Cough Suppressants and Pregnancy 

A new study negates findings of early animal studies that cough suppressants are harmful to women during their first trimester of pregnancy. Researchers from the University of Toronto report in this month's Chest, that the active ingredient is safe for pregnant women. 

This is the first study to specifically look at the effect of dextromethorphan (DM) in pregnant women. An earlier study in baby chickens indicated there might be risks of malformation to the unborn infant. Now, in a study of 172 births, there appears to be little or no risk associated with the ingredient. 

All women in the study group took DM during their pregnancy. Their outcomes were compared to those of women who did not use DM for upper respiratory infections. Of the women on the cough suppressant, there were three major malformations (2.8 percent) and 10 minor malformations. The average birth weight was 7.4 pounds. In the control group, there were 5 major malformations (2.8 percent) and 8 minor ones. The average birth weight in this group was 7.5 pounds. 

Researchers say these rates of malformation were considered comparable and showed no specific patterns. They also found no indication of neural tube defect, a problem discovered in the animal study. These are problems of the brain and spinal cord. While they suggest there may be a transfer of DM across the placenta, it does not appear to be enough to cause harm.