Originally posted on Nov 2009 on the
MIDIRS WEBSITE Nausea and vomiting in pregnancy (NVP) is an underrated and often disregarded condition which has immense significance for the mother and her family.
Indeed, it is not simply a condition which affects only the mother, but impacts also on her partner, her children, her job and her everyday life.
The term ‘morning sickness’ is a misnomer, because whilst many women have early morning nausea on waking, due to hypoglycaemia, many continue to suffer throughout the day and even into the night. Similarly, the traditional midwifery advice that symptoms will resolve spontaneously by the beginning of the second trimester can be discouraging, for many women feel unwell for the duration of the pregnancy, and others, whose condition may have improved in the mid-trimester, may experience a return to NVP towards term as the hormones change in preparation for labour.
Midwives should be able to differentiate clearly between physiological NVP (even when it is severe) and pathological hyperemesis gravidarum. Physiological nausea occurs in up to 85% of pregnant women (Jewell & Young 2003), with approximately half of these experiencing vomiting, but pathological hyperemesis occurs only in about 2.4% of the total (Power et al 2001), or between one and 20 cases per 1000 pregnancies (Kuscu & Koyunco 2002). Hyperemesis is defined as persistent vomiting causing weight loss of more than 5kg, with dehydration requiring fluid replacement, usually in hospital (Power et al 2007). However, undervaluing mothers’ subjective accounts of NVP may contribute to increased stress and unnecessary delays in instigating the appropriate treatment, particularly when the condition becomes pathological (Munch 2000). The effects of NVP are what the mother says they are, and the dismissive attitude of many GPs and some midwives is unhelpful and unkind.
NVP is largely considered to be ‘hormonal’, but this is an easy answer to a complicated question, because many different hormones are involved. Nausea has variously been attributed to oestrogen, progesterone, chorionic gonadotrophin, thyroid stimulating hormone and thyroxine, prostaglandins, testosterone and cortisol as well as other chemicals such as serotonin 5-HT, histamine and dopamine. Vomiting is triggered by changes in the brain, gastrointestinal tract and vestibular apparatus in the ear. NVP is exacerbated by tiredness, stress and anxiety, and appears to be worse in women with a history of muscusloskeletal problems, notably back, neck or jaw conditions (Tiran 2009). However, it is not the purpose of this paper to discuss the myriad causes and predisposing factors which contribute to NVP, and readers are referred to Tiran (2003) for a more comprehensive exploration of the subject.
Lifestyle advice
There are many suggestions which midwives can offer to women with mild to moderate NVP, although, often, women will try to cope alone until the symptoms have persisted for longer than they anticipated. The ubiquitous ‘tea and dry biscuit before getting up’ regime is not always appropriate, although those who feel more nauseous when they are hungry (as on waking) will gain some short term relief from eating. Unfortunately, biscuits are not the best means of satiating hunger, because the fast-release sugar is quickly metabolised and hypoglycaemia follows, leading to a vicious circle of eating – nausea – eating, and the risk of excessive weight gain. Slow-release carbohydrates are better, including bananas, porridge, jacket potatoes, wheatgrain toast, rice crackers etc. Women should not be made to feel guilty about eating a poor diet at this time, but should be encouraged to eat whatever foods are attractive to them, and which are not vomited back.
Nausea may be exacerbated by iron, so avoiding routine ingestion of iron-containing multivitamin supplements in early pregnancy may have some effect in reducing the severity of symptoms (Gill et al 2009). Additionally, the palate tends to be very sensitive and resulting stimulation of the gag reflex triggers retching and vomiting, so attempting to swallow large tablets (such as vitamin B) is ill-advised (Koren & Pairaideau 2006); a liquid preparation such as Floradix™ may be more palatable if a mother is known to be vitamin and mineral deficient. Conversely, some authorities advocate the use of vitamin B6 as a treatment for gestational sickness (Power et al 2007), although Masino & Kahle (2002) advise caution as there is some suggestion that large doses may affect neurological development which could be permanent after fetal exposure. For women who are able to eat relatively normally, consuming foods rich in vitamin B6, such as avocado, bananas, yeast extract, wheat bran, wheat germ, sardines, mackerel, beef, poultry, brown rice, cabbage and free range eggs may help.
Rest and sleep are important to reduce fatigue and it has been shown that many women spontaneously resort to ‘napping’ (O’Brien et al 1997), although occupational commitments or dealing with other children may preclude this as a long term strategy. Any means of alleviating stress should be advised, including taking time off work or adapting working practices where possible, such as working from home. Manageable exercise and obtaining fresh air should be encouraged if the NVP is not so severe that it confines the mother to bed, and relaxation and complementary therapies can be advised (see below). It is also necessary to ensure that partners and family members appreciate the nature of the problem. Some partners become over-solicitous and fear that the NVP will be harmful to the mother or baby, athough it appears to be nature’s way of protecting the materno-fetal unit (Brown et al 1997, Huxley 2000). However most men find it difficult to cope if the NVP lasts more than a few weeks, and diplomatic counselling may be needed to assist them in dealing with the situation.
Ginger
Ginger, in the form of capsules, syrup or a tea made from the root has been shown in numerous studies to be an effective antiemetic (Ozgoli et al 2009), reducing the number of vomiting episodes and comparing favourably with vitamin B6 supplements (Ensiyeh & Sakineh 2008) and other prescribed medications (Pongrojpaw et al 2007). Ginger appears to be almost universally known as a remedy for morning sickness and is readily advocated by midwives (personal communications), despite many having insufficient information to advise women accurately and safely. Ginger is also recommended by many obstetricians (Power et al 2007) although little advice appears to be given regarding dosages and there is scant acknowledgement of the pharmacological nature of ginger, despite wide variations in the proportions of the active components in many commercially available preparations (Schwertner et al 2006). It should be remembered that ginger is a herbal medicine which works pharmacologically, with side effects such as heartburn, and that it also has the potential to interact with drugs (Marcus & Snodgrass 2005). There is evidence to suggest that ginger has anticoagulant effects, especially if taken in excessive amounts or for prolonged periods of time, a factor which may preclude its use by women with haematological conditions, those on warfarin or other drugs with anticoagulant effects, and in those suffering threatened miscarriage (Thomson et al 2002, Borrelli et al 2005, Jiang et al 2005). Mothers and midwives mistakenly believe that ginger biscuits are acceptable but, although the large amount of sugar may bring temporary relief from a rise in serum glucose, any antiemetic effect is not due to the minimal amount of ginger in a biscuit. In addition, ginger is, in Chinese medicine terms, a ‘hot’ or ‘Yang’ remedy which, if taken by a woman who is already too ‘Yang’, will only serve to increase her symptoms (Tiran & Budd 2005).
Wristbands
Commercially produced wristbands, originally intended for travel sickness, are widely available and can be very effective. They work by stimulating an acupuncture point, the Pericardium (P6) or Neiguan point, on the inner aspect of the wrist, from where an acupuncture energy line (meridian) travels through the body to rebalance internal energies to and from the heart. Stimulation of the P6 point with acupuncture needles can also be undertaken by appropriately trained professionals. There have been numerous good calibre research studies on P6 stimulation and sickness of various aetiology, including NVP (Helmreich et al 2006, Streitberger et al 2006, Shin et al 2007, Can Gürkan & Arslan 2008). Siting of the wristband, with the stimulation button directly over the precise area for the P6 point, is important as incorrect positioning will make the bands ineffective, and is one of the reasons why use of P6 stimulation may be unsuccessful in some women. Stimulation of the P6 and other relevant points may also be undertaken by an acupuncturist, but mothers should be advised to find a qualified practitioner, preferably one who is experienced in treating pregnant women.
Vestibular stimulation
NVP is triggered, and can be exacerbated by, abnormal effects on the vestibular (balancing) mechanism in the ear (Black 2002). NVP is often worse for women prone to travel sickness, and normalisation of the balancing mechanism can be a simple means of reducing the severity of symptoms. A study of women with hyperemesis gravidarum indicated that electrical stimulation of the vestibular apparatus was effective in reducing nausea and excessive vomiting (Golaszewski et al 1995), and a contemporary commercial DVD (Morningwell™) is now available from the National Childbirth Trust. This uses inaudible pulsed frequencies overlaid with music, and must be used with personal headphones so that the pulsations rebound on the vestibular apparatus in the ears. The manufacturers claim this to be 90% successful in suppressing NVP, a fact which was borne out by a small study by a midwife in Hampshire (Mayo 2001).
Relaxation complementary therapies
Relaxation therapies can be helpful in cases where the NVP is worsened by stress and psychological factors, but midwives with little knowledge of complementary therapies should be cautious when advising women about these. Aromatherapy is not always acceptable because of the dramatic changes in the woman’s sense of smell which can occur, and because many essential oils are contraindicated in pregnancy (Tiran 2001). Reflexology can be helpful when administered by an experienced and well trained therapist, but it should be noted that most reflexology training courses discourage practitioners from treating women in the first trimester. On the other hand, reflex zone therapy, practised primarily by conventional healthcare professionals including midwives, nurses and physiotherapists, can be extremely effective in reducing the severity of symptoms, in some cases completely resolving the condition (Tiran 2009). Shiatsu, given by a practitioner who is trained to treat pregnant women, can also be beneficial, and massage may appeal to some women (Agren & Berg 2006). Psychological therapies such as hypnosis may also be of use (Simon & Schwartz 1999). Often, just listening to the mother and validating her symptoms can be a relief which enhances her coping mechanisms.
Other complementary therapies
Osteopathy and chiropractic, which are ‘professions supplementary to medicine’ and whose practitioners are statutorily regulated in the same way as midwives, are safe in pregnancy and will be effective for many women with NVP, but particularly those with a history of musculoskeletal problems. Homeopathic remedies can be useful for some, but it is important that the remedy is selected carefully in accordance with the individual mother’s precise symptoms. Although many homeopathic remedies are available over-the-counter, inappropriate administration can prolong the symptoms and may exacerbate the condition. Other herbal medicines can sometimes be beneficial, but mothers are best advised to consult a qualified and experienced practitioner, rather than self-administering remedies which may not be safe during pregnancy.
Conclusion
NVP is a common physiological condition of pregnancy, but one for which the incidence appears to be growing, perhaps due to stressed lifestyles, work commitments, delay in childbearing, environmental toxins and other factors. Whilst midwives may not always see women in the first trimester and be in a position to advise them in the early stages, they frequently come into contact with mothers in later pregnancy who are still suffering. Advice about lifestyle, dietary adaptation and simple self-administration of natural remedies may be sufficient to ease the severity of symptoms in many women, and midwives can also refer women to appropriately qualified complementary practitioners. This is, however, a specialist area of midwifery practice which deserves more attention in pre-registration education and subsequently in clinical practice.
Breaking news
Ginger use during pregnancy is being questioned due to a new report from the Finnish government. Finnish authorities are warning pregnant women not to consume ginger supplements, drinks, or teas. Ginger contains chemicals that are cytotoxic in vitro. The concern is that these chemicals MIGHT be harmful if consumed in large quantities. So far, no obvious problems have been seen in pregnant women taking ginger supplements in doses of about one gram daily. Advise women not to overdo it. More is not necessarily better. Also, consider recommending pyridoxine (vitamin B6) first for morning sickness. Vitamin B6 12.5 - 25 mg three or four times daily is safe and often effective for mild nausea.
References
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Tiran D (2009). Reflexology for pregnancy and childbirth: a definitive guide for healthcare professionals. Edinburgh: Elsevier Science.
Denise Tiran is Director of ‘Expectancy’, the leading provider of professional education on safety of complementary therapies in pregnancy and childbirth. She would be interested to hear from midwives who would like to consider training to become Expectancy registered ‘morning sickness’ consultants.
