Pulmonary function of babies born to women who smoked during pregnancy was significantly improved if the women took vitamin C, U.S. researchers say.

Dr. Cindy McEvoy, associate professor of pediatrics at Oregon Health & Science University Doernbecher Children's Hospital, said the study involved newborns of 159 smokers and randomized them to daily vitamin C -- 500 milligrams or placebo -- before 22 weeks gestation, with treatment continued through delivery. Seventy-six non-smoking pregnant women were studied.

The primary outcome of the study was the measurement of the newborn's lung function with a pulmonary function test at about 48 hours of life.

"Smoking during pregnancy is known to adversely affect the lung development of the developing baby," McEvoy said in a statement. "We found that daily use of vitamin C (500 mg/day) by smoking pregnant woman significantly improved pulmonary function tests administered to their offspring at about 48 hours postpartum."

The results will be presented at the American Thoracic Society International Conference in San Francisco.

(UPI)