Randomized Controlled Trial to Assess the Effectiveness of a Self-Care Program for Pregnant Women for Relieving Hiesho

Abstract

Objective:

To assess differences in improvement of hiesho (sensitivity to cold) through a randomized controlled trial (RCT) of one group that used a self-care program (the Home Care Package Program for Relieving Hiesho) and another that did not.

Methods:

Participants were pregnant women experiencing hiesho in the 28th to 33rd weeks of pregnancy. The group carried out the intervention program for 4 weeks by wearing leg warmers, performing exercises, and pressing acupuncture points. The control group did not take any specific actions. Hiesho condition was assessed by using thermography to measure temperature in the four limbs; the changes were analyzed.

Results:

Findings for 140 pregnant women (73 in the experimental group and 67 in the control group) were analyzed. Participants' body temperatures were measured after completion of the program for 4 weeks and compared to their temperatures before start of the program. Compared with the control group, the experimental group had arm skin temperature 3.0°C (p < 0.001) higher and leg skin temperature 1.93°C (p = 0.02) higher; both differences were significant.

Conclusion:

The Home Care Package Program for Relieving Hiesho self-care program significantly relieved hiesho.

Introduction

Japan's perinatal mortality rate of 3.7 per 1000 births is the lowest in the world.¹ Although the World Health Organization has issued a call to reduce the number of cesarean deliveries, of 21 countries surveyed, Japan was the only one where the cesarean birth rate had not increased. Japan's rate of cesarean deliveries, 19.8%, is also low compared with the average of 26.4% among the 21 countries surveyed.² In other words, Japan is the country with a low rate of medical intervention and where nonpharmacologic treatment and natural birth are recommended practices. Japan supports nationwide health promotion programs, including self-care by pregnant women during pregnancy to avoid abnormal delivery. Self-care includes many alternative treatments, such as massage, exercise, keeping the body warm, and eating a proper diet, that do not involve medical intervention.

Meanwhile, one condition that many Asian women experience is hiesho. In Japan, more than 60% of pregnant women had hiesho.³ Hiesho is a condition in which temperatures of the arms and legs are low despite forehead temperature not being low. Regarding diagnosing improvement in hiesho, previous studies established that there was no significant difference in forehead temperature determining presence or absence of hiesho (p = 0.43) but that there was a significant difference in the temperature of the lower limbs between the two groups: difference of 5.2°C among pregnant women with hiesho and 2.4°C among pregnant women without hiesho (p < 0.001).³ The same result was obtained for internal deep temperature and skin surface temperature, indicating that improvement in hiesho can be diagnosed by measuring the skin surface temperature of the arms and legs.³

The pathology of hiesho can be described as follows: The autonomous nervous system controlling the sympathetic and parasympathetic nervous systems develops an imbalance, and as a result of this the sympathetic nervous system becomes dominant, causing peripheral blood vessels to contract and leading to poor circulation. Hiesho is diagnosed when an individual experiences cold hands and feet.^3,4 Nakamura et al.⁵ researched the connection between pregnancy and hiesho among Brazilian women living in Brazil. Although results indicated that 55% of the women surveyed had hiesho, they did not experience any discomfort or minor troubles. From this it can be inferred that Westerners are not readily aware of hiesho.

As for the effects of hiesho on the perinatal period, hiesho is considered a risk factor for abnormal delivery, as evidenced by a 3.4-fold increase in premature births when the mother has hiesho.^6
–8 Thus, it is important to remedy hiesho in order to avoid abnormal delivery. As far as alternative treatments are concerned, in the Cochrane Database of Systematic Reviews, Smith et al.⁹ reported that a group of pregnant women who practiced yoga had a quicker delivery and were more relaxed than a group that did not do so. Regarding the connection between alternative treatments and relief of hiesho in pregnant women, in Japan, pregnant women have long been actively encouraged to take steps, such as exercising, keeping the body warm, or pressing acupuncture points. However, these are all practices based on experience and are not evidence based.

The aim of this study is to create a self-care program, the Home Care Package Program for Relieving Hiesho, in order to assess the effectiveness of this program in reducing hiesho, a risk factor for abnormal delivery in pregnant women whose pregnancies are progressing normally.

Research hypothesis

Among the pregnant women who carried out the Home Care Package Program for Relieving Hiesho for 4 weeks, skin temperature of the limbs rose significantly by 1°C or more (p < 0.05) compared with those who did not carry out the program, and experiencing hiesho declined significantly (p < 0.05).

Definition

The objective parameter for hiesho (sensitivity to cold) is a large difference between core temperature and peripheral temperature. According to previous research,³ experiencing hiesho significantly reflects differences in temperature of the forehead and the sole of the foot, and hiesho is defined as “awareness of being sensitive to cold.”

Materials and Methods

Study design

The study was a randomized controlled trial.

Data collection period

The study was conducted during a 7-month period from October 16, 2014, to May 22, 2015.

Setting and participants

The research field was hospitals in Japan with outpatient obstetrics departments. Inclusion criteria for participants were Japanese women experiencing hiesho in their 28th to 33rd week of a normal pregnancy who agreed to participate in the research. Exclusion criteria were pregnant women other than those meeting the inclusion criteria.

The sample size was established by referring to the temperature difference of the legs, indicating presence or absence of hiesho as established in previous research.³ On the basis of a difference in mean value between the two groups of 1, a standard deviation (SD) of 2.2, α error of 0.05, power of a two-sided test of 0.8, and sample size ratio between the experimental group and the control group of 1, the required sample size was calculated at 76 for the experimental group and 76 for the control group.

Intervention program

An intervention program was designed and assessed for feasibility before being used in this study.¹⁰ The experimental group carried out the Home Care Package Program for Relieving Hiesho via a Web application for 4 weeks. The control group was given a pamphlet describing the effects of hiesho on childbirth. The self-care program, titled the Home Care Package Program for Relieving Hiesho, incorporates the following three elements:

1. Wearing leg warmers: The leg warmers were made of natural fibers made in Japan; the inner layer was silk and the outer shell was cotton, chosen to avoid irritating the skin. Participants wore the leg warmers 12 hours or more per day.

2. Performing hiesho exercises for pregnant women: The exercises in this study were developed under the guidance of pregnancy exercise instructors. The exercises consist mainly of stretching the calves; raising and lowering the heels; and exercises for the ankles, pelvis, shoulder blades, wrists, neck, fingers, and toes, performed one or more times daily. Although the possibility that excessive exercising will trigger premature labor or rupture of membranes is low,¹¹ during this study participants were advised to stop exercising and see their doctor if they experienced uterine contractions frequently before or during the exercises.

3. Applying pressure to acupuncture points: Participants were asked to apply pressure to the yongquan acupuncture point on the sole of the foot for 3 minutes one or more times daily. This acupuncture point is on the Kidney Meridian of Foot Shaoyin, located at the most recessed point in the depression appearing on the anterior part of the sole when the toes are bent inward. Its function is to readjust the autonomous nervous system.

Participants assessed their progress on their own using a Web application developed by the researchers and checked execution status daily through the Web application.

Procedure

The program was explained in detail to the participants, and those with hiesho who agreed to participate were assigned at random to one of the two groups. The envelope method was used to allocate participants, and allocation was done according to the permuted block method, which makes random, balanced allocation possible. The block size was 6, within which stratified random allocation was performed. Experts in clinical epidemiology were asked to draw up the allocation chart according to the permuted block method, and the chart was kept under lock and key. Researcher A, working in a private room, prepared opaque allocation envelopes according to the allocation chart. In the recruiting process, researcher B removed envelopes in sequence from the box where they were kept each time a participant agreed to participate in the study; this researcher had the participant open the envelope to confirm which group she was assigned to.

Participants were given an explanation of the program once again and asked to complete a written questionnaire. Next, the skin temperature of their arms and legs was measured by using infra-red thermography.

It was not possible to carry out a blind test because both participants and researchers knew ahead of time who had been assigned to the experimental group and the control group.

Measuring equipment

Infra-red thermography FLIRE8 equipment was used to measure skin temperature of the limbs. Traceability documentation from FLIR, which developed the equipment, was checked beforehand for safety, reliability, and suitability.

Participants' demographic data were measured according to a questionnaire developed by the researchers. Confounding factor items were measured on the 5-point Likert scale: 1, very much disagree; 2, somewhat disagree; 3, can't say either way; 4, somewhat agree; and 5, very much agree.

Data analysis method

The data obtained were input by researcher B and checked by several others for errors. After inputting, the data were then sent to the lead researcher, who handled them scrupulously and analyzed them.

Statistical analysis was carried out by using SPSS Statistics 23 software (IBM, Armonk, NY), and the primary outcome was analyzed by conducting a t-test for an independent sample and a paired sample. The chi-square test was used for the secondary outcome. Programs were compared by using analysis of variance. Intention-to-treat analysis was conducted using the full analysis set, which does not include participants who dropped out of the program.

Ethical considerations

Ethical considerations were fully observed at all stages of this study, and participants were given the information below, both orally and in writing. This study was approved by the research ethics committee of Keio University Faculty of Nursing and Medical Care 2014 (approval no. 217).

In more detail, the study was described to participants both orally and in writing, and they signed a consent form whereby they agreed to participate in the study. It was explained to them that the care they received would be identical regardless of whether they participated in the study or not, that they would not be treated disadvantageously, that study results would be written up in a research paper, and that the paper would be presented at conferences for experts. Participants were also told that the possibility that excessive exercising triggering premature labor or rupture of membranes was very low but that they should stop exercising and see their doctor if they experienced uterine contractions frequently before or during the exercises.

Results

Of 185 pregnant women recruited for this study, 150 agreed to participate. Seventy-three were assigned to the experimental group and 74 to the control group. Among these, 5 dropped out of the experimental group and 7 dropped out of the control group. The dropout rate was 8.0%. Reasons for dropping out were becoming indisposed (n = 5), changing hospitals (n = 2), and reason unknown (n = 5). The follow-up rate was 92.0%. Three participants in the experimental group and 7 in the control group dropped out without completing the program; therefore, the full analysis set covered 140 participants (73 in the experimental group and 67 in the control group). Accordingly, data from 140 participants—73 in the experimental group and 67 in the control group—were analyzed (Fig. 1).

FIG. 1.

Flowchart of the study.

Average values for carrying out the program were as follows: wearing leg warmers, 14.2 hours/d; hiesho exercises, 1.3 times/d; and pressing the yongquan, 1.4 times/d. The possibility of the exercises leading to premature labor or rupture of membranes is low, but as a precaution, when participants experienced uterine contractions frequently before or during exercise, they avoided exercising that day.

Participant characteristics

Characteristics are shown in Table 1. Participant age was 31.2 years in the experimental group (SD, 5.0) and 31.0 years in the control group (SD, 5.0). Weeks of pregnancy at the start of the study were 29.4 weeks for the experimental group (SD, 1.3) and 29.5 weeks for the control group (SD, 1.4). Confounding factors, such as sleep, exercise, bathing, diet, and wearing of a belly band, did not significantly differ between groups.

Table 1.

Participants' Backgrounds

Item	Experimental group (n = 73)	Control group (n = 67)	p-Value
Age (yr.)	31.2 (5.0)	31.0 (4.9)	0.84
In Week of pregnancy	29.4 (1.3)	29.5 (1.4)	0.52
Current weight (kg)	57.7 (7.3)	57.3 (8.6)	0.81
Sleeps ≥7 h/night^a	3.0 (1.2)	3.0 (1.4)	0.91
Exercises daily^a	2.4 (1.1)	2.4 (1.1)	0.84
Bathes daily^a	4.2 (1.3)	4.3 (1.1)	0.42
Has footbath or bathes from the waist down^a	1.7 (1.0)	1.5 (1.1)	0.41
Often eats sweets^a	3.6 (0.9)	3.7 (1.1)	0.35
Often drinks cold beverages^a	3.1 (1.2)	2.9 (1.2)	0.48
Wears tights or leg warmers^a	3.5 (0.9)	3.3 (1.0)	0.14
Wears a belly band^a	3.7 (1.4)	3.6 (1.5)	0.51
Presses acupuncture points^a	1.7 (1.2)	1.5 (1.0)	0.35

Significance based on t-test of independent sample unless otherwise noted, values are mean (standard deviation).

Likert scale: 1, not at all–5, very much so.

Comparison of skin temperature changes of the limbs with or without intervention

After 2 weeks into the program

Skin temperature of the arms was 32.0°C (SD, 3.3) in the experimental group and 32.53°C (SD, 2.9) in the control group; there was no significant difference (p = 0.3). Skin temperature of the legs was 29.07°C (SD, 4.0) in the experimental group and 29.43°C (SD, 4.7) in the control group; the difference was not significant (p = 0.63) (Table 2).

Table 2.

Comparison of Skin Temperature Changes of the Limbs With or Without Intervention

Variable	Experimental group (n = 73)	Control group (n = 67)	p-Value	95% CI
Arms
Before (°C)	31.21 (3.7)	32.35 (2.9)	0.4	−2.25 to −0.38
During (°C) (2 wk later)	32.0 (3.3)	32.53 (2.9)	0.3	−1.59 to 0.51
After (°C) (4 wk later)	33.98 (2.2)	32.11 (3.7)	0.00^a	0.97–2.77
Temperature difference before and after	2.78 (3.9)	−0.22 (3.3)	0.00^a	1.78–4.21
Legs
Before (°C)	28.33 (4.0)	28.90 (4.8)	0.45	−2.04 to 0.91
During (°C) (2 wk later)	29.07 (4.0)	29.43 (4.7)	0.63	−0.18 to 1.01
After (°C) (4 wk later)	30.34 (4.2)	28.98 (5.0)	0.08	−0.18 to 2.9
Temperature difference before and after	2.01 (5.2)	0.08 (4.6)	0.02^a	0.29–3.57

Significance based on t-test of independent sample. Unless otherwise noted, values are the mean (standard deviation).

p < 0.05.

After 4 weeks into the program

Skin temperature of the arms was 33.98°C (SD, 2.2) in the experimental group and 32.11°C (SD, 3.1) in the control group; skin temperature in the experimental group was significantly higher (p < 0.001) (Table 2). Differences in skin temperature before and after the program were 2.78°C (SD, 3.9) in the experimental group and −0.22°C (SD, 3.3) in the control group; the difference in skin temperature was significantly larger in the experimental group than in the control group (p < 0.001).

Skin temperature of the legs was 30.34°C (SD, 4.2) in the experimental group and 28.95°C (SD, 5.0) in the control group, and there was no significant difference in skin temperature between the experimental group and the control group (p < 0.08). However, differences in skin temperature before and after the program were 2.01°C (SD, 5.2) in the experimental group and 0.08°C (SD, 4.6) in the control group; the difference in skin temperature was significantly larger in the experimental group than in the control group (p < 0.02).

The difference between the experimental group and the control group in skin temperature after the self-care program was 3.0°C (p < 0.001) for the arms and 1.93°C (p = 0.02) for the legs, with significantly higher numbers for the experimental group. Therefore, for the arms and legs, the primary outcome of an increase of 1°C or more in skin temperature at a significant level (p < 0.05) in the experimental group compared with the control group after 4 weeks of the program was supported.

Comparison by program elements

The following three programs are recommended in Japan for relieving hiesho, and the researchers analyzed differences between the programs and their effectiveness in order to identify which is the most effective and the optimum frequency for executing the programs.

The three elements of the Home Care Package Program for Relieving Hiesho are wearing leg warmers, performing the hiesho exercises, and pressing the yongquan acupuncture point. Over 4 weeks, the experimental group participants wore leg warmers 24 hours a day, except during bathing; performed the hiesho exercises for pregnant women one or more times a day for 5 minutes each time; and pressed the yongquan acupuncture point for 3 minutes one or more times a day. Average execution for the three programs was as follows: wearing leg warmers, 14.2 hours/d; performing the hiesho exercises, 1.3 times/d; and pressing the yongquan acupuncture point, 1.4 times/d.

After analysis, no significant differences were observed between the three program elements of wearing leg warmers, performing the hiesho exercises, and pressing the yongquan acupuncture point (F = 1.92; p = 0.16).

Comparison of experiencing hiesho with and without intervention

Before the start of the self-care program, all 73 women in the experimental group and 67 women in the control group were experiencing hiesho, and there was no significant difference between the two groups. Two weeks into the program, 66 women in the experimental group (90.4%) and 65 in the control group (97.0) continued experiencing hiesho, and there were no significant differences (p = 0.16) (Table 3). After 4 weeks of the program, 57 women in the experimental group (78.1%) and 63 in the control group (94.0%) were experiencing hiesho, a significant difference (p = 0.008). In other words, results supported the secondary outcome of a significant lowering (p < 0.05) in experiencing hiesho in the experimental group before and after the self-care program. The relative risk after 4 weeks of the program was 0.83 and the relative risk reduction was 0.17, indicating that there had been a 17% decrease in those experiencing hiesho in the experimental group compared with the control group.

Table 3.

Experiencing Hiesho With and Without Intervention

Variable	Experiencing hiesho	Experimental group, n (%)	Control group, n (%)	p-Value	Relative risk	Relative risk reduction
Before	Yes	73 (100.0)	67 (100.0)	–	1	0
	No	0 (0.0)	0 (0.0)
During (2 wk later)	Yes	66 (90.4)	65 (97.0)	0.16	0.93	0.07
	No	7 (9.6)	2 (0.3)
After (4 wk later)	Yes	57 (78.1)	63 (94.0)	0.008^a	0.83	0.17
	No	16 (21.9)	4 (6.0)

Significance based on chi-square test.

p < 0.05.

Discussion

Effectiveness of the program for relieving hiesho

At the 2-week follow-up, arm and leg temperatures did not significantly differ between the experimental group and the control group. This indicates that the self-care Home Care Package Program for Relieving Hiesho was not effective for relieving hiesho.

At the 4-week follow-up, the difference in temperatures compared with before the program was 2.78°C for the arms and 2.01°C for the legs in the experimental group and −0.22°C for the arms and 0.08°C for the legs in the control group. The difference between the experimental group and the control group was 3.0°C for the arms and 1.93°C for the legs, both statistically significant increases (arms, p < 0.001; legs, p = 0.02) in the experimental group. Therefore, this showed that continuing the self-care Home Care Package Program for Relieving Hiesho for 4 weeks was useful for relieving hiesho. In health education, Tanaka and colleagues'¹² assessment of diet programs showed that carrying out a program for 1 month or more was effective for dieting. This means that continuing self-care by changing behavior is also important where hiesho is concerned.

Regarding temperature changes connected to relieving hiesho, after the 4-week program for the experimental group, temperature among pregnant women experiencing hiesho rose by 2.78°C for the arms and by 2.01°C for the legs; there was a difference of 3.0°C in arm temperature and 1.93°C in leg temperature between the experimental group and the control group. Differences in skin temperatures were measured among pregnant women who were experiencing hiesho and those who were not. The result was that skin temperature was 2.8°C higher among pregnant women without hiesho than those with hiesho. From this it can be inferred that by carrying out the Home Care Package Program for Relieving Hiesho for 4 weeks, pregnant women with hiesho no longer experienced the condition.

As for experiencing hiesho, compared with the control group, 17% fewer participants in the experimental group experienced hiesho after carrying out the program for 4 weeks, and there was a significant difference between the groups (p = 0.008). This finding indicated that performing the program for 4 weeks reduced experiencing hiesho. Regarding experiencing hiesho and peripheral temperature, previous research demonstrated that peripheral temperature in pregnant women with hiesho was lower than that in pregnant women without hiesho. Accordingly, carrying out the program for 4 weeks significantly reduced experiencing hiesho, and from that it can be inferred that hiesho in pregnant women was alleviated.

This study collected data from October to May. In previous studies, 67.7% of respondents experienced hiesho in June and July, as did 66.0% in November, meaning that there was no seasonal difference in experiencing hiesho. This is because of extensive use of air-conditioning in Japan in summer; trains and the interiors of houses and other buildings are cooled. This means that pregnant women are likely to spend time in a cold environment even in summer, thus necessitating steps to deal with hiesho. Accordingly, it is assumed that this program is appropriate for relieving hiesho, whatever the season.

Regarding the temperature difference between arms and legs, it is more difficult to remedy hiesho in the legs than the arms. A characteristic of pregnant women is that, up to about the 16th week of pregnancy, body temperature is higher because of the effects of progesterone and basic metabolic rate increases by 10%–20% compared with when they are not pregnant.¹³ Thus, pregnant women become less aware that they have hiesho than when they are not pregnant, but in the later stages of pregnancy, enlargement of the uterus interferes with venous return from the legs and hiesho develops more easily because of poor circulation in the legs. In this study, leg temperature was lower than arm temperature, and in the control group skin temperature dropped as pregnancy progressed, indicating that it was difficult to relieve hiesho. The preceding findings show that it is important to concentrate on the legs during pregnancy, that even pregnant women not experiencing hiesho can develop the condition as their pregnancy advances, and that measures against hiesho should be taken beginning early in pregnancy, regardless of whether individuals are experiencing hiesho.

This study analyzed the effectiveness of the three elements of the self-care program: wearing leg warmers, performing hiesho exercises, and pressing the yongquan acupuncture point. Analysis showed no significant difference among the program elements, indicating that the hiesho-relieving effects of all three are the same. In other words, each self-care measure is important, and a synergy effect can be expected from practicing all three. Regarding warming the body, Donoyama et al.¹⁴ report that massage boosts IgA in the blood and strengthens the immune function. For exercising during pregnancy, according to Kramer and McDonald's Cochrane systematic review¹¹summarizing 14 reports of on randomized controlled trials, exercising was beneficial for improving pregnant women's physical health and there was no significant difference in risks for premature labor. Regarding exercise and body temperature, pregnant women exercising in a heated pool with water temperature of 33°C experienced a 0.16°C rise in body temperature compared with before exercising (p < 0.001).¹⁵ Thus, wearing leg warmers and performing exercises appeared to be effective in stimulating blood circulation in pregnant women and relieving hiesho.

Regarding pressing acupuncture points, in Eastern medicine, stimulating those points, which are viewed as the junctions and links between nerves, is thought to have a rebalancing whole-body effect. The World Health Organization held an Informal Consultation on Development of International Standard Acupuncture Point Locations in 2003. The international standard for acupuncture point locations was established in 2006, and their effectiveness has been acknowledged.¹⁶ Regarding stimulation of acupuncture points during labor, a Cochrane systematic review of 14 reports on randomized controlled trials found that a group receiving acupuncture and shiatsu experienced pain relief and strong satisfaction.¹⁷ This seems to be because stimulation of acupuncture points stimulates blood circulation. In this study, participants stimulated the yongquan acupuncture point, which readjusts the autonomous nervous system; because its function is to improve circulation in the limbs, blood circulation is stimulated, which can help alleviate hiesho.

The preceding indicates that all of these program elements are thus effective for improving circulation and relieving hiesho.

Prospects and issues for the future

Japan actively focuses on hiesho in pregnancy and childbirth education, but this is based only on practical experience so far. The results of this study will help advance more specific evidence-based pregnancy and childbirth education.

One issue in this study is the disappointing result that 8.0% of women who had agreed to participate dropped out of the study. The self-care program in this study was performed as part of daily activities, with a Web application provided through which participants could check their results. The key to relieving hiesho is for pregnant women to continue practicing self-care. But simply assessing progress through a Web application makes it difficult for pregnant women to continue with self-care, pointing to the need to consider education support measures to help change behavior.

Conclusion

Among participants who carried out the Home Care Package Program for Relieving Hiesho for 4 weeks, arm skin temperature was 3.0°C (p < 0.001) higher and leg temperature was 1.93°C (p = 0.02) higher compared with temperatures in those not completing this program.

Footnotes

Acknowledgments

The authors thank the study participants. This research was conducted as part of a study under the Grants-in-Aid for Scientific Research (Basic Research [C], project no. 25463520) from the Japanese Ministry of Education. This study is registered with the University Hospital Medical Information Network Center (UMIN000018737).

Author Disclosure Statement

No competing financial interests exist.

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