women with a history of asthma consult with an allergist/immunologist to ensure the asthma is well-controlled.

When a pregnant woman has trouble breathing, as during an asthma attack, both mother and fetus can experience a drop in the level of oxygen in their blood. A fetus needs a consistent supply of blood for normal growth and survival.

Pregnant women, like all asthma patients, should avoid common asthma triggers such as house dust mites, animal dander and smoke, according to the AAAAI.

An allergist/immunologist can prescribe safe and effective medications for controlling asthma during pregnancy.

To learn more about asthma and pregnancy or to find an allergist/immunologist in your area, visit aaaai.org.

The Journal of Allergy and Clinical Immunology (JACI) is the official scientific journal of the AAAAI.

Submitted by Kimberly Jahnke of The American Academy of Allergy, Asthma & Immunology (AAAAI) as a public service.