Abstract
Objective: to evaluate the efficacy of spontaneous pushing with pursed lips breathing compared to directed pushing during the second period of labor in the occurrence of episiotomy.
Methods: this is a quasi-randomized clinical trial, with 62 low-risk pregnant women in the second stage of labor. They were randomly allocated in control (CG) (n = 31) and intervention (IG) (n = 31) groups. The IG performed spontaneous pushing with pursed lips breathing while the CG was oriented to perform directed pushing associated with Valsalva Maneuver (MV).
Results: There was no difference between the groups regarding the occurrence of episiotomy (RR 1,1; 95%IC 1,0 to 1,2). However, there was a decrease in the duration of the maternal pushing by 3.2 minutes (MD 3,2; 95%CI 1,4 to 5,1) and a difference in maternal anxiety (Md (IQR) IG 46 (35-52), CG 51 (44-56) p:0,049), both favoring the IG. There was no difference in others maternal and neonatal outcomes
Conclusions: spontaneous pushing with pursed lips breathing was effective in reducing the duration of the pushing and showed a difference in maternal anxiety, but did not decrease the occurrence of episiotomy, nor did it alter the other studied maternal and neonatal outcomes.
Brazilian Clinical Trials Registry (ReBEC) under the identifier: RBR-556d22.
Keywords: Labor, Obstetric; Labor Stage, Second; Respiration; Parturition; Spontaneous Pushing.
Funding statement: the study had no funding body.
Introduction
Maternal pushing has been discussed for decades, mainly about its relevance in facilitating care in the second stage of labor and maternal and fetal outcomes [1,2]. In 1957, Beynon was the pioneer to compare the pushing done spontaneously with the Valsalva maneuver (VM), leading to a discussion about imposed breathing patterns associated with expulsive efforts and their relationship with the integrity of the pelvic floor. That study initiated a reflection on the importance of changing pushing instructions in obstetric care [3,4].
Directed pushing is common practice in obstetrics worldwide and it is done independently of the maternal desire to carry out the expulsive effort. It is usually associated with a VM sustained for 10 seconds or more and is oriented by third parties [4-6].
Recently in 2018, the World Health Organization (WHO) recommended that women in the expulsive phase of the second stage of labor should be encouraged and supported to follow their desire to push. According to the WHO, qualitative evidence shows that it is important for women to feel in charge of childbirth. The recommendation mentions that due to the absence of evidence of any benefit of imposing directed pushing in the second stage of labor this technique should be avoided by health professionals involved in childbirth care [7].
Spontaneous pushing is carried out naturally by the woman according to the inevitable desire to push down progressively. There is no deep breathing, and it does not initiate right at the beginning of the contraction. Generally, three to five pushings occur starting at the peak of the contraction and mostly happen with open glottis. [4-6].
In this scenario, the idea of using pursed lips breathing arises, which consists of a nasal inspiration followed by a resisted exhalation performed with pursed lips and/or semi-closed teeth, which may occur with or without contraction of the abdominal muscles [8] to facilitate spontaneous pushing during the expulsive effort, but studies are still scarce [2]. There is a study that compared a relaxation technique with breathing exercises, which involved diaphragmatic inspiration, prolonged fractional expiration, and pursed lips breathing with usual care but observed only during the first stage of labor [9].
Several physiological effects are related to pursed lips breathing in several populations, such as improvement of breathing patterns, reduction of dyspnea sensation, global relaxation, positive expiratory pressure maintenance, preventing alveolar collapse while promoting lung deflation [8]. Also, an increase in arterial oxygen pressure and arterial oxygen saturation, decreased carbon dioxide pressure, decreased respiratory rate and increased tidal volume were observed [10], in addition to changes in respiratory mechanics, with greater activation of the abdominal, rib cage and accessory expiratory muscles, and lower diaphragmatic participation, which may be useful to prevent respiratory fatigue [11,12].
Therefore, given the physiological benefits of pursed lips breathing described in the literature, we hypothesize that its use during the second stage of labor may result in better maternal and neonatal outcomes and thus provide the necessary evidence for its guidance.
Given the gaps in knowledge resulting from the high risk of bias in the studies regarding the type of pushing, the present study aimed to evaluate the efficacy of spontaneous pushing with pursed lips breathing when compared to directed pushing on maternal and neonatal outcomes.
Materials and methods