Pregnant and nursing women are advised not to use Essential Oils without the medical advice of a physician, as they can have effects on certain hormone secretions, and it is unclear whether these effects are transferable to babies at these stages of development. Some Essentials Oils can also potentially encourage bleeding. Always consult your physician or a reputable Aromatherapist before using any Essential Oil. Some oils to refrain from using throughout pregnancy include Ajowan, Basil, Camphor, Cedarwood, Chamomile, Clary Sage, Cypress, Fennel, Hyssop, Juniper Berry, Marjoram, Rose Geranium, Rosemary, and Thyme, to name a few.