Pregnancy yoga – what are the benefits?Gillian Kiely M B.Sc. (Pharm)

11304851

The school of pharmacy and Pharmaceutical sciences,

Trinity College,

Dublin.

2015

Introduction and background

Yoga

The word yoga is derived from the Sanskrit word ‘yuj’ meaning ‘to yoke’ or join together. However, the practice of yoga can be defined as an ancient Indian discipline built on the concept of mind and body inter-connectedness in order to achieve a liberating state or insight (White 2011). This is done through a combination of stretches and postures (asanas), breathing exercises (pranayama) and meditation.

The exact origins of yoga are uncertain and under debate nevertheless it can be concluded that these disciplines originated in India over five thousand years ago. Suggested origins include the Indus valley civilisation and Vedic civilisation (Samuel, 2011).

The Yoga Sutra is a philosophical guide that most yoga practiced today is based upon. It is essentially a coalition of the practice of yoga by the Indian sage Patanjali around 2,000 years ago (Wuyastik 2011, p. 32-33). The Sutra outlines the eight limbs of yoga: the yamas (restraints), niyamas (observances), asana (postures), pranayama (breathing), pratyahara (withdrawal of senses), dharana (concentration), dhyani (meditation), and samadhi (absorption) (Feuerstein, 1978).

There are many different types of yoga based on the asanas, the third limb which denotes a series of physical postures, such as hatha yoga which is a basic and classic style of yoga that concentrates on breathing and stamina. Ashtanga yoga is a systematic programme of poses, it usually is composed of six poses that move fluidly, flowing from one to the next with each inhale and exhale. Ashtanga is sometimes referred to as power yoga as it can be quite strenuous. Anasara is noted for its more free-flowing movements called Vinyasa (De Michelis, 2005). Bikram yoga is similar to Hatha except it is done in high temperature conditions ideally around 40°C as a result it is not recommended for those with elevated blood pressure or in pregnancy (Choudury, 2007).

Yoga is guided by five sheaths of existence, or koshas, including the: physical body (Anna-mayakosha); energy body (Prana-maya-kosha); mind body (Mano-maya-kosha); higher intellect body (Vijnana-maya-kosha); and, bliss body (Anandamaya-kosha)(LePage, 2007).

The suggested health benefits of yoga are wide and extremely varied. As such it is now being employed more and more as a non-pharmacological intervention or alternative therapy for a number of immunological, neuromuscular, psychological, and pain conditions.

Pregnancy

Pregnancy is defined as the period between conception and birth which generally lasts 40 weeks and is divided into three trimesters, each lasting three months. During this time women go through many marked physiological changes which result in distinct physical and psychological demands. The natural growth and development of the foetus can be adversely affected by numerous factors including infections, hypertension, diabetes, teratogens, and psychosomatic stress. In order to deal with this increased physiologic stress pregnancy demands physical, mental, and social adaptation. The impact of this stress cannot be overlooked; in fact recent animal studies have credibly confirmed that antenatal stress does affect pregnancy outcomes in early development of multiple organ systems with permanent changes in neuroendocrine regulation and behaviour in children (Mulder et al., 2002).

As a result of this necessity to adapt, pregnant women will commonly use a number of complementary and alternative therapies to ease this transition; one of these complementary therapies is yoga. It has been reported that in the United States approximately 20% of pregnant women will practice yoga (Adams, 2009) and in 2008, 15 million Americans reported they practiced yoga (Vitello, 2010). Nerissa Fields, one of the UKs leading antenatal yoga instructors describes giving birth as ‘’not just a physical experience but a total experience and thus it is essential to be well prepared from every aspect’’. With yoga’s inherent holistic approach towards combined mind and body well-being it is not difficult to understand its growing popularity amongst pregnant women. Furthermore many of the skills taught in pre natal classes such as breathing, relaxation and concentration have their roots in yoga (Collins, 1998).

The alleged health benefits of yoga for pregnant women are both physical and psychological as it works with both the mind and the body to prepare them for childbirth. Yoga is believed to improve physical fitness, increase cardiovascular health, and allow practitioners to better manage stress, depression, and anxiety. Due to the consistent rise in the amount of people using complementary and alternative therapies the real benefits of practicing yoga is being investigated more and more, especially in pregnancy. Further supposed benefits of antenatal yoga specifically include reduction in musculoskeletal symptoms and orthopaedic complications, decreased instances of maternal anxiety and depression during pregnancy and less likelihood of complications such as isolated intrauterine growth retardation, gestational diabetes and pregnancy-induced hypertension (PIH) to name a few.

Discussion

Although the field of medicine is advancing every day it has been reported that the occurrence of pregnancy complications is still increasing worldwide(WHO, 2009a), this is most likely due to the fact that women in modern society are older when they become pregnant leading to increased risks of complications. According to the World Health Organization (WHO, 2009b) a minimum of one woman dies every minute and 20 are

affected by complications related to pregnancy or childbirth. Thus it is understandable that women with increased chances of complications will look beyond conventional medicine to try to ensure a safe and happy pregnancy.

On its most basic level, yoga is a form of exercise and the introduction of a regular exercise programme for the majority of people is considered beneficial. It is however recommended that pregnant women do consult with their doctor or midwife about this at the start of their pregnancy particularly when commencing an exercise style or routine they are not used to. According to the NHS website, maintaining a normal daily physical activity or exercise for as long as is comfortable can help the body to adapt to its changing shape and weight gain.

One review which looked at prenatal exercise studies from multiple countries established that only 40% of pregnant women exercise even though almost 92 % are recommended to by their doctors. It is not uncommon for pregnant women to feel that exercise during pregnancy may be harmful or dangerous for the infant and are put off exercising, however this study also states that a measured exercise routine has been proven to increase the baby’s birth weight but only if the amount of exercise carried out in decreases in the final stages of the pregnancy. This review further established that practicing antenatal yoga is more beneficial than simply walking in lowering heart rate and blood pressure as well as resulting in less instances of pregnancy-induced hypertension with associated intrauterine growth retardation and prematurity (Field, 2012a).

The belief that yoga can increase the baby’s birth weight was further proven in a study carried out in a hospital in Bangalore, India. This was a prospective controlled observational study that had a trial population of 335 women at around their 19th week of pregnancy when they were recruited. There were 169 women in the trial group and 166 in the control group.

All of the women in the trial were matched for weight, age and Doppler velocimetry scores of umbilical and uterine arteries. Each of the women in the trial group practiced one hour of yoga every day which involved a combination of postures breathing exercises and meditation from the beginning of the study until the day they delivered. The women in the control group went on two half hour walks per day as recommended.

The primary birth outcomes investigated in the study were birth weight and gestational age at delivery. However the occurrence of complications such as intrauterine growth retardation (IUGR) and pregnancy-induced hypertension (PIH) with IUGR were also measured.

The results of the trial showed that the birth weight of children of the women in the trial group was significantly higher than those of the control group. Furthermore it was reported that the incidence of complications was lower in the yoga group. As such it can be concluded from this study that yoga is safe in pregnancy but also as far as this study is concerned beneficial (Narendran et al, 2005).

The importance of exercise is more relevant now than ever before and not only in pregnancy, in this country, according to the most recent statistics, 35% of women are overweight and one in four (26%) are obese (Buckley et al, 2007). The prevalence of obesity globally is a massive issue as it is associated with numerous co-morbidities; this is also the case in pregnancy.

Indeed when women deemed clinically obese become pregnant research has shown they are automatically at an increased risk of developing complications such as pregnancy induced hypertension (PIH), preeclampsia, gestational diabetes, and a larger cesareansection rate (ACOG committee opinion #315: obesity in pregnancy, 2005). The American college of Gynaecologists (ACOG) has also released a report recommending at least 30 minutes of moderate exercise most if not every day; this is even more essential and beneficial for those women who are overweight and obese(ACOG committee opinion #315: obesity in pregnancy, 2005).

It is also believed that exercise can aid in preventing and reducing symptoms commonly seen in pregnant women namely backaches, constipation, bloating, and swelling. In addition it can help to limit weight gain and fluid retention which can cause a lot of discomfort (Rasmussen et al, 2009).

ACOG has also recommended exercise for the treatment and prevention of gestational diabetes, which is associated closely with obesity (Artal, 2003). GDM is defined as glucose intolerance which is first detected or diagnosed during pregnancy, particular after 24 weeks of gestation (ADA, 2012). This recommendation is confirmed by a randomized controlled trial carried out in Thailand to establish the effect of yoga (and mindfulness eating) on blood sugar levels among pregnant women with gestational diabetes mellitus. Mindfulness eating for pregnant women with GDM was developed from the principles of mindful eating (Daubenmier et al., 2011 and Solloway and Fisher, 2007) and medical nutrition therapy guidelines (American Association of Diabetes, 2012 and Gilbert, 2011). In order to investigate the effects of the interventions the women’s capillary fasting plasma glucose levels, 2 hour postprandial blood glucose levels, and HbA1c levels were monitored.

The results of the study showed that the group practicing yoga and mindfulness eating showed significantly reduced fasting plasma glucose, 2-h postprandial blood glucose, and HbA1c versus the control group (Youngwanichsetha et al, 2012). Although there is no way to examine the specific effect of the yoga in its own right, it can be concluded that exercise can help to prevent and treat gestational diabetes, thus yoga could undoubtedly be beneficial, as it is a form of exercise.

The health benefits of yoga in pregnancy were further investigated in a stratified randomised control trial carried out in order to study the effect of yoga on platelet counts and serum uric acid in high risk pregnancies. Both of these are extremely useful screening measures in pregnancies with an increased risk of complications.

In total 68 women were deemed to meet the inclusion criteria for ‘high-risk pregnancy’, with 30 practicing yoga and 38 in the control group. All of the women were in their twelfth week of pregnancy. The inclusion criteria for this trial included; bad obstetrics history, twin pregnancies, a BMI of over 30, if the mother was aged less than 20 of over 35 and family history of complications in pregnancy.

The women in the ’yoga’ group practiced simple meditative hatha yoga three times a week for three months. Upon collecting the results from this three month trial period it was concluded that practicing yoga from the twelfth week of pregnancy is both safe and effective in promoting a healthy progression of platelets and uric acid in women with high-risk pregnancy, leading to healthy haemodilution and improved physiological adaptation (Nagarathna et al, 2013).

Another study which intended to demonstrate the health benefits of antenatal yoga focused on maternal comfort, labour pain, and birth outcomes specifically. This study used a randomized control trial involving 74 women split into an experimental group and a control group. The experimental group practiced six one hour sessions of yoga in total. Different methods and questionnaires were used to assess these criteria. 1

The results of this study showed that the women who had been practicing yoga during gestation had a shorter duration of labour and more specifically the first stage of labour was shorter. The ‘yoga’ group also demonstrated higher levels of maternal comfort both during labour and two hours after labour, and experienced less subject evaluated labour pain than the control group. However in both the control and experimental group labour pain rose as labour progressed and maternal comfort decreased. There were no substantial differences observed between the groups in terms of sedative usage (Chuntharapat et al, 2008).

The sequential effect of the pathways of yoga on outcomes (taken from Chuntharapat et al, 2008)

1The visual analogue scale to total comfort (VASTC), the maternal comfort questionnaire (MCQ), the pain behavioural observation scale (PBOS), the visual analogue sensation of pain scale (VASPS),birth outcomes were measured using Apgar scores and length of labour.

Although pregnancy is often seen as one of the happiest times of a woman’s life it can also precipitate psychological disorders such as depression and anxiety. Depression is a state of low mood and aversion to activity that can affect a person's thoughts, behaviour, feelings and sense of well-being (Salamans, 1997 and American Psychiatric Association 2013). Common symptoms of depression include feeling sad, anxious or bored, low energy, fatigue and loss of interest in hobbies, family or social life. According to the HSE website 1 in 4 women will need to be treated for depression at some stage in their life, this is a lot higher than the statistic for men, which is 1 in 10 (HSE website , 2005).

As such, it is inevitable that depression occurs during pregnancy particularly due to the fact that pregnancy involves physical and physiological stress as well as hormonal changes. The American Congress of Obstetricians and Gynaecologists (ACOG) reported that between 14-23% of women will suffer some symptoms of depression in pregnancy (Yan, 2009).

When treating depression pharmacological intervention is usually avoided until it is deemed totally necessary. Antidepressants are proven to be most effective in moderate to severe depression thus non-pharmacological interventions are essential in treating mild depression and are often extremely effective. Regular exercise, for example, can result in psychological and emotional benefits as not only are endorphins released but it also gives the patient purpose and structure.

As is the case when prescribing any medicine during pregnancy, the benefits of treatment must outweigh the risks involved and therefore alternatives to drug therapy are often sought after. Numerous studies and trials have been done to determine whether or not practicing antenatal yoga can actually reduce the occurrence of psychological disorders such as anxiety and depression.

The first study I reviewed in relation to this was a randomised controlled trial which analysed the effects of antenatal yoga on maternal anxiety and depression. In this study 59 women who were considered to be low-risk pregnancies were randomly assigned into either a trial group or a control group. The trial group practiced an eight week course of non-intensive hatha yoga. All 59 trial participants filled out three separate questionnaires to determine their psychological state at the beginning and end of the eight week period.2 The trial group completed pre- and post- session state anxiety and stress hormone assessments at this point also.

The results of this trial showed a marked difference between the two groups and it was concluded that antenatal yoga is effective in reducing the mother’s anxieties toward childbirth and also in preventing increases in depressive symptoms. In fact, it was observed that just one class of yoga reduced subjective and physiological anxiety. Although the results of this review do show that yoga is indeed beneficial in terms of reducing maternal anxiety

2 (State Trait Anxiety Inventory; STAI-State), trait (STAI-Trait), and pregnancy-specific anxiety (Wijma Delivery Expectancy Questionnaire; WDEQ) and depression (Edinburgh Postnatal Depression Scale; EPDS)

and depression, it must also be taken into consideration the very limited number of participants in the study (Newham et al, 2014).

Cortisol is a glucocorticoid hormone which is often used as a biological marker for anxiety and depression as it is released in response to stress. In addition to this, decreased cortisol is particularly important as it negatively affects immune function and is a significant predictor of prematurity (Field, 2012 b). As such, one trial set out to study the effects of hatha yoga in pregnancy on cortisol, affect and depressive symptoms. In this study 51 women were split into a trial group and a control group. On two different occasions the women in the trial group gave feedback on affect and gave a saliva sample before and after practicing a 90-min antenatal Hatha yoga session. The symptoms of depression were monitored in pregnancy and postpartum.

The results of the study showed that cortisol levels were lower after yoga compared to days with usual activity and positive affect was higher, furthermore negative affect and contentment improved more in response to the yoga session. It was also observed that women in the trial group experienced fewer depressive symptoms after giving birth but not before. Thus it was concluded from the findings of the study that antenatal hatha yoga may improve current mood and may be effective in decreasing the occurrence of postpartum depression (Bershadsky et al, 2014).

Another relevant study reviewed investigated the effect of prenatal yoga in combination with tai chi on depression, anxiety and sleep disturbances.

A total of 92 women who were pregnant and diagnosed as prenatally depressed were assigned randomly to either the trial group who practiced tai chi/yoga or the control group. All women involved in the study were at around week 22 of pregnancy. The trial group practiced a 20 minute group session every week for 12 weeks.

Before and after the 12 week programme all of the participants completed questionnaires to ascertain their levels of depression3, affect and somatic symptoms4, anxiety levels5 and degree of sleep disturbance6. Overall it was found that the women in the trial group had lower scores for each of the aforementioned categories then those in the control group.

Unfortunately this study did not give precise outlines on how the practices of tai chi and yoga were combined and carried out. Thus it cannot be concluded from this study that yoga itself is of benefit to women during pregnancy. It does however suggest that yoga, in combination with other forms of complementary therapies, can be of benefit to women suffering with prenatal depression, anxiety and sleep disturbances (Field et al, 2013).

3 CES-D Centre for epidemiological studies-depression scale4 Subscale of CES-D5 STAI The state anxiety inventory6 Questions on this 15-item scale are rated on a visual analog anchored at one end with effective sleep responses and at the opposite end with ineffective sleep responses

Another study which focussed on prenatal anxiety was carried out in Korea and aimed to establish the benefits of an antenatal yoga educational program in women who became pregnant through in vitro fertilisation (IVF). The study assessed the trial subject’s anxiety, stress, labour-confidence and labour pains.

The study took place over a six month period wherein 46 women who were pregnant following IVF were split evenly between a trial and control group. The trial group completed a twelve week yoga-centred educational programme.

Upon collecting the results of the trial it was concluded that practicing the yoga taught in the programme resulted in statistically significant improvements in labour confidence, labour pain, stress and anxiety7.Although the sample size in this trial was undeniably small, it can be taken that practicing yoga during IVF induced pregnancy is not only safe but also, to some extent, beneficial (Shim et al, 2012).

Conclusion

Although each of the trials reviewed in this essay has concluded that yoga is in fact beneficial to some degree in pregnancy there is still a necessity for further evidence. I feel that there is still a gap in information on the exact means by which pregnant women and their children can wreak benefit from practicing yoga. Furthermore I believe it would be valuable to distinguish between the benefits of yoga versus other forms of exercise regularly practiced in pregnancy.

Even though yoga is one of the few forms of alternative therapies that has been comprehensively studied and reviewed it is undeniable that many of the studies carried out thus far have been small and as a result are not totally reliable. I do believe however that it can be concluded with a reasonable amount of certainty that yoga, when practiced correctly, is safe in pregnancy. In terms of the benefits of prenatal yoga, I am inclined to believe that there are some, particularly those associated with stress and anxiety. Nevertheless it is apparent that there is a need for these benefits to be quantified and systematically reviewed in order for prenatal yoga to be safely and confidently recommended by physicians.

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