Background Maternal pushing during the second stage of labour is an important and indispensable contributor to the involuntary expulsive force developed by uterus contraction. Currently, there is no consensus on an ideal strategy to facilitate these expulsive efforts and there are contradictory results about the influence on mother and fetus. Objectives To evaluate the benefits and possible disadvantages of different kinds of techniques regarding maternal pushing/breathing during the expulsive stage of labour on maternal and fetal outcomes. Search methods We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (28 January 2015) and reference lists of retrieved studies. Selection criteria Randomised and quasi-randomised assessing the effects of pushing/bearing down techniques (type and/or timing) performed during the second stage of labour on maternal and neonatal outcomes. Cluster-RCTs were eligible for inclusion but none were identified. Studies using a cross-over design and those published in abstract form only were not eligible for inclusion. We considered the following comparisons. Timing of pushing: to compare pushing, which begins as soon as full dilatation has been determined versus pushing which begins after the urge to push is felt. Type of pushing: to compare pushing techniques that involve the 'Valsalva Manoeuvre' versus all other pushing techniques. Data collection and analysis Two review authors independently assessed trials for inclusion and risk of bias. Two review authors independently extracted data. Data were checked for accuracy. Main results We included 20 studies in total, seven studies (815 women) comparing spontaneous pushing versus directed pushing, with or without epidural analgesia and 13 studies (2879 women) comparing delayed pushing versus immediate pushing with epidural analgesia. The results come from studies with a high or unclear risk of bias, especially selection bias and selective reporting bias. Comparison 1: types of pushing: spontaneous pushing versus directed pushing Overall, for this comparison there was no difference in the duration of the second stage (mean difference (MD) 11.60 minutes; 95% confidence interval (CI) -4.37 to 27.57, five studies, 598 women, random-effects, I-2: 82%; T-2: 220.06). There was no clear difference in perineal laceration (risk ratio (RR) 0.87; 95% CI 0.45 to 1.66, one study, 320 women) and episiotomy (average RR 1.05; 95% CI 0.60 to 1.85, two studies, 420 women, random-effects, I-2 = 81%; T-2 = 0.14). The primary neonatal outcomes such as five-minute Apgar score less than seven was no different between groups (RR 0.35; 95% CI 0.01 to 8.43, one study, 320 infants), and the number of admissions to neonatal intensive care (RR 1.08; 95% CI 0.30 to 3.79, two studies, n = 393) also showed no difference between spontaneous and directed pushing and no data were available on hypoxic ischaemic encephalopathy. The duration of pushing (secondary maternal outcome) was five minutes less for the spontaneous group (MD -5.20 minutes; 95% CI -7.78 to -2.62, one study, 100 women). Comparison 2: timing of pushing: delayed pushing versus immediate pushing (all women with epidural) For the primary maternal outcomes, delayed pushing was associated with an increase of 54 minutes in the duration of the second stage of labour (MD 54.29 minutes; 95% CI 38.14 to 70.43; 10 studies, 2797 women, random-effects; I-2 = 91%; T-2 = 543.38), and there was no difference in perineal laceration (RR 0.94; 95% CI 0.78 to 1.14, seven studies. 2775 women) and episiotomy (RR 0.95; 95% CI 0.87 to 1.04, five studies, 2320 women). Delayed pushing was also associated with a 20-minute decrease in the duration of pushing (MD -20.10; 95% CI -36.19 to -4.02, 10 studies, 2680 women, random-effects, I-2 = 96%; T-2 = 604.37) and an increase in spontaneous vaginal delivery (RR 1.07; 95% CI 1.03 to 1.11, 12 studies, 3114 women). For the primary neonatal outcomes, there was no difference between groups in admission to neonatal intensive care (RR 0.98; 95% CI 0.67 to 1.41, three studies, n = 2197) and five-minute Apgar score less than seven (RR 0.15; 95% CI 0.01 to 3.00, three studies, n = 413). There were no data on hypoxic ischaemic encephalopathy. Delayed pushing was associated with a greater incidence of low umbilical cord blood pH (RR 2.24; 95% CI 1.37 to 3.68) and increased the cost of intrapartum care by CDN$ 68.22 (MD 68.22, 95% CI 55.37, 81.07, one study, 1862 women). Authors' conclusions This review is based on a total of 20 included studies that were of a mixed methodological quality. Timing of pushing with epidural is consistent in that delayed pushing leads to a shortening of the actual time pushing and increase of spontaneous vaginal delivery at the expense of an overall longer duration of the second stage of labour and double the risk of a low umbilical cord pH (based only on one study). Nevertheless, there was no difference in the caesarean and instrumental deliveries, perineal laceration and episiotomy, and in the other neonatal outcomes (admission to neonatal intensive care, five-minute Apgar score less than seven and delivery room resuscitation) between delayed and immediate pushing. Futhermore, the adverse effects on maternal pelvic floor is still unclear. Therefore, there is insufficient evidence to justify routine use of any specific timing of pushing since the maternal and neonatal benefits and adverse effects of delayed and immediate pushing are not well established. For the type of pushing, with or without epidural, there is no conclusive evidence to support or refute any specific style or recommendation as part of routine clinical practice. Women should be encouraged to bear down based on their preferences and comfort. In the absence of strong evidence supporting a specific method or timing of pushing, patient preference and clinical situations should guide decisions. Further properly well-designed randomised controlled trials are required to add evidence-based information to the current knowledge. These trials should address clinically important maternal and neonatal outcomes and will provide more complete data to be incorporated into a future update of this review.
