This chapter includes discussion on:
• toxicity and side-effects of essential oils
• over-dose effects
• adverse skin reactions
• respiratory reactions
• essential oils and the eyes
• oral toxicity
• carcinogenicity and cytotoxicity
• teratogenicity, mutagenicity and fetotoxicity
• emmenagoguic and abortifacient essential oils
• essential oils which may affect uterine contractions
• effects on maternal blood pressure
• other medical and obstetric conditions
• essential oils and breastfeeding
• aromatherapy and the neonate
• effects of essential oils on midwives and other care providers
• contraindications and precautions to essential oil use in maternity care.
Introduction
Aromatherapy constitutes an element of herbal medicine. However, unlike herbal medicine which uses whole plants, in aromatherapy the essential oils are extracted and used in isolation from the other plant constituents (see Chapter 2). In clinical aromatherapy practice, these highly concentrated oils are blended together and administered with the aim of achieving a therapeutic effect in the client.
The issue of safety of aromatherapy in pregnancy and childbirth is of concern both to professionals and to expectant mothers. Unfortunately, any potential risks are not always recognised, because many people believe that
aromatherapy simply involves the use of fragrant oils and relaxing massage.
They do not realise that the oils contain chemicals which, once absorbed into the body, work in exactly the same way as pharmacological drugs. However, if a substance has the power to be beneficial, then it must, by inference, be potentially harmful if it is misused or abused – and it is this misuse which is so alarming in respect of pregnant women (and their babies).
Essential oils can be more hazardous, if used inappropriately, than some herbal remedies or teas, because the concentration of chemicals in the essential oils is so much more significant. Essential oils are also volatile and fat soluble, unlike water-soluble herbal remedies, and because they are lipophilic they can pass rapidly across membranes within the body, so any potential toxicity can be intensified beyond that seen with medicines produced from the whole plant (see Chapter 3 on pharmacokinetics).
There is growing concern amongst aromatherapy producers, practitioners and researchers in relation to the increased general use of aromatherapy, since the incidence of sensitivities and adverse reactions has increased, particularly contact dermatitis and severe respiratory effects. In addition, the increase in use of other chemical substances, including perfumes, cleaning materials, incense sticks and aromatic candles, has added to the problem, making people generally more sensitive to all fragrances, while over-use of common essential oils has led to inadvertent abuse, with new sensitivities developing in susceptible people, although it is difficult to attribute these effects to specific chemical constituents. Repeated exposure to foods to which individuals are allergic (e.g. fish) can eventually lead to an anaphylactic reaction, and continual over-use of essential oils could eventually produce similar consequences.
All essential oils are toxic at high doses, especially if taken orally. Safe practice results from a comprehensive understanding of the science of aromatherapy (see Chapter 3) and an appreciation of how to minimise any possible adverse effects. This means not only having an understanding of essential oils and their use in general clinical practice, but also an ability to apply the principles of aromatherapy to its practice within maternity care. However, identification of precisely which essential oils are safe to use for childbearing women is still very much open to question. There is no definitive evidence that aromatherapy – or the individual essential oils – is safe during pregnancy. We make an assumption about relative safety, based on the absence of any real data and the fact that thousands of women have used aromatherapy oils prior to and during pregnancy without any apparent adverse effects – or at least without any formal reporting of adverse effects.
Unlike drug preparation, there is no requirement to prove ‘beyond reasonable doubt’ that an essential oil is safe before it is made available to the market,
partly because essential oils, unlike herbal remedies, are viewed as ‘cosmetics’.
In any case, it would be impossible to obtain ethical committee approval to conduct formal randomised controlled trials on the safety of essential oils in pregnancy. This then poses the ‘chicken and egg’ dilemma of whether or not specific essential oils, or the general practice of aromatherapy, should be investigated to demonstrate its effectiveness or whether we need evidence of safety in the first instance. There would be no point in having evidence of one without the other, since essential oils may be effective but then found to be unsafe, or vice versa. (See Chapter 3 for further discussion on aromatherapy research.)
Practitioners and expectant mothers attempting to elicit information about the safety of essential oils in pregnancy and birth will find a plethora of conflicting and confusing advice, particularly in books or on Internet sites aimed at the general public, which frequently contain misleading and sometimes potentially dangerous information. Aromatherapy textbooks, professional aromatherapy organisations and insurance companies providing practitioner indemnity cover usually err on the side of caution when considering pregnant clients, without any real foundation or supporting evidence. This is, perhaps, more to do with protecting the practitioners and their relevant organisations from the threat of claims against them for alleged obstetric negligence than about any firm understanding of how essential oils and aromatherapy can be applied to pregnancy and childbirth. Also, professional regulations and insurance criteria are devised for practitioners who are not midwives and who may, without further training, have a lay person’s anxiety about working with pregnant clients. Further, even where there appears to be some evidence either supporting or refuting the safety of aromatherapy/essential oils in pregnancy, there may be other studies with conflicting results – and this can be confusing to all concerned.
It is wise, however, to set the issue of safety in context. We must remember that aromatic oils have been used for thousands of years by millions of people, many of whom will have been pregnant or breastfeeding.
In the Western world we are exposed to essential oils every day of our lives, in perfumes, bath products, cosmetics, food flavourings, incense sticks, aromatic candles and other commercially produced substances. Conversely, the ready availability of essential oils in high street health stores or via the Internet, and the popular belief that aromatherapy is ‘just’ aromatic oils and massage, coupled with the origins of UK aromatherapy in the beauty therapy business, means that the issue of safety appears to have been dismissed by many consumers. This extends to ill-informed healthcare professionals whose use is often based on the same misconceptions as those of their clients
and who fail to acknowledge the professional boundaries within which they should practise. (See Chapter 5 for more on professional accountability.)
Practitioners using aromatherapy for pregnant and labouring women must be aware of those essential oils which are contraindicated in general and those which should be avoided specifically during the preconception and antenatal periods, labour and the puerperium. They must also understand the reasons for these contraindications and precautions in order to justify their practice.