Effectiveness of auriculotherapy on anxiety during labor: a randomized clinical trial 1

ABSTRACT Objective: to evaluate the effectiveness of auriculotherapy on the anxiety of women during labor. Method: this is a randomized, parallel, triple-blind clinical trial. 102 parturients with gestational age ≥ 37 weeks, cervical dilatation ≥ 4 cm and two or more contractions in 10 min were selected and randomly assigned into three groups to receive auriculotherapy, placebo or control (routine care). Auriculotherapy was applied with crystal microspheres to the shenmen, uterus, neurasthenia area and endocrine points, and anxiety was assessed by the Hamilton Anxiety Rating Scale (HAM-A). Analyzes were performed using the Kruskal-Wallis, Generalized estimating equations, Chi-square and Fisher’s exact tests. Results: the groups showed no significant difference at baseline according to the HAM-A. After the intervention there was a significant increase in HAM-A scores at 120 min in the placebo versus auriculotherapy group (mean difference (MD) 3.62, confidence interval (CI) 0.42-6.81, p=0.0265) and control versus auriculotherapy group (MD 4.88, CI 1.87-7.88, p=0.0015). Conclusion: the parturients with auriculotherapy presented lower levels of anxiety according to the HAM-A score after the treatment when compared to the women from the other groups; this can represent alternative care in obstetric practice. Registration: n. RBR-47hhbj.


Introduction
Anxiety is a common symptom faced by women during labor which is often related to a lack of information about gestation and delivery during prenatal care, or may arise from a new and unknown situation such as birth to first-time mothers (1) . Anxiety disorders and distress experienced by women during gestation may also be related to postpartum depression, premature birth, cesarean delivery and difficulties in raising the children (2) . However, there is evidence that prenatal education and guidance on physiological changes during gestation and the labor and delivery process may result in less stress, female anxiety and reduce interventions during childbirth (1,(3)(4) .
Anxiety brings a perception of harm or threat that can produce feelings of worry and fear concerning the possibility of physical or psychological damage.
It is accompanied by physical changes and similar behaviors, which may also cause fear (5) . Thus, anxiety is a combination of the emotions of worry and fear.
For Traditional Chinese Medicine (TCM), anxiety can be explained by a deficiency of substances called xue or yin (energy that produces cold), or by disharmonious patterns of excess heat energies (yan energy), or even both at the same time (6) .
There are currently some Complementary and Integrative Health Practices (CIHP) used to relieve pain and anxiety during labor (7)(8) . Such therapies are conducted in a less invasive and low-cost manner, which can increase comfort and promote the physiological evolution of the labor process; however some bias in the studies limits their use in the practice.
Auriculotherapy or auricular acupuncture is a TCM modality that uses reflex points in the ear to the central nervous system to treat various disorders of the body through stimulation with needles, pressure with seeds or microspheres (9) .
Stimulation of auriculotherapy points for treating anxiety has been evaluated by some studies. One study (10) performed with health professionals associated the use of this therapy with a significant reduction in anxiety, burnout and traumatic stress, and observed a significant increase in professional courage and patience.
Another study (11) showed a reduction of 20.97% in the anxiety level of nursing students after stimulus with semipermanent needles in the shenmen and brainstem ear points.
The Chinese auricular map describes some points to treat anxiety (11)(12) , obstetric dystocias, labor induction and (labor) pain (13) , which may represent complementary care during labor and delivery. However, the lack of evidence and auriculotherapy studies in women during labor limits professionals' knowledge and the establishment of this therapy in obstetric practice. In this context, the present study aimed to evaluate the effectiveness of auriculotherapy on women's anxiety level during labor.

Method
This is a parallel, pragmatic, randomized clinical trial (RCT) (14) conducted from April 2015 to June 2016, in which 102 parturients admitted to a public university hospital in the State of São Paulo, Brazil participated.
Pregnant women of any age or parity after 37 weeks of gestation, in spontaneous, induced and/or accelerated labor, with two or more contractions in 10 minutes, dilation ≥ 4 cm, undamaged ear skin, and a living fetus with good vitality were included in the study. Cases of dilatation ≥ 7 cm, severe pre-eclampsia, previous cesarean section, immediate indication of cesarean section, or use of analgesic medication less than six hours from admission were excluded from the study.
The sample size was estimated considering the proposed method by an ANOVA model since these variables are quantitative and three groups were compared in this study. Estimates of the variable means for each of the groups and the standard deviation of the model's mean square error were based on two previous studies (15)(16) which evaluated the effects of acumpuncture on the Sanyinjiao pressure point on labor pain and duration. A significance level of 5% and a test power of 80% were adopted for the calculations. The calculation resulted in a sample of 17 individuals per group for the pain intensity variable, and a sample of 33 individuals per group for the labor duration variable. It should be considered that this RCT is part of a larger study which evaluated other parameters of interest. The calculation resulted in a total sample of 99 individuals, which was the highest value found.
The allocation sequence was defined for 102 participants, being three more than the sample calculation for predicting losses, using sealed and numbered opaque envelopes, sequentially generated by the site http:/www.randomization.com by a statistics professional, who was not a member of the study. They triple-blind method; in this sense, individuals from the IG, the PG, the evaluators, the professionals who provided care in the obstetric unit and the statistics professional did not know which group any participant belonged to. It was not possible to blind participants, evaluators, or professionals regarding the CG due to the characteristics of the study.
The Hamilton Anxiety Rating Scale was used (HAM-A, 1959) (17) to assess the anxiety level of the parturients, which comprises 14 items distributed into two groups.
The first group has seven items related to anxious mood symptoms, while the second group also has seven items, but are related to physical symptoms of anxiety.
Among the mood scales used worldwide, translated and adapted to the Brazilian reality regarding anxiety, the Hamilton's Anxiety Scale presents easy applicability and reliability (18) . Although there are other scales for assessing anxiety, many of them were constructed as modifications The following auriculotherapy points were used in the IG: i) shenmen, which predisposes the brainstem and the cortex to receive, condition and encode auricular reflexes, with sedatives and analgesic effects; ii) uterus, which is indicated for gynecological and obstetric changes, labor induction or reduction of the expulsion period and to reduce postpartum pain; iii) neurasthenia area, indicated for treating anxiety; and iv) endocrine, which regulates the functions of endogenous secretory glands, used in gynecological disorders (11)(12)(13) . Sham points were used in the PG (which are not indicated for the proposed treatment): ankle, knee, tooth and jaw, as shown in Figure 1.    Table 1, which may represent the initial first stage of labor or the advanced stage. Table 2 shows the means of the HAM-A scores and the categorized anxiety levels before and after treatment among the study groups. Table 3 shows the mean differences in HAM-A scores before and after 120 minutes of treatment. In analyzing the scores before and at 120 minutes among each group, a significant difference was found in the PG (MD 3.64, CI 2.26-5.02, p<0.0001) and CG (MD 3.71, CI 2.40-5.04, p<0.0001) due to the increase in the means, which did not occur in the IG (MD 0.07, CI -0.61-0.75, p=0.8429).   related to lack of knowledge and fear of childbirth (23) . The presence of anxiety symptoms was characteristic in the PG (>88%), CG (>88%) and IG (100%) groups, which may be related to the low prenatal education observed in all three study groups (>85%). Regarding the HAM-A scores, the comparisons were statistically significant for all analyzes when comparing IG versus PG and IG versus CG 120 minutes after allocation in the study, which did not occur in the comparisons between PG and CG at the same time. This may have occurred due to the real stimulation of ear pressure points in the IG which was not applied in the PG and CG groups, with a later increase in HAM-A scores for these groups.
The use of auriculotherapy during labor was also evaluated in a study with 80 parturients to compare the effects of this therapy on pain during the active phase of labor through a visual analogue scale (VAS) (13) . In their results, the mean pain intensity after treatment was significantly lower in the IG (IG: 7.56 versus CG: 8.43 p <0.05). The fact that this therapy alone favors pain relief already reduces the symptoms of anxiety (22) , which may have also occurred in this RCT in the IG after 120 minutes.
In a Cuban study (24)

Discussion
Anxiety is a common symptom faced by women during childbirth; especially when it involves loweducated parturients, primigravidae women and hospital environments with high rates of medical interventions (20) . This study aimed to evaluate the effects of auriculotherapy as a CIHP on routine care support offered to parturients, which showed control of the anxiety in the IG according to the Hamilton anxiety rating scale (17) .
The parturients in this study had similar previous increase the level of anxiety (22) did not statistically differ between the groups; these included the intensity and number of contractions, and inducing or accelerating labor with prostaglandins or ocytoxin.
The birthing process accounts for more than 90% of a woman's stress and anxiety during prenatal care, mainly Mafetoni RR, Rodrigues MH, Jacob LMS, Shimo AKK.
while the others did not present anxiety symptoms.
Auriculotherapy was effective in reducing the anxiety symptoms of women who needed to end gestation/go into labor, and they also did not increase the anxiety symptoms of women who received this therapy during the labor process (IG), as shown in our results.
Regarding this subject, studies on reflexology (8) and aromatherapy (25) , and (those) restricted to auriculotepia studies for these characteristics were found in the literature as an alternative treatment for controlling women's anxiety during labor. Reflexology showed a significant reduction in the anxiety level according to the STAI (p<0.001) after treatment when compared to those women under routine care (8) . In a study on aromatherapy (use of lavender essential oil) with 121 nulliparous women, a reduction in STAI scores (p<0.05) and cortisol concentration was also observed, while plasma concentrations of serotonin and 5-hydroxyl indole acetic acid (5-HIAA) increased, thereby improving labor progress (25) . Auriculotherapy in the obstetric specialty was found in an RCT (26) with 76 postpartum women after cesarean section. This study showed a significant reduction in cortisol levels (mean difference (MD) = 4μg / dl, p <0.05), heart rate (MD = 9.2 beats/ min, p <0.001) and anxiety (STAI) (MD = 3.8, p <0.01) after auriculotherapy (shenmen point).
A review study (12) evaluated the effects of acupuncture in the treatment of anxiety; three RCTs included showed a reduction in the anxiety level after ear acupuncture in different scenarios than those of the present RCT (during pre-hospilatar transport, preoperatively and with healthy volunteers). The authors of this review described ear acupuncture as promising for incorporating anxiety treatment into clinical nursing practice, as well as an alternative that may reduce drug use for anxiety (12) . Acupuncture in Brazil is a nursing We can highlight the absence of data on diagnosed cases of anxiety disorders or previous and routine uses of medications for treating anxiety as a limitation of this RCT, although the sample was randomized and the anxiety symptoms were measured by the HAM-A upon study admission. Another limitation is the lack of data on parturients who used any type of routine CIHP in the obstetric unit, as these activities do not require adhesion and there is great variation regarding their frequency and usage period during labor.

Conclusion
In this study, women undergoing stimulation by crystal microspheres on the following ear pressure points: shenmen, uterus, neurasthenia area and endocrine, maintained control of their anxiety levels during the active phase of labor when there is generally an increase in anxiety, as evidenced in the PG and CG groups without this same treatment; the fact that it did not increase the anxiety scores in the IG already indicates a useful effect of this therapy. However, this study coupled with new RCTs for auriculotherapy to assess parturient anxiety and conducted in less interventional environments will contribute with greater evidence for the establishment of this therapy in obstetric care.