Maternal asthma tied to prematurity, lower weight

By Megan Rauscher

NEW YORK (Reuters Health) - Pregnant women with asthma are at heightened risk for delivering prematurely and of having a low-birthweight infant, according to a Canadian study discussed at the annual meeting of the American Academy of Allergy, Asthma and Immunology in Miami Beach, Florida.

The researchers investigated ties between maternal asthma and prematurity and low birthweight using the 1995 Manitoba birth data consisting of all 13,980 children born that year in the province.

The children were subdivided based on the length of pregnancy and weight at birth. The investigators then noted if the mothers had been diagnosed with asthma in the five years before delivery, Dr. Joel J. Liem from the University of Manitoba in Winnipeg told Reuters Health.

The prevalence of maternal asthma was 10.4 percent. In the children, 6.3 percent were born after fewer than 37 weeks of pregnancy and 4.9 percent weighed less than 2,500 g at birth.

The team found that an asthmatic mother was 2.77 times more likely, on average, to deliver at less than 28 weeks, and 3.04 times more likely to deliver at less than 32 weeks than a non-asthmatic mother.

Moreover, an asthmatic mother had a greater than threefold elevated risk of having a low-birthweight infant.

"Maternal asthma is a risk factor for the development and degree of prematurity and low birthweight in newborn babies," Liem said. "Physicians and other health care professionals need to assess present and past asthma -- even up to five years prior -- to properly assess risk for premature labour," he added.