Mothers who smoke during their pregnancy can improve their unborn baby's health and lung function by taking supplemental vitamin C pills, according to a recent study Counsel and Heal reported.

During pregnancy, mothers are discouraged from smoking to reduce the risk of health complications for the fetus. Previous studies have found that smoking during pregnancy can negatively impact lung development, "which increases the risk of future respiratory problems for the newborn," Counsel and Heal reported.

More than 50 percent of smokers who become pregnant continue to smoke, corresponding to 12 percent of all pregnancies

"Although smoking cessation is the foremost goal, most pregnant smokers continue to smoke, supporting the need for a pharmacologic intervention," the authors write in their study.

For the study, researchers randomly assigned pregnant smokers to receive vitamin C or placebo. One hundred fifty-nine newborns of pregnant smokers (76 vitamin C treated and 83 placebo treated) and 76 newborns (reference group) of pregnant nonsmokers were studied with newborn pulmonary function test (performed within 72 hours of age).

The researchers found that newborns of women randomized to vitamin C, compared with those randomized to placebo, had improved measures of pulmonary function. Offspring of women randomized to vitamin C had significantly decreased wheezing through age 1 year. There were no significant differences in the 1-year pulmonary function test results between the vitamin C and placebo groups.

"This emphasizes the important opportunity of in-utero intervention. Individuals who begin life with decreased PFT measures may be at increased risk for chronic obstructive pulmonary disease," the authors wrote in the study.

Researchers concluded that vitamin C supplementation in pregnant smokers may be an inexpensive and simple approach to "decrease some of the effects of smoking in pregnancy on newborn pulmonary function and ultimately infant respiratory morbidities, but further study is required."

The findings were recently published in JAMA.