Complementary Therapies for
Nausea and Vomiting in Pregnancy
Nausea and vomiting is one of the most troublesome symptoms experienced by women during pregnancy. In some women it commences only a few days after conception and it is commonly the first symptom that alerts women to a possible pregnancy. Unfortunately the problem, particularly the constant nausea, has a profound impact on the woman’s physical and mental wellbeing, her day-to-day life and her ability to care for the family and to continue working.
This chapter will consider how midwives, doulas and other maternity caregivers can help women to cope with nausea and vomiting in pregnancy (NVP). The use of self-help strategies such as ginger and acupressure wristbands is discussed, with a focus on safety. The benefits and effectiveness of other therapies to which women could be referred, for example acupuncture and osteopathy, are also discussed.
This chapter includes:
• NVP: a syndrome
• hyperemesis gravidarum
• conventional management of NVP
• peppermint and other herbal remedies
• sound therapy
• osteopathy and chiropractic
NVP is one of the earliest, commonest and most distressing conditions to affect expectant mothers. Significant symptoms occur in at least 50 per cent of women in early pregnancy but may occur to a lesser extent in up to 90 per cent (Lee and Saha 2011). Kramer et al. (2013) found the incidence to be 63.3 per cent in the first trimester and 45.5 per cent in later pregnancy, often exacerbated by social or occupational factors or psycho-emotional disturbances. Lacasse et al. (2009) showed that over 78 per cent of women in the first trimester and 40.1 per cent in the second trimester experienced NVP and associated problems such as hyper-salivation, with Caucasian women suffering – or at least reporting – greater symptoms than black and Asian women. Psychological issues prior to or during early pregnancy may increase the severity, and women who experience NVP may be at greater risk of postnatal depression or even post-traumatic stress disorder (Christodoulou-Smith et al. 2011). It is also known that severe NVP can adversely affect the fetus, including a higher than normal risk of neural tube defects, particularly when medication is required to manage the condition (Lu et al. 2015).
Commonly, and somewhat spuriously, termed “morning sickness” due to frequent hypoglycaemia-induced nausea on waking, many women experience symptoms all day, intermittently or continuously, with some even suffering during the night. Less than 2 per cent of women have morning-only symptoms. However, some women experience a return to the nausea and vomiting as they approach term, possibly in response to fluctuating hormone levels in preparation for labour. A few even continue vomiting into labour, with the condition miraculously and instantaneously resolving on the birth of the baby.
NVP is attributed to endocrine changes, primarily the high fluctuating levels of human chorionic gonadotrophin (hCG), oestrogens and progesterone. Thyroid hormones may be implicated (Buyukkayaci Duman, Ozcan and Bostanci 2015), as may impairment of the immune system (Fessler 2002) and alterations in serotonin, dopamine and histamine (Flake, Scalley and Bailey 2004). Effects on the vestibular apparatus in the ear are also thought to play a part, with many women reporting that any sensory stimulation, especially motion, provokes vomiting (Sinha et al. 2011). Some women are so debilitated that they are almost unable to lift their heads from the bed, and changes of position can either alleviate or increase symptoms.
The condition is often exacerbated by tiredness and anxiety, food cravings, aversions or preconceptional dietary deficiencies (Haugen et al. 2011) or by exposure to distinctive aromas. A personal or a family history of the condition, particularly in the woman’s mother or siblings, appears to predispose her to more severe symptoms including an increased risk of hyperemesis gravidarum (Annagür et al. 2014). Smoking may add to the problem in some (Sinha et al. 2011), although Kramer et al. (2013) and Källén, Lundberg and Aberg (2003) suggested it may confer a degree of protection from more severe symptoms. Increased body mass index may also contribute to the problem (Sinha et al. 2011).
NVP: a syndrome
NVP is a bio-psycho-social syndrome affecting not only the woman but the whole family.
Physiologically, many women report associated symptoms, including heartburn, diarrhoea or constipation, headaches, backache, hyper-salivation and more. The paternalistic approach of many doctors is often to dismiss these as normal and temporary, but this is not helpful when the woman is feeling wretched. As with pain, nausea is a subjective symptom and is as severe as the woman perceives it to be.
Socially, NVP may interfere with the woman’s ability to work and accounts for almost one third of sickness absence from work amongst pregnant women in the first trimester (Källén et al. 2003). Caring for other children may be difficult. Cooking meals may be almost impossible, particularly if nausea is worsened by exposure to meat, milk or other foods, a feature possibly related to the immunosuppression required to prevent fetal rejection (Fessler 2002). The partner may find it difficult to cope and the woman may worry about her lack of libido: it is known that men are most likely to have an extra-marital affair during the partner’s first pregnancy (Haltzman and Foy DiGeronimo 2008).
Emotionally, anxiety and fear, frustration and guilt increase cortisol levels; severe stress is more likely to lead to hyperemesis gravidarum (Leeners, Sauer and Rath 2000). As with cancer chemotherapy, experience of excessive NVP in previous pregnancies can trigger anticipatory nausea in the current pregnancy (Kamen et al. 2014). Personality also plays a part: some women may be full of self-pity or demanding constant attention, whilst others attempt to override their symptoms in order to continue their daily life with fortitude.
Some women are so overwhelmed by their condition that they yearn for an end to the pregnancy and it is estimated that 1000 pregnancies may be terminated annually as a result (Pregnancy Sickness Support 2013).
Hyperemesis gravidarum (HG) is defined as excessive vomiting (more than three daily episodes of expulsion of stomach contents) accompanied by weight loss of more than 3kg or 5 per cent of the pre-pregnancy weight, and/or dehydration (ACOG 2004), and affects around 0.3 to 2 per cent of the population (Goodwin 2008). It is, however, essential to differentiate a subjective claim of excessive NVP from the true pathological nature of HG. Celebrity pregnancies and media sensationalism of the condition have blurred women’s – and some professionals’ – understanding of HG and resulted in the popular notion that all NVP is HG. Indeed, over-medicalisation of the physiological syndrome can have adverse psycho-social effects and may impact on maternal-infant bonding (personal clinical experience).
In true clinical HG, the maximal number of daily vomiting episodes correlates closely with the maximal weight loss. Hospital admission is required only for those who have lost more than 3kg or 5 per cent of the booking weight and who require intravenous rehydration, although this may also be possible in the home setting. There may be an increased risk of intrauterine growth retardation if weight loss is excessive, since fetal growth patterns are disturbed by alterations in maternal metabolism. Other clinical signs and maternal symptoms of HG may include sunken eyes, dry mouth, ketotic, offensive-smelling breath, reduced skin elasticity and, in very severe circumstances, bradycardia, hypotension and oliguria with dark urine containing ketones, bile, sugars and protein, with a high specific gravity. The mother may exhibit signs of anaemia, alterations in vitamin B12, folic acid and vitamin C levels and disturbance in the electrolyte balance, with hyponatraemia, hypochloraemia, hypokalaemia, low urea levels and a raised haematocrit. Liver function tests may show abnormalities, and abnormal thyroid function (normally thyroxine deficiency) may be revealed.
It is vital to validate the woman’s experience as being significant to the progress of her pregnancy and her ability to cope with the demands of becoming a mother. Although vomiting can be measured in terms of its effect on weight, hydration and ketosis, symptomatic nausea is more difficult to assess. There are various validated tools to assess NVP, including the Rhodes Index of Nausea, Vomiting and Retching (Rhodes and McDaniel 1999), the McGill Nausea Questionnaire (Lacroix, Eason and Melzack 2000), the Pregnancy-Unique Quantification of Emesis and nausea (PUQE) system (Ebrahimi et al. 2009) and the Health-related Quality Of Life for nausea and vomiting in pregnancy (NVP-QOL). These can be helpful in excluding physio-pathological aspects of HG (Dochez et al. 2016), but most fail adequately to address maternal perceptions of the syndrome. A simple Likert scale, using a measurement of one to ten, may assist in this process (Tiran 2004, p.11). It is the woman’s perception of severity and, after treatment, of any improvement, which is important to her overall wellbeing, together with a professional validation of her symptoms.
Assessing the woman for the possibility of a differential diagnosis is important when considering appropriate treatment. HG and coincidental medical conditions must be excluded and, if necessary, treated; it is easy to assume that any nausea and/or vomiting, especially in early pregnancy, is solely due to gestational reasons. On the other hand, obstetricians generally feel that excessive vomiting after 16 weeks gestation is less likely to be pregnancy related and may indicate more serious pathology, which should be investigated, but care must be taken not to dismiss ongoing physiological NVP.
Thyroid hormones may be affected by NVP or, conversely, the NVP may disturb thyroid hormone balance, either scenario potentially triggering gestational thyrotoxicosis (Buyukkayaci et al. 2015) or previously undiagnosed preconceptional thyroid disease. If severe NVP symptoms remain unresolved with anti-emetics, thyroxine levels may need to be assessed and, if deficient, thyroxine medication can be offered. Other conditions which may cause vomiting, usually in conjunction with other signs and symptoms, include gastroenteritis and gastrointestinal disease, hepatitis, pyelonephritis, hiatus hernia and reflux oesophagitis occurring as a feature of other pathology. Hypercalcaemia, acute fatty liver and benign intracranial hypertension are less common but equally significant problems. Helicobacter pylori has been implicated, although this theory is controversial and research is inconclusive (Golberg, Szilagyi and Graves 2007). Genetic incompatibility between the mother and fetus, or epigenetic factors such as the effects of substance misuse on the woman’s system, could increase symptoms or, indeed, raise new pathology. For example, pregnant women who are habitual cannabis users may develop apparently intractable NVP, but if accompanied by abdominal pain and the unusual classic feature of obsessive bathing or showering, it may indicate cannabinoid hyperemesis, which is treated by discontinuation of the drug (Alaniz et al. 2015).
Conventional management of NVP
Most women initially attempt to manage their symptoms themselves, only asking for professional help when the problem persists. Traditional advice has been to eat little and often to maintain blood sugar levels and to eat a dry biscuit or toast before rising to combat early-morning hypoglycaemia. Unfortunately, this is largely ineffective and depends on the precise nature of the woman’s symptoms. Various dietary recommendations are made, such as avoiding fatty, spicy or strong-smelling or flavoured foods and eating small protein-dominant meals. This traditional advice in the UK may however no longer be appropriate in today’s multicultural society, since experience suggests that women resort to their cultural “comfort foods” when nauseated. In reality, women need to experiment to find which foods suit them best and it is more important that they eat foods that are more likely to be retained, providing some calorific content, than that they try to eat foods considered to be most nutritious. Adding feelings of guilt about their poor diet to the physical and emotional distress already experienced as a result of this debilitating condition is unrealistic, inappropriate and unkind. Women should, however, be encouraged to maintain an adequate fluid intake, especially when vomiting frequently.
Rest and sleep are important to reduce the impact of fatigue and, if feasible, women may need to take time off work or be advised to adapt their work schedule, perhaps altering start times to avoid commuting in the rush hour, or working from home occasionally. A recognition that health professionals empathise and appreciate the impact of NVP will go a long way towards influencing the mother’s perception of her condition, even though the amount of nausea and the frequency of vomiting may be very little different from before.
Women consulting their midwives or doctors for more specific assistance will probably, although not exclusively, be at a stage where they have tried many of the self-help suggestions (see below) but feel that they cannot cope any longer. Vitally, the specific cause of the problem should attempt to be sought prior to treatment. It is not sufficient to dictate a general course of action because this will not be effective for all women. Doctors commonly prescribe medication such as antihistamines (e.g. cyclizine, promethazine), vitamin B6 (pyridoxine), sometimes in combination with antihistamines (e.g. diclectin), phenothiazines (e.g. prochlorperazine), steroids (e.g. prednisolone) or the relatively new ondansetron. These may be available in suppository form for those women who vomit after ingesting them or who are unable to swallow them. However, whilst these are usually effective in reducing the severity of vomiting, they are frequently reported by women as being ineffective at adequately reducing the unremitting nausea, a symptom which is often worse than the actual vomiting (Fejzo et al. 2013). Further, some women do not wish to take medication, although the evidence of any possible teratogenicity appears to be unfounded. Conversely, Fejzo et al. (2013) found that, in a group of previously hyperemetic women with poor antenatal and labour outcomes including gestational hypertension, at least 50 per cent had taken medication, most commonly antihistamines, leading them to suggest an urgent need to address the safety of antihistamines in pregnancy.
Admission to hospital should only be considered for women with true hyperemesis, and there is a move towards day case treatment in specially designated clinics (Dean and Marsden 2017), as recommended in the green-top guidelines from the Royal College of Obstetricians and Gynaecologists (2016). This strategy has been shown to be more acceptable to women with hyperemesis and may represent a considerable cost saving to the NHS. The use of complementary therapies for hyperemesis is inappropriate and unlikely to be effective in treating the problem until the dehydration has been addressed and the woman has returned to eating sufficiently to enable her to continue gaining weight. Once she has recovered from the severe effects of the hyperemesis she may well appreciate relaxation therapies to ease stress, enhance her wellbeing and facilitate her coping mechanism.
Dean and Marsden’s study (2017) indicated that women are generally dissatisfied with their treatment for NVP across the UK. This extends to the lack of information they receive, a despair that all health professionals seem to advocate the use of ginger (see below) irrespective of the severity of their condition, and the common dismissal and lack of validation of the problem by midwives and general practitioners. These factors persuade women to try various self-help and complementary and natural methods to deal with the sickness and its associated symptoms.
Women frequently experiment with different foods in an attempt to alleviate their NVP, either by increasing their consumption of certain foods thought to be helpful, or eliminating others that exacerbate the problem. Some nutrients are implicated in the development and severity of NVP, including deficiency of vitamin B6, zinc and magnesium. Nutrition advice for NVP is considered an element of conventional management, with women being given information about what foods they may find useful to alleviate symptoms. Unfortunately, an in-depth knowledge of nutrition as therapy is often lacking amongst midwives. However, whilst complementary medicine incorporates a group of therapies loosely defined as “nutritional therapies”, it is not the intention here to debate in any detail the more alternative or obscure modalities focusing on using foods as medicines. Maternity caregivers can be of help to women with NVP simply by developing a greater knowledge and understanding of how common foods can contribute to easing the symptoms.
Vitamin B6 (pyridoxine) is primarily needed to aid the metabolism of protein and amino acids; consumption of large amounts of protein requires increased levels of B6. The vitamin also helps in the metabolism of histamine, serotonin and hydroxytryptamine, and inadequate serum B6 contributes to mood disturbances. In pregnancy, B6 is needed for development of the embryonic neurological system, and contributes to brain development and cognitive function in the child. The metabolism of sugars and fatty acids and the formation of vitamin B3 from the amino acid tryptophan is also dependent on vitamin B6, as is the functioning of magnesium and zinc. The contraceptive Pill may interfere with the absorption of pyridoxine; women are usually advised to take a vitamin B supplement whilst taking the Pill. Those who become pregnant very shortly after discontinuing the Pill may embark on pregnancy with a clinical deficiency of the vitamin, potentially increasing the risks to the developing baby. Pregnancy, stress hormones (notably cortisol) and oestrogens also increase the risk of B6 deficiency due to an increase in tryptophan activity.
Zinc is also vital for a range of bodily processes, not least in reproduction. It is necessary for the transport of pyridoxine across the cell membranes, and inadequate levels may impair cellular immunity and other necessary functions during organogenesis. Zinc also aids in the metabolism of proteins, carbohydrates and phosphorus and facilitates the release of stored vitamin A. It is essential for the normal growth of the skin, hair and skeleton, a healthy immune system and repair of tissues throughout the body, including wound healing. Zinc requirements increase by up to 30 per cent in pregnancy to provide for development of the fetal central nervous system, and by up to 40 per cent in breastfeeding mothers. Calcium, vitamin B12, vitamin C, copper and other trace elements are needed to facilitate absorption of zinc from foods, which can be inhibited by excessive stress, consumption of tea, coffee and alcohol, processed grains and phytates found in bran and some cereals. Zinc absorption is also reduced by concomitant use of certain medications including the contraceptive Pill and iron tablets.
Magnesium metabolism is closely linked with that of calcium and phosphorus. Magnesium is essential for various metabolic processes including the distribution of sodium potassium and calcium across cell membranes, as well as vitamin B1 and B6 metabolism. There is a fair body of evidence on the use of magnesium, particularly in conjunction with vitamin D, to prevent pre-eclampsia, but there appear to have been few studies, particularly in recent years, on supplementation with magnesium to treat NVP.
Harker, Montgomery and Fahey (2004) argue that it is not appropriate to treat all pregnant women experiencing NVP with a single nutritional supplement (most commonly vitamin B6) and that individual assessment is required in order to determine precisely the nutrients in which they are deficient. Despite this, many general practitioners and obstetricians persist in routinely advocating vitamin B6 for women with NVP who are presumed to be deficient. Indeed, Wibowo et al. (2012) found that there was little statistically significant difference in NVP scores in women who took pyridoxine compared to a control group. Many studies compare vitamin B6 to ginger (see below) or to a prescribed anti-emetic or a placebo. These studies are generally taken from the perspective that vitamin B6 is a standard – and apparently successful – treatment; thus the conclusions usually promote the success of ginger as being at least as effective as pyridoxine, rather than as an investigation of the success of pyridoxine (Firouzbakht et al. 2014; Sharifzadeh et al. 2017).
Rather than taking commercially produced supplementation to replace vitamin B6, zinc, magnesium and other nutrients, it is far preferable if the woman is able to eat foods that contain these elements. However, it must be remembered that many women are unable to eat when nauseated, or unable to keep food from being regurgitated from the stomach, so empathy and diplomacy must be employed when advising women about dietary means of reducing their symptoms. Table 4.1 summarises some of the foods that contain the various elements discussed here.
A recent trial comparing vitamin B6 with the consumption of quince fruit (Cydonia oblongata) which is high in vitamin C suggested that quince may be more effective than pyridoxine in reducing NVP (Jafari-Dehkordi et al. 2017). In this study women were encouraged to eat the fruit. This is interesting since the purported therapeutic actions of quince, namely that it is pharmacologically antioxidant, antibacterial, antifungal, anti-inflammatory, hepatoprotective and antidepressant, relate to chemical constituents in the seeds which are usually discarded. One of the main active components in quince is mucilage, a soft fibre which can impair the absorption of oral medications, so women should be advised not to eat quince if they are taking prescribed anti-emetics.
Table 4.1 Foods containing nutritional elements that may ease nausea and vomiting
• egg yolk
• fish, especially tuna
• green leafy vegetables
• meat, especially poultry breast, beef
• nuts, especially pistachio
• pinto beans
• potatoes, sweet potatoes
• wholegrain cereals
• beans: green, lima
• egg yolk
• green peas
• herbs and spices: ginger, garlic, parsley
• meat, pork chops, beef
• milk, raw
• nuts: brazils, hazelnuts, walnuts, almonds
• oats, rye
• wholemeal bread
• green leafy vegetables
• soya beans
• tap water (hard water)
• whole grains
Ginger is one of the most popular self-help strategies used by women with NVP. However, the common practice in the UK of eating ginger biscuits is largely ineffective as there is insufficient ginger in commercially produced biscuits to have a therapeutic effect, although some temporary relief may be obtained, most probably due to the carbohydrate content alleviating hypoglycaemia. Unfortunately, this is usually followed by a reactionary slump in blood sugar, causing a resurgence of symptoms. Crystallised ginger may also work in the short term, as may ginger beer or ale. Traditionally brewed ginger beer may contain as much as 11 per cent alcohol and there is a high sugar content in most commercially produced brands, provoking a reactionary effect similar to that with ginger biscuits. More significantly, artificial sweeteners, such as Aspartame™, are used in some types of ginger beer, which can be potentially detrimental to the fetus (Portela, Azoubel and Batigália 2007). One Iranian study claimed successful treatment of pregnancy sickness with ginger biscuits (Basirat et al. 2009). However, the biscuits used in this study were specially formulated to contain a therapeutic dose of ginger and the study should not be interpreted as evidence that commercially produced ginger biscuits are effective at resolving symptoms.
Ginger, when taken in therapeutic doses, acts pharmacologically and should therefore be used with the same caution as applied to drugs. Ginger root is a common – and powerful – medicinal agent used in traditional systems of healthcare in many eastern cultures such as Chinese, Korean and Indian Ayurvedic medicine. It is important to use the correct species of ginger root for therapeutic use, namely Zingiber officinale, the common type offered for culinary use in most western markets and shops. Thai ginger (Alpinia galangal, technically a form of galangal), wild ginger (Asarum), wall ginger (Alpinia) and particularly green ginger (Artemisia absinthium) contain different chemical constituents which may be unsafe in pregnancy.
The balance of therapeutic chemicals varies according to whether the ginger is fresh, semi-dried or fully dried. It is best ingested as a tea made from grated fresh root ginger steeped in boiling water, to be sipped throughout the day. Chewing and then swallowing raw ginger root is not appropriate as poor mastication may lead to intestinal obstruction. The anti-emetic action of ginger is not yet fully understood but may be due to gingerols or shogaol, the dehydrated products of gingerols, and zingiberene, which antagonise serotonin (5-HT) and suppress vasopressin, reducing gastric activity (Lete and Allué 2016). The balance of gingerols to shogaols differs according to whether the remedy is made from fresh or dried ginger, and gingerols are known to be chemically unstable in certain circumstances (Giacosa et al. 2015). There is currently no consensus between countries on the maximum safe dose of ginger, but it is generally felt that doses should be no more than 1gm per day in divided doses of 250mg (Lete and Allué 2016).
There are many studies demonstrating that ginger, in therapeutic doses, is effective as an anti-emetic, for nausea and/or vomiting, in pregnancy, during chemotherapy, post-operatively and due to motion sickness (Lindblad and Koppula 2016; Panahi et al. 2012; Ryan et al. 2012; Thomson, Corbin and Leung 2014), although many advocate caution, as the safety of ginger has not yet been clarified. Viljoen et al. (2014) found that ginger appeared to reduce nausea but was not significantly effective in reducing episodes of vomiting. However, this increasing evidence for effectiveness has led NICE irresponsibly to recommend that advice about ginger can be offered as standard to women with NVP, despite the fact that it is not classified as a medicine and has therefore not been evaluated in terms of safety (NICE 2017a).
Unfortunately, the numerous studies that appear to demonstrate anti-emetic effectiveness vary considerably in terms of research methodology, making it difficult to interpret the results and draw firm conclusions, a fact which does not appear to have been acknowledged by the NICE working party. For example, some studies compare fresh or dried ginger or commercially prepared ginger capsules with vitamin B6 (Chittumma, Kaewkiattikun and Wiriyasiriwach 2007; Ensiyeh and Sakineh 2009; Firouzbakht et al. 2014; Haji Seid Javadi, Salehi and Mashrabi 2013; Sripramote and Lekhyananda 2003). Others compare it with a placebo (Nanthakomon and Pongrojpaw 2006; Ozgoli, Goli and Simbar 2009) or to various anti-emetic prescription drugs such as metoclopramide or dimenhydrinate (Pongrojpaw, Somprasit and Chanthasenanont 2007). Saberi et al. (2013) further complicated the picture by using a combination of ginger and acupressure at the Pericardium 6 acupoint (see below). Some studies did not identify which species of ginger was used, although most used Zingiber officinale. There is also inconsistency in the dosages, the form of ginger used (fresh or dried root, syrup, etc.) and the frequency and duration of administration (Lete and Allué 2016).
Significantly, in virtually all studies, the precise cause of symptoms in different subjects has not been identified, a fact which can seriously skew success rates. For example, ginger with vitamin B6 may successfully treat women with NVP due to pyridoxine deficiency but may be ineffective for NVP related to other aetiology. Furthermore, the outcome measures of most studies focus on the effect of ginger in stopping or reducing vomiting, whereas nausea is significantly more distressing for most women, occasional vomiting often bringing temporary relief (personal communications with women).
However, ginger, like all herbal medicines, is a pharmacological agent containing a wide range of chemical constituents with specific therapeutic actions, as well as possible side effects when used inappropriately. Shawahna and Taha (2017) purport that the pharmacokinetics of conventional NVP medication can be adversely affected by gestational alterations in gastric motility, glomerular filtration and plasma volume and the absorption, distribution, metabolism and excretion of drugs. These physiological issues would also, of course, affect the metabolism of other pharmacologically active substances such as herbal remedies, including ginger, suggesting perhaps that ginger and prescribed medication for NVP should not be taken concurrently.
There is, for example, evidence of the considerable anticoagulant effects of many herbal remedies, including ginger (Abebe 2002; Shalansky et al. 2007; Spolarich and Andrews 2007; Ulbricht et al. 2007), although Jiang, Blair and McLachlan (2006) dispute this. As there is a moderate risk of bleeding, women on anticoagulants, anti-platelet drugs, non-steroidal anti-inflammatories such as aspirin, or other drugs or herbs with an impact on blood clotting should avoid ginger, and all other herbal remedies with a similar action. Prolonged use may interfere with clotting factors; thus ginger is contraindicated in women with a history of miscarriage, vaginal bleeding or coagulation disorders. Women who regularly ingest therapeutically applicable doses of ginger for more than about three weeks should have blood taken to test for clotting factors, since prolonged duration may thin the blood. Marx et al. (2015) suggest there is some evidence for the action of ginger on platelet aggregation, although they accept that more research is needed to substantiate this.
Ginger can irritate the stomach and trigger oesophagitis; it is contraindicated if the woman is already suffering heartburn and should be discontinued if heartburn develops whilst taking it. Ginger may increase bile secretion and must not be taken by women with a history of gallstones (Yamahara et al. 1985), although Hu et al. (2011) dispute this. The gastric irritant effects also suggest that ginger should be avoided if there is a history of irritable bowel syndrome or duodenal ulcer. Swallowing masticated ginger root, as advocated in some cultures, is particularly inadvisable as the fibrous nature of the root may cause gastrointestinal blockage. Ginger lowers blood pressure and may interact with anti-hypertensive medication (Ghayur and Gilani 2005). Ginger may also, theoretically, cause cardiac arrhythmias and should therefore be avoided by anyone on calcium channel blockers such as nifederpine (Young et al. 2006). (NB Pregnant women with major cardiac disease should avoid all herbal remedies.)
The potential for ginger to interact with prescribed drugs is well documented, including anticoagulants as previously mentioned, barbiturates, benzodiazepines, beta blockers and herbs with similar actions, such as garlic, gingko biloba, ginseng, red clover and turmeric (Ulbricht et al. 2007). Further, since ginger is known to lower blood sugar, it should be avoided in women with diabetes mellitus which is controlled by medication or insulin (Mozaffari-Khosravi et al. 2014). Vaginal spotting has been observed in one study, and as ginger may inhibit thromboxane synthesis and platelet aggregation in vitro, concern was expressed by the researchers that continued administration at term could increase the risk of postpartum haemorrhage (Heitmann, Nordeng and Holst 2013), although, due to the changes in viscosity of the blood at this time, this is probably more a theoretical possibility than a real risk.
No substantive evidence could be found to indicate that ginger is teratogenic or mutagenic, although Finland and Denmark have taken steps warning pregnant women against antenatal use of commercial ginger-containing products. Furthermore, Finland specifically advises against ingestion of ginger and many other herbal remedies during pregnancy since it is not known which constituents could adversely affect the mother or fetus (Evira Finnish Food Safety Authority 2016). Conversely, more recent Norwegian research demonstrated no increased risk of fetal abnormalities when women ingested ginger when compared with a control group (Heitmann et al. 2013). A Korean study by Choi et al. (2015) found no greater incidence of fetal malformations in women who used dried ginger but there was a slight increase in stillbirths. However, the researchers noted that many women concomitantly used other herbal remedies, a factor that may have had a bearing on these results.
Ginger has been shown to be weakly cholinergic (stimulates acetylcholine) (Ghayur and Gilani 2005). This corresponds to the traditional Chinese medicine approach, in which ginger is considered a “hot” or “Yang” remedy. Its warming effects are therefore unhelpful in women whose internal energies are already too “hot” or “Yang”. This would include those who feel hot, are constantly thirsty, wanting cold drinks to cool them down, red-faced, perhaps “hot tempered” or irritable (see Chapter 2, Acupuncture).
In conclusion, it is beholden on healthcare professionals to dispel the myth that ginger is a universal anti-emetic remedy for NVP, because there are many women in whom it may be, at best, inappropriate, possibly exacerbating their NVP symptoms, or worse, unsafe according to their personal medical or obstetric history and current condition. A simple checklist can be used to aid prescription and eliminate contraindications (see Table 4.2). Whilst inadvertent use of ginger-containing foods and drinks are unlikely to cause harm in most women, it is necessary to remember that ginger is a pharmacological agent which should be prescribed individually. It is not merely a food supplement or a “natural” remedy, but a powerful tool which may reduce the severity of NVP symptoms in some women when used appropriately. Its risk-benefit profile has only recently started to come to light and there is a need for considerably more research into safety to balance the evidence we already have on its efficacy.
Table 4.2 Contraindications to use of ginger for nausea and vomiting in pregnancy
Medications which may interact with ginger
History of miscarriage/antepartum haemorrhage
Current vaginal bleeding
Elective surgery within next 2 weeks
Non-steroidal anti-inflammatories, e.g. aspirin
All herbs with anti-coagulant action
Cholagoguic (stimulates bile secretion)
Cholestasis of pregnancy
Gallstones, obstructive jaundice, acute liver disease
Ursodeoxycholic acid or other gallstone medication
Tendency to mid-trimester fainting and dizziness
Potentiates sedatives, hypnotics
Anti-epileptic drugs, benzodiazepines, barbiturates
Gestational diabetes, insulin-dependent or unstable
Diabetes mellitus, insulin-dependent or unstable
Insulin, oral anti-diabetic medication
Hot, sweating, thirsty for cold drinks, irritable
NB Try peppermint instead of ginger (unless cardiac disease)
Heartburn, flatulence, diarrhoea
Inflammatory bowel disease
Irritable bowel disease
Interference with iron absorption
Pre-existing iron deficiency anaemia
Inflammatory skin conditions
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Peppermint and other herbal remedies
Mint has long been heralded as an effective remedy for sickness. However, there are many different types of mint, some of which are not safe in pregnancy, and there are variable methods of administration. Peppermint (Mentha piperata), usually taken as a tea, is a popular alternative to ginger and is sometimes more appropriate for women, particularly for those who are more “yin” (see above and Chapter 2, Acupuncture). It has long been used in traditional medicine to treat a variety of gastrointestinal conditions. When administered orally as a tea or in capsule form, it can be effective for irritable bowel syndrome (Cappello et al. 2007) through an effect on gastric emptying (Inamori et al. 2007). Peppermint is also sometimes used for respiratory infections, headaches, neuralgia and toothache, for menorrhagia and dysmenorrhoea (Masoumi et al. 2016) and as a stimulant.
Peppermint essential oil is the only natural product included in the British National Formulary and is used in post-operative care for paralytic ileus and as an antispasmodic during procedures such as barium enema. There is also some suggestion that it may help with preventing cracked nipples in breastfeeding mothers (Sayyah Melli et al. 2007), although any oil should be washed from the skin of the breasts before the baby suckles. When used in combination with ginger essential oil, peppermint has been found to be effective for post-operative nausea (Hunt et al. 2013; Sites et al. 2014), including post-Caesarean section (Lane et al. 2012). However, ginger essential oil should be avoided in pregnancy as it is thought to have an effect on uterine activity (Calvert 2005).
Peppermint essential oil is a complex mixture of compounds, including 35 per cent to 70 per cent menthol, 15 per cent to 30 per cent menthone and 4 per cent to 14 per cent menthyl acetate, although pharmaceutical grade oil is typically standardised to contain at least 44 per cent menthol. Peppermint oil contains between 1 per cent and 4 per cent pugelone, which is neurologically and hepatically toxic, although various processes are used to reduce the pugelone content in commercial peppermint to below 1 per cent. When taken orally in large doses, peppermint oil can cause gastrointestinal symptoms including additional nausea and vomiting, as well as headache, allergic reactions and perianal irritation. Drinking the oil can cause mouth ulceration and gastric irritation. Animal research suggests that peppermint oil may adversely affect cytochrome P450s (Unger and Frank 2004), impacting on the metabolism of some drugs. Drinking large quantities of peppermint tea may affect iron absorption and interfere with drugs that are metabolised via the liver, including the anti-emetic ondansetron (Akdogan, Gultekin and Yontem 2004). It is also known to be a cardiac stimulant and to cause relaxation of smooth muscles in the bronchial tract (Balakrishnan 2015; Meamarbashi and Rajabi 2013), and hence also probably in the uterus, although this may be dose-dependent. Topically, strong percentages of the oil cause dermatitis.
A Middle Eastern randomised, double-blinded controlled trial of 60 women with NVP treated with peppermint oil obtained results that were not statistically significant (Pasha et al. 2012). Unusually, the treatment, conducted prior to night-time sleeping, consisted of placing a bowl of water containing four drops of peppermint oil on the floor by the beds of the women in the trial group, whilst the control group had bowls of water with four drops of normal saline added. This would not be the normal course of action for midwives providing aromatherapy to women, not least because sickness primarily commences in the mornings and the effects of the peppermint oil would not be sustained throughout the night as it would evaporate. In addition, women admitted to hospital are likely to be suffering more severe NVP requiring medication, and the placing of bowls of water on the floor in a ward area contravenes health and safety regulations. Furthermore, the type of mint used was not specified in this study, the oil being described only as “pure” peppermint which was specially prepared for the trial. This is of concern since certain types of mint are contraindicated in pregnancy, particularly in essential oil form as they contain high levels of constituents that should be avoided during organogenesis.
Roman chamomile (Anthemis nobilis) is one member of the Asteracea/Compositae family that is considered relatively safe to use during pregnancy, unlike German chamomile (Matricaria chamomilla) which may have oestrogenic effects (Zangeneh et al. 2010). Chamomile is a traditional remedy taken orally as a tea for nausea and other gastrointestinal problems and is used topically in essential oil form for wound healing and inflammation, including sore nipples. Chamomile tea is also known to aid sleep, although excessive doses may have the opposite effect. Chamomile has been used orally to stimulate uterine contractions in women with post-dates pregnancy and there is some suggestion that it may be sufficiently uterotonic to be abortifacient in the first trimester (Gholami et al. 2016). Chamomile tea may also be useful for lactation (Silva et al. 2017). Chamomile studies are variable and do not always identify the type of chamomile used; some involve the ingestion of teas, which are more dilute than prescribed tablets, or occasionally essential oils administered dermally. One paper reported the apparent effect of chamomile consumption in pregnancy on premature closure of the ductus arteriosus in the fetus. Alarmingly, this paper, published in the journal Ultrasound in Obstetrics and Gynecology, erroneously identified the tea consumed by the women as chamomile (from the Asteracea family), yet the authors’ discussion centred on Camellia sinensis, an evergreen shrub from the Theaceae family (Sridharan, Archer and Manning 2009). There are various reports on the possible adverse reaction of contact dermatitis from chamomile oil or even the tea, although this tends to be from Matricaria chamomilla rather than Roman chamomile (Anzai et al. 2015; Paulsen and Andersen 2012). At least one case of anaphylaxis from chamomile tea has been reported (Andres et al. 2009), and women (and caregivers) with sensitivity to members of the Compositae plant family, including chamomile and arnica, should avoid chamomile teas, essential oils, creams and other products (Paulsen, Chistensen and Andersen 2008).
Slippery elm bark
Slippery elm bark (Ulmus rubra), usually in lozenge form and more commonly used for constipation, is quoted on some websites as a suitable remedy for pregnancy sickness; indeed it may be prescribed by qualified medical herbalists. However, self-administration is not recommended because slippery elm has a reputation as an abortifacient, possibly due to certain chemicals in the outer bark. However, it is usually the inner bark that is used for medicinal purposes, and virtually no studies appear to have been undertaken on its safety in pregnancy.
Nettle (Urtica urens) tea is also advocated for sickness and constipation. Stinging nettle leaves contain high levels of iron, vitamins, potassium, calcium and carotene and may be advised by herbalists as a tonic during pregnancy. Herbal remedies are produced from the above-ground parts of the plant and from the root. Traditionally, the most common use for nettle is as a diuretic and for urinary problems such as nocturia, dysuria, frequency of micturition and retention of urine, as well as benign prostatic hyperplasia. It may also have a role to play in reducing blood pressure and heart rate (Qayyum et al. 2016). Taken to excess in tea form, nettle can cause diarrhoea, sweating and skin irritation, and a case of a woman who attempted to suck the leaves resulting in severe tongue oedema has been reported (Caliskaner, Karaayvaz and Ozturk 2004). There is risk of interaction with anti-diabetic and anti-hypertensive medication and with warfarin (Edgcumbe and McAuley 2008).
There is increasing interest in the use of aromatherapy as a treatment for pregnancy sickness. A recent Iranian randomised controlled trial of 100 women suggested that inhalation of lemon essential oil may ease NVP (Yavari Kia et al. 2014), although smelling fresh lemons may be a cheaper, easier and safer method of easing the nausea. The use of peppermint (Mentha piperata) oil has been discussed above. However, since there is some suggestion that NVP may be related to olfactory hyper-sensitivity (Cameron 2007; Erick 1995), aromatherapy may not be the most suitable treatment, although Cameron (2014) now disputes this olfactory link. However, the effect of odours on the severity of women’s experiences of NVP appears to be similar to that found in migraine patients, and is possibly linked to genetic factors (Heinrichs 2002). The close association between the senses of smell and taste also need to be taken into account, as women commonly crave or become averse to specific foods (Schachtman et al. 2016). In cases where a woman suffering NVP wishes to receive aromatherapy, percentages should be kept possibly to as low as 0.5 per cent, using a single essential oil. Light refreshing citrus oils can be pleasant for some women, including lemon (Citrus limon), lime (Citrus aurantium) or bergamot (Citrus bergamia).
No formal evidence for the use of homeopathic remedies for NVP could be found when searching the literature. A randomised double-blinded controlled study in France by Pérol et al. (2012) – in which breast cancer patients were given either standard anti-emetics, a homeopathic remedy combined with anti-emetics or a placebo – proved inconclusive as a means of treating chemotherapy-induced sickness, but no other trials on nausea and vomiting of any aetiology could be found. The main issue is that, in homeopathic terms, the symptom of sickness cannot exist on its own; rather the person experiences sickness as part of a whole symptom picture and therefore the woman must be treated holistically (see Chapter 2).
On the other hand, many women, especially those who are already familiar with the concept of homeopathy and homeopathic prescribing, like to use these remedies to alleviate nausea, vomiting and associated symptoms and there is considerable anecdotal clinical evidence that homeopathy can help. As with any other condition, homeopathic remedies must be prescribed according to the precise nature of the woman’s symptoms. No other therapy highlights so completely the complex nature of NVP; a focus on all symptoms experienced by the woman, however trivial or apparently inconsequential, will enable the practitioner to determine the most appropriate remedy.
There are several commonly used remedies that may be effective, but many more may be preferable if the characteristics of the woman’s condition dictate them. Only one remedy should be taken at a time and they should not be used concomitantly with aromatherapy essential oils or with certain strong drugs (see Chapter 2). Women who are familiar with self-prescribing of homeopathic remedies may be able to identify the most appropriate remedy for themselves. However, the complex nature of NVP suggests that women with no knowledge of this therapy should be encouraged to consult a qualified homeopath, because over-use of a remedy, or choosing one that is not appropriate, can trigger a reverse proving. Box 4.1 summarises a small selection of homeopathic remedies that may be of use for women with NVP.
Suggested homeopathic remedies for nausea and vomiting in pregnancy
• Ipecacuanha – constant nausea unrelieved by vomiting; profuse saliva, vomits food, bile frequently exacerbates nausea; dislikes smell of food or tobacco
• Nux vomica – constant nausea, often worse immediately after eating but relieved by vomiting; worst in morning; craves stimulants, e.g. coffee, tea, alcohol; “workaholic”
• Pulsatilla – nausea, worst in morning, unrelieved by vomiting; bitter taste in mouth; desires sour, fresh food; averse to fatty food, milk, meat, bread; changeable mood, easily moved to tears; fresh air, cold drinks improve symptoms, but exacerbated by hot drinks, stuffy room
• Sepia – intermittent nausea, with empty, dragging sensation in abdomen; craves vinegar, sour foods, sweets; averse to bread, fatty food, milk; exacerbated by exertion, smell and thought of food; worst before breakfast and between 1500 and 1700 hours
• Arsenicum – woman feels “deathly”; profuse frequent vomiting of food, bile, water, causing sweating; burning sensation in stomach; may crave coffee; symptoms are better with warmth; worse after cold food or drinks, particularly afternoons; dislikes smell of food
• Colchicum – most appropriate remedy when predominating feature is motion; particularly symptomatic in car, but in severe cases may be unable even to lift head from pillow
• Cocculus – most appropriate remedy when predominating feature is smell or sight of food, particularly eggs, fish
• Kreosotum – particularly valuable when there is excessive salivation