So many women want to utilize the natural health benefits of essential oils during pregnancy but are worried with the extensive warnings out there. Many of those warnings come with a lot of claims and no evidence to back them up.
This is exactly how these topics scare and confuse people and make people miss out on the health benefits of natural options, just like we discussed in the first part of this series of breaking essential oil myths.
As I did in Part 1, this one is going to dig deep into the actual research and see which warnings have validity and which ones do not.
I have had six pregnancies and six babies and I am not content just taking anyone's word for anything when it comes to a precious unborn baby. I want to know straight up facts. So I went deep to see the actual research for myself. Here's what I found:
Extensive Lists of Oils to Avoid
Most articles on this topic will have an extensive list of specific essential oils to avoid during pregnancy. But they usually don't contain any research links or citations to substantiate each oil's presence on that list.
These lists are generated based off of studies or old texts that looked at a single, isolated constituent and used it in very high doses. Any plant oil containing a constituent that was linked to adverse effects is immediately associated with those results. This is our first problem. As Founder of the Pacific Institute of Aromatherapy Dr. Kurt Schnaubelt says:
So that's the first differentiation we need to make. Most essential oils labeled as dangerous during pregnancy for reasons such as causing miscarriage or birth defects are done so due to research on a single isolated constituent (and not necessarily even a natural version of that constituent) in high doses.
In completely pure and natural plant oils, constituents balance each other in amazing ways so the effects of a single isolated constituent is likely to be very different when balanced with other naturally-occurring constituents in a plant oil. This is important to keep in mind as we address these warnings and topics on essential oils.
Let's get into the specific oils. Some of those cited as dangerous that truly have evidence behind that information are essential oils that are not commonly available (and not even produced by the company I use) such as wormwood, pennyroyal, and Plectranthus. These are generally not commercially available because they can be harmful.
Aside from the many oils that are labeled as dangerous simply due to one of their constituents as we discussed, there are four main essential oils with that most sources agree to avoid in pregnancy: Sage (Spanish), Clary Sage, Wintergreen, and Fennel. So I dug into these oils specifically to see if those claims are substantiated. Here's what I found:
Spanish sage (Salvia lavandulifolia, not to be confused with the common herb from the mint family Salvia officinalis) is strongly cautioned during pregnancy in a way much different than essential oils and I personally agree on this one. A constituent in Sage, sabinyl acetate, does carry the highest risk in pregnancy and there is research to substantiate this claim.2
(For Young Living users, there is no Spanish Sage sold individually. It is in the following blends: Awaken, Harmony, Lady Sclareol, Oola Balance, Oola Friends, SclarEssence, and T-Away (Animal Scents).
Clary sage (Salvia sclarea) gets a bad rap due to claims that it can induce labor or uterine contractions.
But again, this is due to research on one of the isolated constituents used in high doses. On the many essential oils that are claimed to be uterine stimulants, here's the truth:
To err on the side of caution, clary sage can be avoided during pregnancy. But keep in mind that it can be very helpful for promoting labor progress in a full-term birth and should be utilized for this purpose whenever possible.
Fennel (Foeniculum vulgare) is listed as contraindicated during pregnancy due to its estrogenic properties. So I dug into this claim to see if it is substantiated or if it's another one labeled as dangerous because of an isolated constituent.
Sure enough, it's due to a single constituent. Fennel essential oil is high in E-anethole, and there have been mulitple studies that suggest E-anethole and pure fennel essential oil may have estrogenic effects.
There is a very old study that demonstrates very weak estrogen-like activity of E-anethole. There is another study that E-anethole can form polymers that act on estrogen receptors. Metabolites can weakly displace the E-anethole from receptor sites, and may cause an increase in uterine weight in immature rats. While fennel has been shown to have some weak estrogen-like activity, it did not lead to secretion of prolactin in vitro. This suggests that fennel (simply because it contains this isolated constituent that was studied) may have an impact on female fertility and on the estrogen receptor. However if it does so, it does so very weakly. And that doesn't factor in the balancing effect from essential oils with varying constituents in natural ratios.
There really is no substantial evidence to warrant complete avoidance of fennel essential oil during pregnancy.
Most warnings all agree that wintergreen essential oil should not be used during pregnancy. But why? I needed more than just a warning without any research links.
I found that the studies from which the warnings are based come from situations where A LOT of wintergreen or one of its constituents was used and often ingested.
I mean A LOT.
Like one where a 33-week old baby died in utero after the mother ingested THREE GRAMS of salicylate.1 Not wintergreen essential oil but salicylate which is one of the naturally-occurring constituents of wintergreen. But this was not wintergreen. It was synthetic isolated salicylate. So even though it wasn't even wintergreen, and even though it was a very large amount of this isolated constituent, wintergreen takes the heat for it.
But let's be reasonable here. No one's using that much and we're not talking about isolated constituents. Here's a summary of a study with reasonable information on the topic:
Keep in mind that the dangerous doses were literally many milliliters with each use so a few or even 10 drops a day is nowhere near that. And again, we are talking about research of the isolated constituents, not the constituents in their naturally-occurring ratios with other constituents in the whole plant oil.
So what's my take on this? I have no evidence to believe that judicious, moderate use of wintergreen essential oil (if it is truly pure and not chemically-synthesized constituents) occasionally in pregnancy is harmful at all.
Everyone is different. And every body is different. We each know our body better than anyone else. Do your own research and prayerfully decide what you feel is best for you. The most important thing is to be sure the essential oils you are using are what they say they are and not isolated synthetic constituents put together and called an essential oil.
Purity is of utmost importance.
Blessings of good health,
Sara Jo Poff
Natural Health Practitioner
1) Ellenhorn, M.J. and D.G. Barceloux. Medical Toxicology - Diagnosis and Treatment of Human Poisoning. New York, NY: Elsevier Science Publishing Co., Inc. 1988., p. 564
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