These results show that the support provided by a companion of the woman's choice during labor and delivery had a positive effect on her satisfaction with the birth experience. Although the opinion of the health professionals were not assessed systematically, it seems that this intervention was well-accepted by them. No previous training was offered to the health workers, and the companions underwent no prior preparation. Therefore, the assistance the women in both groups received during labor and delivery was the standard care routinely provided in that hospital, and there were no changes in management. It is important to emphasize that this is not a study about doula s and if on one hand there is a general belief that a labor companion has always positive effects, there are,, on the other hand still a lot of health facilities where companions are not allowed, especially in developing settings. It was and still it is expected that the results of this study could help providers to acknowledge and respect women's rights during birth.
Satisfaction may have been influenced by assessment in the first 12–24 hours postpartum, in which feelings of dependency and benevolence and a halo effect are common. This effect describes a lack of criticism due to social ability and/or fear of reprisals, or because of a sensation of relief at having gone through a safe experience and having a healthy baby [9, 10]. However, this effect would probably be the same for both groups and could not explain the difference between them.
Experience during birth has been evaluated in controlled studies in which the type of care provider (doula, nurse or lay-person) varied. In most cases, anxiety, self-esteem, feelings of failure and difficulty, as well as levels of personal control and pain were assessed [11, 12]. In the present study, a chosen companion was the most important factor affecting the satisfaction of the parturient with labor and delivery, similar to what was found by Bertsch et al. [13]. In other controlled studies the presence of a partner or other family member [12, 14, 15] was not permitted or it was already a common practice in the institution [6, 16, 17] and was therefore not evaluated. These findings differ from those of Langer et al. [15], who reported that support had no influence on women's satisfaction in a study in which the presence of family members was not allowed and the majority of doulas were retired nurses.
In the intervention group, women's greater satisfaction with the guidance received from the doctors during labor has also been identified in another study with a different population, evaluated when the woman was accompanied by a person of her choosing [18]. When doulas or professional healthcare workers are the support providers, instructions are generally supplied by these individuals [9, 15–17]. Support also increased satisfaction with the care received during labor and delivery, and this finding is in agreement with data already reported [6] when the women received support from nurses.
Support also contributed towards satisfaction with vaginal delivery. Similar results were reported in other studies where women in the control group considered the experience of giving birth worse than they had imagined, compared to those in the intervention group [11, 19]. Therefore, it would appear that the presence of a person specifically designated to provide support positively influences the woman's perception of the birth experience itself, as seen in some meta-analysis and systematic reviews [5, 20]. This higher level of satisfaction may have been influenced by the woman's expectations and the way in which she perceived her care and by having a companion in a setting in which normally this would not be permitted.
Similar conclusions may also be drawn with respect to pain, which is considered a great generator of dissatisfaction. In our study, however, all the women were submitted to analgesia during labor. It would appear that the influence of pain and pain relief on satisfaction is not as obvious, direct or beneficial as the influence of the attitudes and behavior of professional health workers [9]. Further studies are required to investigate the influence of pain on satisfaction [3, 9].
The finding of a lower occurrence of meconium-stained amniotic fluid may be due to a possible reduction in the anxiety of women who received support, although this was not measured. It is known that an elevated level of maternal epinephrine resulting from stress affects blood flow to the fetus through an α-adrenergic constrictive effect on uterine vascularization, causing transitory hypoxia [21]. On the other hand, emotional support and the measures of comfort and information provided to the woman may reduce her anxiety and fear [4].
The lack of effect of support on any of the other events may have been due to the nature of the study protocol, in which active management of labor was adopted, as it is relatively common in a great proportion of Brazilian maternities, although not confirmed as a real effective intervention. This possible bias may have minimized the positive effects of support on some of the outcomes. This makes the finding of less lower occurrence of meconium-stained fluid even more important, possibly reflecting the positive stress-prevention aspect of support in labor in its potential impact over the newborn. This data is in agreement with results from a multicentric study carried out by Hodnett et al. [6] in which support was provided by nurses. The benefits of support may be surpassed by the rates of intervention carried out in the environment in which delivery occurs; routine analgesia being the factor that most reduces the effect of support on obstetrical interventions [4].
The results regarding the duration of the first stage of labor are contradictory to data reported from studies in which support was provided by lay-women [12], doulas [15] and midwives [22], where it was reduced. However, it must be considered that in our study first stage of labor was short in both groups. With respect to Caesarean section, it is noteworthy that rates were low in both groups, and there was no effect of labor support on these rates. This finding is in conflict with reports from other studies [12, 14, 23] in which the rate of Caesarean section was lower in the group receiving support.
In general, support had no effect on the management of labor in the institution. Interventions such as the use of oxytocin, amniotomy and analgesia, when evaluated in relation to cervical dilation, were carried out early in both groups, and the time between hospital admission, analgesia and amniotomy was less than two hours. Intervention had also no influence on neonatal outcomes and these data are in agreement with other trials [6, 11, 15, 17]. In this study, results regarding breastfeeding were similar in the two groups; however, breastfeeding was only analyzed in the first twelve hours following delivery, while ideally it should be evaluated the first months following delivery [11, 15].