The vertical position during labor : pain and satisfaction Posição vertical durante o trabalho de parto : dor e satisfação

Objectives: to evaluate the vertical position adopted by nulliparous women during labor in terms of pain and satisfaction with the position. Methods: the study was based on a secondary efficacy analysis of data from 107 nulliparous women enrolled in a randomized controlled trial in which the vertical position adopted during the dilation phase of labor was evaluated. The analysis involved comparing the median percentages of the duration for which women remained in the vertical position for each of the variables studied. The Kruskal-Wallis and Mann-Whitney tests were used to determine the differences between the groups. Statistical significance was set at p<0.05. Results: at 4 cm of dilation, the women with a pain score < 5 remained longer in the vertical position during labor compared to those with a score >7 (p=0.02). At 4 and 6 cm of dilation, the women who reported greater satisfaction remained more than 50% of the time in the vertical position (p=0.02 and p=0.03, respectively). Conclusions: the vertical position helped relieve labor pain and increased comfort and patient satisfaction.


Introduction
Factors that contribute to maternal and fetal wellbeing are becoming an increasingly common requirement both for maternity hospitals committed to the humanization of childbirth and for women themselves.Non-pharmacological and non-invasive interventions to relieve pain and ensure the comfort of women during labor should be a primary concern and it is the responsibility of healthcare workers to provide guidance on practices based on scientific evidence in order to guarantee the safety of both mother and fetus. 1 Among the numerous practices available, the vertical position during labor has received special attention, as it is a simple, inexpensive intervention that allows for a wide variety of positions.Although various positions adopted during labor and delivery have been studied over the past 40 years, controversy still surrounds the results regarding obstetric variables. 2Moreover, interest in the evaluation of the positions adopted during labor with respect to pain relief and comfort for women have yet to be fully clarified and there is thus as yet no consensus with regard to the optimal position to be adopted.Women in labor, when they are able to move around freely, have been reported to find and adopt various comfortable positions and to change position frequently. 2,3ith regard to obstetric variables, it is difficult to say whether there is any direct relationship between induced labor, duration of labor, incidence of cesarean section and the use of analgesics and the adoption of the vertical position during labor. 4[4][5][6][7][8][9][10][11][12][13][14][15][16][17] So far as the humanization of childbirth is concerned, there is an urgent need to identify evidence-based practices that contribute towards both the well-being of the mother and the fetus.The aim of this study was, therefore, to evaluate the influence of the vertical position adopted by nulliparous women during labor, in terms of pain and satisfaction with the position adopted.

Methods
This was a secondary analysis with an analytical assessment of efficacy applied to the data resulting from a previously published randomized and controlled trial that evaluated the effect of the vertical position in nulliparous pregnant women during the dilation phase of labor in terms of pain and satisfaction of the women in labor and obstetric outcome.The study was carried out at the Department of Obstetrics and Gynecology of the School of Medical Sciences, at Universidade Estadual de Campinas (UNICAMP), Campinas, São Paulo, Brazil.The protocol was approved by the Institutional Review Board and the women enrolled signed an informed consent form prior to admission.
The study group was composed of 54 women who received guidance and were actively encouraged to adopt the vertical position.The control group comprised 53 women who were not given these instructions.Intention to treat analysis showed that, despite the instructions, women in both groups adopted both the vertical and horizontal positions at different points during labor and for different periods of time. 2 This contamination may have occurred due to women's observation of each other and as a result of the policy adopted by the maternity hospital in which the study was conducted of allowing the laboring women to adopt different positions.
The data from 107 low-risk pregnant nulliparous women, aged between 16 and 40 years, in labor at gestational age ≥37 and ≤42 weeks, with initial cervical dilation ≥3 cm and ≤5 cm, with a single fetus in cephalic presentation and with strong vitality, were included in the present analysis.The socio-demographic and obstetric variables were analyzed according to the median percentage of the labor time that the women remained in the vertical position.
The time that the woman remained in the vertical and horizontal positions during labor was calculated based on self-reporting by the woman up to the moment when she received analgesics.Pain was evaluated in the interval between contractions using a 10-point visual analogue scale (VAS) in which 0 represented the absence of pain and 10 unbearable pain. 18To evaluate satisfaction with the position adopted, a VAS was used in which a sequence of five faces with different expressions was provided according to which the women were able to indicate their degree of satisfaction in relation to the position they were in at that time as: very unsatisfied, unsatisfied, indifferent, satisfied or very satisfied. 19he pain and the satisfaction scales were presented to the patients at three different points during labor: at approximately 4 cm, 6 cm and 8 cm of dilation, if the woman had not yet received analgesics by that time.For the analysis of satisfaction, the categories "very unsatisfied" and "unsatisfied", and "satisfied" and "very satisfied" were grouped as "unsatisfied" and "satisfied", respectively.The remaining procedures during labor, delivery and in the immediate puerperium were performed in accordance with the routine practices of the institution.
The analysis was carried out by comparing the median percentages of the time the women remained in the vertical position according to each category of the variables studied.The Mann-Whitney test was used to determine the differences between variables with up to two categories, while the Kruskal-Wallis test was used for variables with three or more categories.Significance was set at p<0.05.

Results
No statistically significant differences were found in terms of the median percentage of time women remained in the vertical position in relation to sociodemographic and obstetric characteristics on enrolment in the study, including age, marital status, level of schooling, obstetric history, the presence of a companion during labor, prenatal education, and use of uterotonics or type of delivery (Table 1).
The evaluation of pain according to the position adopted at 4 cm of dilation showed that the women who had a pain score <5 remained in the vertical position for around 41% of the duration of labor, whereas those who had a pain score >7 remained in this position for around 21% of labor-time (p=0.02;Table 2).On the other hand, no significant differences were found at 6 cm of dilation.With respect to satisfaction with the position adopted, at 4 and 6 cm of dilation the women who were satisfied were found to have remained in the vertical position for more than 50% of the labor time (p=0.02and Rev. Bras.Saúde Matern.Infant., Recife, 9 (4): 393-398 out./ dez., 2009

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The vertical position during labor Table 1 Percentage of the time spent in the vertical position according to obstetrical and socio-demographic characteristics.p=0.03, respectively; Table 2).The women who reported that they were unsatisfied with the position adopted remained in the vertical position for a median of 30% of the length of labor.Insufficient data were available for 8 cm of dilation, as by this time the majority of participants had already received analgesics.

Discussion
The findings of this study suggest a reduction in reported pain during labor with the adoption of a vertical position.1][22] A study that evaluated women's motives for using techniques to aid them during labor reported that, among the women who adopted the vertical position, the majority did so in response to pain and found relief in these positions. 23This finding may explain the fact that women in the present study who did not receive specific instructions with regard to the vertical position did in fact adopt the vertical position at various points during labor.
Our study also showed that women who remained in the vertical position for longer periods time reported greater satisfaction and this accords with the results of two other studies 20,14 in which the preference of women in labor for the vertical position was observed.The fact that the vertical position allows for numerous variations, along with the progressive approach adopted at the maternity hospital where the study was carried out, gives women the freedom to find positions that will relieve pain and increase comfort.However, for cultural reasons, women often remain in the horizontal position during labor 24 and many do not have access to information on the vertical position or on alternative positions that could be adopted during labor during prenatal care or even during labor.When specifically instructed or encouraged to adopt the vertical position, women usually want to identify variations and spend most of the time in the vertical position when compared to those who did not receive guidance. 1 According to Spiby et al., 23 women in labor try to find different positions as a way of relieving anxiety and pain and consequently increasing comfort.Anatomically, the greater comfort provided by the vertical position may be explained by the change in the diameter of the pelvis compared to horizontal positions.Using X-ray pelvimetry, Russel 25 showed that when the woman is seated, the diameter of the pelvis is greater in comparison to the dorsal decubitus position.
This led us to reflect on the physiological, albeit unconscious, need for the woman to try to find posi- The vertical position during labor tions that facilitate the rotation and descent of the fetus, in view of the fact that such positions were widely adopted in the 17 th century, when there were no studies to demonstrate these changes, and were only discontinued for reason of medical convenience, initially during the second stage alone and later throughout the duration of labor.Simkin 26 has defended the opinion that rhythmic movements during labor may modify the dimensions of the pelvis and facilitate rotation and descent of the fetus.These movements have also been widely used since antiquity.
According to Green and Baston, 27 the perception of internal control on the part of women in labor is related to the intensity of pain and, consequently, to satisfaction.The more intense the pain during labor, the lesser the feeling of control reported by women.The ability to find comfortable positions is directly related to the perception of external control and control of the contractions, thereby increasing satisfaction and well-being.Another study reported a similar observation, showing that personal satisfaction during labor was associated with internal control of pain, control of panic and of positions. 28lthough such analysis was not carried out in this study, the data reported here lead us to wonder whether more time spent in the vertical position during labor may be related to a heightened perception of control on the part of the women, resulting in less pain and greater satisfaction.
Some remarks should be made on the reason for using a complementary efficacy analysis to deal with data resulting from a randomized, controlled trial.This was done in view of the real possibility of a positive effect of the vertical position adopted by women during labor on maternal well being and on labor that is not clearly apparent in the randomized studies, because adherence and contamination are presented as confounding factors with regard to the effect of this intervention.It is obvious that in a randomized, controlled study, a laboring woman allocated to a horizontal position group cannot be prevented from adopting a vertical position at any time during labor if she wishes to do so.The opposite is also true in the case of women who were initially allocated to the vertical position group during labor.It would be neither ethical nor humane to prevent them from assuming the horizontal position for any length of time if they so desire.
In conclusion, the vertical position is a non-pharmacological practice that helps relieve pain and improves women's comfort during labor.Simple guidance from healthcare workers regarding the various vertical positions that may be adopted during labor may help women feel comfortable and minimize pain during this phase.This practice is in accordance with the directives established for the humanization of childbirth. 1

Table 2
Percentage of time spent in the vertical position according to satisfaction with the position and pain.