Investigation of Different Relaxation Interventions on Physical and Psychological Changes in Breastfeeding Mothers in China: A Pilot Study
Phase: NA
Conditions: Stress-related Problem, Breastfeeding, Relaxation Therapy, Psychological Stress
Sponsor: University College, London

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Investigation of different relaxation interventions on physical and 
psychological changes in breastfeeding mothers in China: A pilot study 
 
Jinyue Yu 1 
 
 
 
 
Mary Fewtrell 1 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
_________________________________________________________________________ 
From: 1 The Childhood Nutrition Research Centre, Institute of Child Health, University College 
London. 
 
Principal Investigator: Mary Fewtrell, Institute of Child Health, University College London. 
30 Guilford Street, London. WC1N 1EH 
Email:m.fewtrell@ucl.ac.uk  

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1. Introduction and Rational 
Breastfeeding is of great importance for infant health and development [1]. Accumulated evidence 
show the effects of human breast milk on optimizing infant growth of brain and body, as well as 
protecting against infection and developing the immune system [1-4]. In a recent Lancet review [2], 
which summarised the findings of 28 systematic reviews and meta-analyses, the psychological and 
cognitive benefit of human breast milk for infants are emphasised. Moreover, the protective effects of 
breastfeeding on reducing the risk of obesity, type 2 diabetes, cardiovascular disease, and allergic 
disorders such as asthma are identified for infants later in life. Apart from the health benefits on infants, 
breastfeeding could also provide mothers with a better postpartum recovery [1, 2], and associated 
with decreased risk of osteoporosis, cardiovascular diseases, diabetes, and ovarian and breast 
cancer in their later life [2, 5-8]. However, despite a number of health programmes designed to 
promote breastfeeding, it is widely recognised that the exclusive breastfeeding (EBF) rates in many 
countries are disappointingly low and resistant to change [2]. Overall, less than half of the world 
population exclusively breastfeed their infants up to six months, with a global rate of 39% reported by 
UNICEF (2012) [9]. Apart from the socio-economic and cultural factors which may influence mother’s 
decision on breastfeeding, lactation performance is also influenced by maternal physiological and 
psychological condition [10].   
 
Stress can be one of the factors that influence the successful breastfeeding [11]. Accumulated 
evidence show that stress can influence the stress-related hypothalamic-pituitary-adrenal (HPA) axis 
thereby affect the lactation. A number of studies reported the effectiveness of relaxation techniques 
on reducing stress and anxiety, which were associated with improved endothelial function [12, 13]. In 
a previous MOM study, maternal psychological state was manipulated using relaxation therapy in 58 
Malaysian mothers breastfeeding their full-term infant. The therapy show significant effects in 
reducing maternal stress during lactation, favourably affecting breast milk composition (higher 
fat/energy and higher total carbohydrate) and positively influencing infant sleeping behaviour and 
growth.  
 
However, there are lack of studies evaluating the effectiveness among different relaxation techniques. 
There are many relaxation methods, including relaxation training [14], guided imagery [12], music 

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therapy [15], yoga and progressive muscle relaxation (PMR) [16]. Most of these use the cognitive 
and/or behavioural relaxation approach which emphasizes the development of a relaxation response 
to counteract the stress response of anxiety [17]. The relaxation response refers to a set of integrated 
physiological mechanisms and 'adjustments' that are elicited when a subject engages in a repetitive 
mental or physical activity and passively ignores distracting thoughts [17].  
 
Light therapy is another technique which may be used to promote relaxation. Evidence shows that 
light could stimulate the suprachiasmatic nucleus (SCN) located in the hypothalamus on top of the 
optic chiasm and influence the secretion of cortisol and adrenocorticotrophic hormone by mediating 
the HPA axis [18]. Research also indicates that light may induce gene expression ("circadian clock" -
related or "sleep"-related genes in depression) in the adrenal gland via the SCN-sympathetic nervous 
system [19]. An increasing number of studies reported the application of light therapy for the treatment 
of a range of mental disease, namely seasonal affective disorder (SAD) [20], non-seasonal 
depression [21], total sleep deprivation [22], and antepartum depression [23]. Studies also show that 
exposure to blue light is associated with reduced heart rate and blood pressure [24], while improved 
resting metabolic rate was observed in patients with SAD following exposure to bright light [25]. 
 
This pilot study aims to find the most effective relaxation technique to help mothers who are firstly 
breastfeeding their infant. Hence, we will evaluate the effects of five different relaxation techniques 
on physical and psychological changes in Chinese mothers who are firstly breastfeeding their infant. 
The ultimate aim of this study is to select the most appropriate therapies for breastfeeding mothers to 
be used in a subsequent trial investigating the impact of relaxation theory on breastfeeding outcomes 
in mothers who deliver a late preterm infant. Five types of intervention used in this study include: 
guided relaxation meditation tape, music tape, relaxation lighting, combined relaxation meditation and 
lighting, and combined music and lighting. 
2. Objectives 
To compare and evaluate the impact of five relaxation interventions on changes of heart rate (HR), 
blood pressure (BP), fingertip temperature (FT) and level of relaxation among Chinese breastfeeding 
women. Additionally, participants’ perceptions and feelings about each relaxation technique will also 
be evaluated. 

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3. Hypotheses 
Primary: Compared to the control state, all five relaxation interventions associated with increased 
perceived relaxation in varying degrees and reduced perceived stress.  
Secondary: The two combination treatments (guided relaxation tape with relaxation lighting, and 
music tape with relaxation lighting) might show more effectiveness than other three treatments. 
4. Study Design 
The present study will be conducted at Beijing Children Hospital, Beijing, China. A within-subject 
design will be used to evaluate the effectiveness and participants’ feeling towards the five tested 
interventions compared to a control situation.  
4.1 Population and recruitment  
The study population will be Chinese women who are currently breastfeeding their infants. 
Recruitment will be take place through social media and community flyers in Beijing Children Hospital. 
After obtaining approval. Advertisements will be posted in the hospital while flyers will be sent to local 
communities. Interested women can contact us by email. Details about the study will be explained in 
the information sheet. After checking the eligibility and obtaining written informed consent, all eligible 
participants will be enrolled in the study.  
 
4.2 Sample size calculation 
To estimate the sample size of this pilot study, standard formulas (21) used for calculation are:  
 
Sample size (per equal-sized group) =16 x standard deviation ÷ (difference) 2  
 
Here the effect size and standard deviation (SD) are estimated from a previous research (22), which 
evaluated the effect of audio-visual imagery on patient anxiety and physiological parameters. A 

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sample of 51 patients was able to demonstrate a significant reduction in HR (mean change (Z)= -0.75, 
SD= 1.00; p=0.01). Accordingly, the estimated sample size (per equal-sized group) would be 28. 
However, since the present study will use a within-subject design, a sample of 14 participants will 
likely be able to demonstrate changes. Considering the potential drop-off rates, we intend to involve 
a total of 15-20 subjects in this study.  
 
4.3 Eligibility criteria 
Inclusion Criteria 
Exclusion Criteria 
Women (primips) who are exclusively 
breast feeding their infants 
Women who are breastfeeding their 
second 
infant 
and 
have 
previous 
experience of breastfeeding for their first 
infant 
Between 1 month to 4 months after 
delivery and stay at home 
After 3 months of delivery and back to 
the work place 
Generally healthy 
Women who have mastitis, or any 
condition that may affect breastfeeding, 
blood pressure, heart rate, energy 
expenditure, hearing ability or vision 
18-45 years of age 
Smokers 
 
Did not attend any other clinical trials 
within the latest 12 months 
5. Study Procedures 
After obtaining informed consent, all participants enrolled in this study will be asked to attend for 30 
minutes once to three times per week for five relaxation treatments and one control (no treatment). 
The emotions and feelings of participants in both intervention and control treatment will be assessed 
before and after each treatment or control.  
 

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The duration of this study is six weeks. In order to fit with the subject’s schedule and control the 
circadian rhythm, all treatments and control sessions will take place on different days each week. 
Each participant can choose a 30-minute time slot to fit their timetable. To make the outcome 
assessment more consistent, participants are encouraged to come at the same time of the day they 
chose. The order of interventions will be randomly assigned for each participant. Both relaxation 
interventions and control will be conducted in the breastfeeding room located at Beijing Children 
Hospital. This room is private, quiet and has comfy seating. Participants will be asked to leave their 
personal belongings, including any electronic devices, books and magazines, and personal work, 
during the experiment period.  
6. Treatment of Subjects 
A total of five interventions will be used in this study, in which, three basic interventions are: guided 
relaxation meditation tape, music tape, and relaxation lighting (Philips Hue). Moreover, since we 
hypothesis that a potential larger effect might be observed when using combined relaxation 
interventions to stimulate different senses (vision and audition) at the same time, we combined the 
guided relaxation tape with lighting and the music tape with lighting as two additional interventions in 
this study. All participants will receive all five treatments and control in random order. 
6.1. Guided Imagery Relaxation Tape 
Participants will listen to a modified Chinese language version of a guided imagery meditation tape 
designed for breastfeeding mothers (23). Previous randomised controlled trials have shown efficacy 
for this relaxation method on reducing stress and anxiety among breastfeeding mothers (4, 24). The 
tape will be translated into Chinese. Moreover, since the original content of this tape is designed for 
women who are breastfeeding their infants, while the subjects in the present study are students 
without breastfeeding, the tape will also be modified by cut down the breastfeeding-related content to 
adapt to our sample. The duration of this tape will be cut down to about 10 minutes by removing the 
parts specific to breastfeeding.  

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6.2. Music Tape 
Participants will select music from the following two music lists: 1) traditional Chinese classical music 
(played by classical Chinese instruments), which has been traditionally used in China for patients with 
depression or chronic pain; 2) New-age music, a popular style that is often used for relaxation, which 
often draws on images of nature, the desert, the sea, and other naturescapes. These tracks are 
enhanced by electronic or computer-generated sounds. Since the music is created or enhanced 
through electronic means, the underlying rhythm and pulse can be manipulated to create a surging 
or pulsing effect to induce a relaxation response (25). Studies indicate that the effectiveness of music 
therapy on relaxation will be affected by personal preference. Hence, to enhance the effect of music 
therapy for relaxation, we will use the selection method to achieve a more individualized music 
experience for all participants. 
 
6.3. Relaxation lighting   
Compared to bright light therapy and blue light therapy which mostly show effects on people with 
depression, the light technique used in this study will be designed to induce relaxation. The Philips 
Hue system will be used. Previous studies evaluating the effects of environmental intervention on 
mood show that certain aspects of the imaging environment could be effective for pleasantness 
control (26). Clinical research also indicates that colourful ambient lighting has been shown to improve 
patient satisfaction and reduce pain ratings (27). Moreover, based on the research from Philips, which 
evaluated the feedback from patients and their staff, the colour preference of lighting may be cultural 
with people. Results show that people in Singapore preferring cool blue as more relaxing colour, 
whereas Germans preferring the warm orange. In the present study, participants will be asked to 
select either the “Relax”, “Energize” or “Concentrate” settings using the Philips Hue bulb, which 
correspond to orange, blue, and light cream respectively. The intensity of the light will be fixed.  
 
6.4. Guided relaxation tape with relaxation lighting and music with lighting 
Previous research compared the effects of guided imagery (verbal protocol) and verbal protocol with 
background music (24) and found that participants using the verbal protocol with background music 

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reported lower relaxation compared to the verbal protocol only group. The authors proposed that this 
might be due to confusion during the intervention when both verbal sounds and background music 
were experienced by participants. Therefore, in this study, we aim to evaluate the effectiveness of 
guided relaxation meditation with relaxation lighting as well as the music therapy with relaxation 
lighting, to find out whether the combined treatment could increase the relaxation level by stimulating 
vision (lighting) and audition (tape) together. It can be hypothesised that the effects of this combination 
therapy might be enhanced since the light and sounds will affect the HPA axis through different 
pathways. 
 
7. Outcome measurements 
Primary outcomes of this study will be perceived relaxation level, HR, BP and FT, while the secondary 
outcomes will be the perceptions and feeling about each treatment, including general satisfaction, 
perceived effectiveness, and likelihood of wanting to use the intervention in future. Evaluation will 
base on the design and content of the relaxation technique. 
 
The HR, BP and FT will be measured at both the start and the end of the experiment. An automatic 
BP machine will be used for the measurements of HR and BP. The BP will be measured three times 
and the mean of three will be calculated and recorded. A thermometer will be used for the FT 
measurement. For the evaluation of levels of relaxation and feelings of each intervention, a visual 
analogue scale will be employed at the beginning and end of each intervention.  
 
8. Statistical Analysis 
Data will be analysed using SPSS 24.0. Paired t-test will be used to detect changes in each of the 
primary outcomes before and after the treatment. One-way ANOVA will be conducted to find 
differences between control and each intervention group. Post-hoc analysis will be used to compare 
the effectiveness of each treatment. Differences will be considered statistically significant at p<0.05.  
 

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9. Ethical Consideration 
For any participant who are experiencing high BP or has previously been diagnosed as hypertension, 
we will advise them to contact with their GP and discuss whether they could take part in this study. 
Moreover, as compensate, each participant will be given a gift for taking part in this study. 
 
 
 
 
 
 
 
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