It’s hard to believe the practice of aromatherapy could be harmful to a pregnant client, but in fact some essential oils — called “emmenagogues” — are known to induce menstruation or other types of bleeding. Oils in this category include chamomile, cinnamon, fennel, ginger, jasmine, juniper, myrrh, peppermint, rose, sage, eucalyptus, and rosemary, any of which may be used in products for manicure and pedicure services. It is unlikely that the amount of exposure a woman encounters during a salon service would have an affect on her and the baby, but for liability and safety reasons, emmenagogues should be avoided, especially during the first trimester. To be perfectly safe, you might want to avoid these oils during the entire pregnancy.