for Post-Dates Pregnancy
Many women are anxious to avoid medical induction of labour simply because they are “overdue” but feel pressurised by defensive obstetric practices influenced by a professional desire to prevent late intrauterine deaths and to avoid litigation. There is considerable social pressure on women to give birth as close to their estimated due date as possible, and many women become so desperate to expedite labour that they try every strategy they know to trigger uterine contractions. Unfortunately, these attempts to initiate labour, sometimes even before term, coupled with women’s lack of understanding that any intervention may cause a “cascade of intervention”, can lead to adverse effects on the mother, fetus or the physiological progress of labour. Conversely, there is an increasing interest amongst midwives to assist women in avoiding medical induction of labour and many are now investigating the use of complementary therapies for “natural induction”.
This chapter explores the vast range of self-help and natural means of triggering contractions, focusing on the evidence for effectiveness and safety. It also debates the growing trend for midwives to establish post-dates pregnancy clinics using various complementary therapies.
• women’s desire to self-initiate labour
• self-help methods to aid cervical ripening and dilatation
• self-administration of pharmacologically active plant remedies
• consumption of fruit to aid labour onset
• homeopathic remedies
• acupuncture and acupressure
• professional use of complementary therapies and natural remedies for women with post-dates pregnancy
There is considerable debate on precisely what constitutes “post-dates” pregnancy and on the justification for the various medical options for initiating labour in women whose pregnancies progress beyond the estimated date of delivery (EDD). The accuracy of the EDD calculation is highly debatable, with only 5 per cent of births occurring on the given estimated date (Khambalia et al. 2013), but it is not the purpose of this chapter to analyse current debate on how “term pregnancy” is determined. Suffice it to say that professionals advise women that they will normally give birth by 42 weeks gestation but suggest that induction of labour is offered between 41 and 42 weeks gestation to “avoid the risk of prolonged pregnancy” (NICE 2008: CG70). In practice, however, this is often discouraged by professionals whose advice may be biased, although this may be unintentional. Women who are pressurised are often subjected to a degree of “emotional blackmail” about the dangers of continuing pregnancy beyond 41 weeks gestation, and have been shown to be significantly more likely to have labour induced, sometimes even without clear clinical indications (Jou et al. 2015).
Induction of labour is one of the most widely used obstetric interventions, the most common indication being for post-dates pregnancy (Humphrey and Tucker 2009), although the reasons given can be somewhat spurious. In 2014–2015, the labour induction rate in England was 26.8 per cent, with an increasing upwards trend since then (NHS Digital 2015). It is suggested that the risk of adverse fetal outcomes increases significantly after 42 weeks gestation, leading to the recommendation that all women between 41 and 42 weeks gestation should be offered induction to reduce perinatal mortality and morbidity (NICE 2008). Induction of labour may be by membrane sweep alone or in combination with other methods, such as intravaginal misoprostol or dinoprostone (Propess™), artificial membrane rupture and/or intravenous oxytocin. Propess™ has become increasingly popular, with some maternity units even offering this as an out-patient service for 24 hours.
However, induction by any method poses risks to the woman, her baby and the progress of the labour (Smith, Crowther and Grant 2013). Artificially forcing the woman’s body to start labour may adversely affect her perception of pain, leading to an increased need for epidural anaesthesia, with a consequent risk of requiring instrumental or operative delivery, although Wood, Cooper and Ross (2014) concluded that induction may actually reduce the need for Caesarean section. Irrespective of the mode of birth consequent to induction, the procedure is costly to the maternity services in terms of time, hospital bed use and possible iatrogenic complications requiring further medical care (the so-called “cascade of intervention”). It also has a negative effect on women’s satisfaction with their birth experiences and may cause psychological issues in subsequent pregnancies (Gammie and Key 2014; Gatward et al. 2010; Jay 2015; Murtagh and Folan 2014).
Empowerment of women in the decision-making process is important and may even contribute to the success of any method used to start labour artificially, either medically or naturally. Women should not be directed towards a particular method, but should be given adequate comprehensive information to enable them to make informed choices about their care (NHS England 2016). This should include the option not to have labour induced, the pros and cons of continuing pregnancy beyond a certain gestation and a full, evidence-based discussion on the benefits and risks of medical methods of induction.
Women’s desire to self-initiate labour
Hall, McKenna and Griffiths (2012) undertook a systematic review on the commonly used natural methods for induction of labour and found, unsurprisingly, that these are mostly recommended on the basis of traditional knowledge but that they lack scientific evidence to support their incorporation into maternity care. Whilst there appeared to be some evidence to support the use of breast stimulation or acupuncture, very few other methods were shown to be valid or safe, including raspberry leaf, castor oil, evening primrose oil and blue cohosh.
In the UK, NICE does not advocate the use of natural means of inducing labour, such as herbal supplements, acupuncture, homeopathy, castor oil, hot baths, enemas and sexual intercourse, as there is insufficient evidence of effectiveness and safety (NICE 2008: 1.4.2). On the other hand, women’s satisfaction and audits of the results of “natural induction” services set up by midwives are very positive (Pauley and Percival 2014; Weston and Grabowska 2013).
There is, however, a difference between professionals advocating these methods once trained to use them safely and the fact that many women will try natural ways to initiate labour if they wish to avoid medical induction. It is vital to remember that any means of inducing labour is an intervention in the normal physiological process of the onset of birth. Indeed, the concept of “natural induction” is somewhat of an oxymoron, since the process of induction is, by definition, unnatural. The woman’s body is designed to start the process of expulsion of the fetus at a time when maternal and fetal factors dictate. Whilst much is written about the potential risks of artificial oxytocin, membrane rupture or prostaglandins, many women – and professionals – fail to appreciate the dangers of inappropriate, uncontrolled use of natural methods to stimulate contractions. Women are often so keen to initiate labour in order to end the discomforts of pregnancy, particularly when there is social and medical pressure to give birth close to the time of the EDD, that they will try anything. Of even more concern is the fact that they also frequently combine several methods, which can be extremely dangerous, most especially when commenced before term.
This desperate desire to start labour seems to be an almost universal practice across the world. In South Africa, for example, Zulu women drink a herbal concoction called Isihlambezo, thought to contain as many as 55 different plant extracts, many of which have strong uterotonic effects (Brookes 2004). Concomitant undeclared self-administration of Isihlambezo with misoprostol has been shown to cause uterine hypertonia, meconium-stained liquor and fetal distress (Essilfie-Appiah and Hofmeyr 2005), a feature which can be seen with other multiple-method self-administered attempts to start labour. Plants combined with crushed ostrich eggshell have also been used (van der Kooi and Theobald 2006). Elsewhere in Africa, up to 75 Ugandan plants used by pregnant women have been identified as being uterotonic, but many are also potentially toxic (Kamatenesi-Mugisha and Oryem-Origa 2007). The use of a porridge combined with herbal oxytocic-like plants, together with other methods to expedite labour, is considered to be a major cause of maternal mortality in Malawi (Maliwichi-Nyirenda and Maliwichi 2010). Natural, reputedly uterotonic, medicines are also used in many parts of Asia and South America (Michel, Caceres and Mahady 2016). (See also de Boer and Lamxay 2009; Martinez 2008; Ososki et al. 2002; Ticktin and Dalle 2005; Wang, Nankorn and Fukui 2003.)
Whilst indigenous plants may be the only accessible alternative to biomedicine in many remote areas of some countries, urbanisation, emigration and the Internet have increased the western public’s access to traditional medicines. In addition, in western maternity units with a high proportion of mothers from ethnic minority groups, midwives frequently care for women using traditional medicines to aid labour onset and progress, although often the women do not inform their midwives, and occasionally refuse to impart information about remedies being used (personal communications with midwives and mothers).
A case is known to this author in which an expectant mother, recently arrived from the Asian sub-continent, continually sipped at a glass of water, on the surface of which was floating a flower, which was eventually discovered to be hibiscus, a plant known to cause smooth muscle contraction (Da Costa Rocha et al. 2014; Kuriyan, Kumar and Kurpad 2010). The woman and her own mother declined to reveal the identity or purpose of the drink, but every time the woman took a sip, significant fetal heart decelerations occurred and the contractions increased in intensity. She continued to drink the water despite the midwife’s advice against it, and eventually she required an emergency Caesarean section for severe fetal distress and meconium-stained liquor. Whilst the pathology cannot definitely be attributed solely to the herbal mixture, it is highly likely that it contributed to the situation. Other similar situations have also been disclosed.
Adverse effects of natural remedies are often precipitated by combining them with prescribed pharmaceuticals, uterotonic infusions or pessaries, or with other herbs with similar pharmacological properties, by taking excessively high or prolonged doses, or by administration at an inappropriate gestation. Professionals should advise women to refrain from combining methods, particularly if they are at home with intravaginal Propess™ in situ or, in hospital, once the induction process has commenced. Combining natural remedies with other manual strategies to induce contractions can also be problematic, but it is the pharmacologically active herbal remedies which cause most concern because women fail to appreciate that they act like drugs and can interact with or potentiate medical means of induction.
A search of various Internet sites revealed over 70 suggestions for self-inducing labour, including many that were not based on any real physiological foundation and some that were extremely dangerous. One suggestion, found on several American websites, was that women should fast to the point of dehydration. This was explained as the increased production of anti-diuretic hormone from the posterior pituitary gland stimulating oxytocin production and may be based on an old German paper (Suranyi and Nagy 1957) in which dehydration was considered “harmless” as a means of induction. Several more recent papers, particularly from Muslim countries, have examined the impact of dehydration and fasting during Ramadan on the incidence of preterm labour, possibly suggesting a link between low food and water consumption on uterine activity. It would, however, seem unethical and contrary to good practice to advocate an unproven method of self-induction which could have serious consequences for mother or baby, particularly as it is known that dehydration during labour impairs uterine activity.
Unfortunately, access to this online information – and mis-information – means that westerners often make leaps of assumption about the effectiveness of particular remedies and their application to pregnancy and childbirth. There is a misconception that natural remedies known to be abortifacient (capable of causing miscarriage) will help to induce labour, or that those considered emmenagoguic (capable of causing bleeding per vaginam) are also uterotonic. However, the physio-pathology of uterine action during miscarriage or late-pregnancy placental bleeding is very different from that of physiologically normal uterine action during term labour in which myometrial contraction and retraction influences the polarity between the upper and lower uterine segments. Similarly, the endocrine factors that trigger miscarriage or third trimester antepartum haemorrhage are noticeably different from the hormonal changes occurring at the onset of term labour (Gruber and O’Brien 2011). It must also be recognised that natural remedies or complementary strategies which act systemically may not only cause contraction of uterine muscle but of all areas of the body that contain smooth muscle, including the circulatory and gastrointestinal systems, indicating that caution is needed in women with specific medical conditions such as hypertension, vascular impairment or irritable bowel syndrome.
It is the injudicious use of self-help methods of starting labour which are so disquieting, especially when women commonly do not inform their midwives or doctors. Professionals should make a point of discussing with women the various techniques or remedies they intend to use to prepare for, initiate or aid progress in labour. Midwives and doulas must be able to advise on complementary therapies and natural remedies which women choose to self-administer, treatments for which they may consult a complementary practitioner, or strategies which may be offered by midwives in some maternity units. Only one method should be used at any one time, unless a combination is used under appropriate professional supervision. Patient information leaflets on induction of labour should stress that it may be inappropriate to consume herbal teas, use aromatherapy oils or apply other natural remedies in conjunction with medical methods of inducing labour.
Midwives and doulas who are not adequately trained to advise on self-help methods should refrain from doing so. Indeed, the safety issues arising from women injudiciously using self-help and natural methods indicate an urgent need for this subject to be included in midwifery and doula education in order that they can respond with correct, comprehensive and, where possible, evidence-based information (Tiran 2011). This author is aware of many situations in which incorrect or incomplete information is offered in an attempt to act as the mother’s advocate, but which risks complications occurring from injudicious use. (See also Chapter 3 on professional issues.)
Conversely, since many women will seek treatment from independent complementary practitioners, often urging them to start labour, therapists should also have up-to-date knowledge and understanding of contemporary methods of medical induction, as well as the indications, contraindications and precautions related to the use of their own therapies as strategies for natural induction. Furthermore, we need to emphasise to women that babies are born when they are “ready” and that any attempt to expedite the normal physiological process can lead to problems.
The reasoning behind engaging in sexual activity towards term is that nipple stimulation and orgasm decrease cortisol and increase posterior pituitary gland oxytocin production. Penetrative sex causes a local release of prostaglandins from around the cervical opening and initiates natural contractions of the uterus, particularly during orgasm, whilst semen is a rich source of prostaglandins in its own right (Jones, Chan and Farine 2011). Nipple stimulation has also long been advocated to increase oxytocin levels and may encourage cervical ripening (Singh et al. 2014) and reduce the incidence of medical induction and other interventions (Demirel and Guler 2015; Mozurkewich et al. 2011), although it should be done with care and probably avoided before term if there is a history of preterm labour.
Although most authorities believe that no harm will occur in women with low-risk pregnancies who engage in sexual activity towards term, it is generally considered that there is no real evidence to support its use as a formal means of inducing labour (Kavanagh, Kelly and Thomas 2001). Sex does not appear to have any direct effect on the Bishop score, the onset of labour, incidence of Caesarean section or neonatal outcomes (Jones et al. 2011). Conversely, Tan et al. (2006) found a correlation between sexual activity at term and a reduction in pregnancy continuing beyond 41 weeks gestation, with a reduced need for induction of labour. However, Omar et al. (2013) found no evidence that advising women to engage in coitus at term facilitated labour onset or reduced the need for induction.
The insertion of an extra-amniotic balloon catheter into the cervix is standard obstetric practice in some countries, and the procedure is growing in popularity in some maternity units in the UK to the extent that NICE (2008) considers there is enough evidence to support its use in obstetrics (Amorosa and Stone 2015; Lim, Ng and Xu 2013). Mozurkewich et al.’s systematic review (2011) found that balloon catheters were less likely to cause uterine hyper-stimulation but may be associated with maternal or neonatal infection. There is evidence to demonstrate that it can be an effective means of cervical ripening and may encourage more rapid cervical dilatation in early labour than misoprostol, although establishment of active labour is somewhat slower (Tuuli et al. 2013). Some authorities use single balloon catheters; others use double balloons (Pennell et al. 2009; Salim et al. 2011). However, it is the injudicious, unsupervised self-use of balloon catheters by women at home that gives rise to concern. Balloon catheters can be purchased via the Internet and are advocated on several maternity consumer websites. Possible risks include infection, vaginal bleeding and pain, and the use of balloon catheters may be inappropriate for some women.
Similarly, Laminaria (kelp), a type of seaweed native to Japan, has traditionally been used topically to aid cervical ripening, particularly in primigravidae, and to facilitate labour, either alone or in conjunction with prostaglandins. It remains popular in the Americas but is less so in the UK. It was also used professionally in the 1970s and 1980s prior to procedures such as dilatation and curettage, termination of pregnancy, removal of intrauterine devices and to facilitate uterine placement of therapeutic radium, although it is no longer recommended as a medical strategy (Lin et al. 2006).
The seaweed is hygroscopic, in that it has the ability to form a viscous colloidal solution of gel in water, which is effective as a bulk laxative. This suggests it can aid dilatation of the cervix using laminaria “tents” inserted intra-cervically. These “tents” absorb ambient moisture, gradually swelling to a diameter of 1cm over four to six hours. Its mechanism of action may be due to the presence of a foreign body in the cervix initiating prostaglandin release, or possibly due to a high content of arachidonic acid, a prostaglandin precursor.
Women using laminaria “tents” may experience pelvic cramping and cervical bleeding, and there may be an increased risk of maternal and neonatal infection (Kazzi, Bottoms and Rosen 1982), although this is rare when commercially produced laminaria is used (Lichtenberg 2004). It has also been associated with fetal hypoxia and intrauterine death, and the “tents” can fragment and be retained in the cervical or vaginal canals, causing cervical wall rupture and infection (Borgatta and Barad 1991).
Laminaria should not be taken orally as there have been reports of adverse effects on the thyroid gland due to the high iodine content (Eliason 1998), allergic reactions (Kim et al. 2003; Knowles et al. 2002) and even arsenic poisoning, because the plant accumulates arsenic from the sea, although the concentration of arsenic may vary (Amster, Tiwary and Schenker 2007; Norman et al. 1988; Pye et al. 1992). Oral use may cause interactions with certain drugs including potassium supplements and some diuretics, and the high potassium level may cause hyperkalaemia. There is, however, very little evidence of effectiveness or safety; many references are from the latter part of the 20th century, perhaps because the technique was then more acceptable to medical practitioners (Jonasson et al. 1989; Kazzi et al. 1982).
Laminaria does not seem to be significantly effective in ripening the cervix. It may reduce the need for medical induction of labour, but it does not reduce the incidence of Caesarean section (Boulvain et al. 2001), although lack of blinding in the studies may have influenced the results. Conversely, there does not appear to be an increased risk of Caesarean in studies comparing laminaria with placebo, oxytocin, extra-amniotic infusion or prostaglandins (Boulvain et al. 2001). Studies on the use of laminaria prior to mid-trimester termination of pregnancy are also inconclusive (Almog et al. 2005), although there appears to be no increased risk to subsequent pregnancies (Jackson et al. 2007). More recent trials have evaluated laminaria versus misoprostol and mifepristone, demonstrating similar rates of efficacy, but finding increased costs, induction times and reported pain (Borgatta et al. 2005; Darwish, Ahmad and Mohammad 2004; Edelman et al. 2006; Prairie et al. 2007).
Self-administration of pharmacologically active plant remedies
Oral administration of natural remedies derived from various parts of different plants is by far the most commonly used means of attempting to self-induce labour. Even herbal teas contain active constituents which may be therapeutic or harmful, depending on the dose, frequency, gestation and method of administration. There are some herbal remedies which can be used to good effect by medical herbalists when prescribed appropriately, but it is the unwise self-prescription and ingestion of some of these same substances which can lead to maternal or fetal complications. NB All self-help remedies carry the risk of disproportionate or incoordinate uterine action and fetal distress if taken to excess.
NICE (2008) identifies that there is a lack of robust evidence on natural remedies to start labour. One of the problems of researching plant medicines is the ethics of testing them on pregnant humans when insufficient information is known about their risks. Studies on animals may contribute to the overall body of knowledge, but the physiology of human parturition is distinctly different from any other mammal. In vitro studies involving strips of myometrial tissue are controversial, not least because of the ethical issues involved in obtaining samples, but also because the impact of herbal medicines in human labour is not isolated to the uterine myometrium.
It is especially worrying to note that NICE erroneously categorises herbal supplements as “non-pharmacological” methods of induction of labour (NICE 2008: 18.104.22.168). NICE also separates castor oil from “herbal” remedies, despite it originating from a plant and having pharmacological properties.
The following sections explore some of the plant remedies commonly used by women in the UK, Australia and the United States. It is appreciated that professionals in other countries may also be aware of remedies used by their clients that are derived from local indigenous plants. It is hoped that the debate will enable midwives and birth workers in areas where different plant remedies are used to apply the principles discussed here to their own practice and to take steps to discover in more detail information on their local plants so that they can advise women on safety.
Raspberry leaf (Rubus idaeus)
This is probably the most popular of all the natural remedies used by women in the UK to avoid post-dates pregnancy and the threat of medical induction of labour. Although the ingestion of raspberry leaf, as a tea or in capsules, during the third trimester of pregnancy is relatively safe when taken under appropriate professional supervision, it is the injudicious over-use by women with little knowledge of its effects which makes it so problematic in contemporary maternity care. Expectant mothers and many midwives incorrectly believe that raspberry leaf can be used to trigger the onset of labour. This author is aware of several maternity units where guidelines suggest that midwives actively advise women to start taking their raspberry leaf tea at term to avoid induction (personal communications with midwives). However, medical herbalists consider that raspberry leaf is a preparation for birth to be taken during the third trimester and should not be commenced at term. Inappropriate use at this late stage is more likely to trigger hypertonic uterine action and fetal distress rather than aiding the onset of labour. There are also many women for whom raspberry leaf is contraindicated. (See Chapter 8 for more information on using raspberry leaf as a preparation for birth.)
This is, in the opinion of this author, excessively over-used and inadver-tently abused by pregnant women and, to a lesser extent, by midwives. As with raspberry leaf, this misuse is largely due to lack of knowledge and understanding that clary sage, like all essential oils, acts pharmacologically, and may have therapeutic or harmful effects, depending on the appropriateness of its use. Its popularity has increased in the last 15 years, possibly as a result of studies on labour aromatherapy, such as Burns et al. (2000), in which clary sage was used by midwives to good effect to augment contractions. One only has to read the various Internet consumer discussion groups to see the huge number of questions about clary sage and the alarmingly inappropriate “advice” from mothers who have used it in their own labours to appreciate the size of the problem – and occasionally some incorrect and potentially dangerous comments from midwives.
Clary sage is a member of the Labiatae family which also includes common garden sage (Salvia officinalis). Both common sage and clary sage are contraindicated in pregnancy in essential oil or capsule form, although a small amount of common sage occasionally used as a culinary herb is acceptable. However, it is vital that, if Salvia sclarea is considered appropriate for stimulation of contractions, it must not be confused with Salvia officinalis oil which contains far more potentially harmful, emmenagoguic chemicals and is completely inappropriate in the preconception, antenatal, intrapartum or early postnatal periods (see Tiran 2016a).
There is very little evidence of the safety of clary sage as a medicinal substance. The debate in this chapter is based on the author’s research and clinical experience of over 30 years, combined with numerous anecdotal reports, particularly in recent years, from midwifery colleagues who have cared for women using clary sage. From anecdotal evidence, clary sage certainly appears to have a contractile effect on the uterus. This may be due to the high sclareol content of the oil which is thought to mimic oestrogen, although Tisserand (2010) disagrees with this. However, it is generally held that the oil should not be used or inhaled by women with a history of oestrogen-dependent tumours (and care should be taken by non-pregnant menopausal women, including care providers, who are taking hormone replacement therapy). Conversely, Noori, Hassan and Salehian (2013) suggest that the sclareol content may act as an immunosuppressant and therefore offer some potential for enhancing cancer treatments.