Professional teeth-whitening may not be suitable for those with gum recession, tooth decay, dry mouth, poor oral hygiene, or people who wear dental devices, such as braces (via Livescience). It’s also not recommended for pregnant individuals. Because professional-whitening agents contain hydrogen peroxide, experts at A Family Dental Center explain that it can exacerbate gum inflammation — which can occur in response to changing hormone levels during pregnancy. Similarly, hydrogen peroxide exposure can also heighten tooth sensitivity. Tooth sensitivity is not uncommon during pregnancy, as morning sickness can flush the mouth with enamel-eroding acid. A teeth-whitening procedure or product may end up causing additional damage.
Finally, experts can’t say for sure whether or not teeth-whitening bleaching agents may be hazardous to the fetus. Therefore, due to the limited scientific evidence, the American Dental Association (ADA) suggests erring on the side of caution and holding off on any teeth-whitening treatments until after the baby has been born and is not breastfeeding.