In every other aspect of my pregnancy, I'm trying to avoid any artificial substances as far as possible, on the basis that I can't be certain of the potential side-effects on a growing fetus (eg, I've eliminated alcohol, all caffeine, E-numbers, and have switched to 'natural' deodordant, shampoo, cleaning products, etc, etc ...
Ohh be careful there. Alcohol and caffeine are both natural products, so a "100% Natural Mouthwash" may contain as much, or more, alcohol as a regular mouth wash.
Of course N1H1 is totally natural. As is anthrax. Natural doesn't always mean good for you.