We used to think that everything plant-based or natural was automatically safe. But that's not true for many things, including essential oils.
What problems can come from the use of essential oils?
Some terpenes (the molecules that give the oils their fragrance) can penetrate the skin [1], meaning they enter your body and bloodstream. No research has been done to prove if these terpenes cross the placental barrier; much remains unknown, but you should be especially wary of using essential oils during the first trimester when the baby’s organs are developing.
If essential oils cross the placenta, how will they harm the baby?
This question has not been studied sufficiently, mainly because experiments on pregnant women are ethically unacceptable. However, in long-term observations, there have been cases of toxic reactions, miscarriages, and abnormalities in the child's development, among women who used essential oils and essences during pregnancy [2, 3].
What are the safest and most harmful oils?
There’s no clear answer, but here’s what we know.
Citronellol is very effective in penetrating the skin barrier [1]. Therefore, it should not be applied to the skin during pregnancy. Citronellol is found in the following oils:
geranium
rose
citronella
On the other hand, coniferous oils are considered harmless, as the pinene they contain can hardly penetrate the skin [1]. Another ester they contain, linalyl acetate, is also inefficient in penetrating the skin barrier, so when mixed into a cream or lotion and not used in their pure form they won’t penetrate the skin[1]. That means the following oils are considered safe for pregnant women:
lavender
bergamot
eucalyptus — recommended by the Centers for Disease Control and Prevention (CDC) as a safe insect repellent [4].
In the case of lavender, it has been proven to have mild sedative and pain-relieving properties during the initial stage of labor [5].
