Included studies

Nine studies were included for this review. Eight were randomised controlled trials (RCTs) (Ahmadi 2017, Araujo 2021, Barasinski 2020, Barnett 1982, Koyucu 2017, Parnell 1983, Walker 2012, Yuksel 2017) and 1 was a systematic review (Lemos 2017). The systematic review had 16 RCTs included (Buxton 1988, Fitzpatrick 2002, Fraser 2000, Goodfellow 1979, Hansen 2002, Jahdi 2011, Kelly 2010, Lam 2010, Low 2013, Mayberry 1999, Plunkett 2003, Schaffer 2005, Thomson 1993, Vause 1998, Vaziri 2016, Yildirim 2008).

Three studies (Ahmadi 2017, Barasinski 2020, Barnett 1982) compared directed pushing with open glottis breathing technique to directed pushing with closed glottis or Valsalva manoeuvre breathing technique. Eleven studies (Araujo 2021, Jahdi 2011, Koyucu 2017, Lam 2010, Low 2013, Parnell 1993, Schaffer 2005, Thomson 1993, Vzairi 2016, Yildirim 2008, Yuksel 2017) compared spontaneous pushing to directed pushing using closed glottis. Ten studies (Buxton 1988, Fitzpatrick 2002; Fraser 2000; Goodfellow 1979; Hansen 2002; Kelly 2010; Mayberry 1999; Plunkett 2003; Vause 1998, Walker 2012) compared immediate to delayed pushing.

The studies were from Brazil, Canada, Denmark, France, Hong Kong, Iran, Ireland, Spain, Turkey, United Kingdom and the United States.

The included studies are summarised in Table 2.

See the literature search strategy in appendix B and study selection flow chart in appendix C.

Excluded studies

Studies not included in this review are listed, and reasons for their exclusion are provided in appendix J.

Direct with open glottis versus directed with closed glottis

Directed pushing using an open glottis breathing technique was compared to directed pushing using closed glottis or Valsalva manoeuvre technique. There were no important differences, or no evidence of an important difference between groups in terms of mode of birth, for women of mixed parity who had an epidural. There was no evidence of an important difference between groups for nulliparous or mixed parity women, with or without an epidural, in terms of third/fourth degree tears.

In terms of the duration of active and passive second stage, there was no important difference between groups for mixed parity women with an epidural. However, for multiparous women without an epidural, directed pushing with open glottis led to a reduction in the duration of the active second stage compared to directed pushing with a closed glottis.

For multiparous women without an epidural there was no important difference between groups on the duration of the passive second stage.

The evidence ranged from very low to moderate quality, with the main concerns around imprecision. There were some concerns around risk of bias, and indirectness due to not enough information given as to whether women had been induced.

Spontaneous versus directed

Spontaneous pushing was compared to directed pushing. Valsalva manoeuvre or closed glottis was used in both groups. For nulliparous and mixed parity women without an epidural, the evidence showed no important differences or no evidence of an important difference between groups in terms of mode of birth. The exception was a possible increase in the number of caesarean births for spontaneous pushing over directed pushing for nulliparous women with epidural.

There were no important differences, or no evidence of an important difference for third/fourth degree tears, or Apgar score <7 at 5 minutes for nulliparous women or women of mixed parity without epidural.

In terms of duration of the active second stage, the evidence for nulliparous women without an epidural showed no differences between groups, however for mixed parity without an epidural, spontaneous pushing led to a decrease in the duration compared to directed pushing. For nulliparous and mixed parity women, with or without an epidural, there was no important difference on the duration of the second stage of labour.

There were no differences between the groups on maternal satisfaction in nulliparous women without an epidural, or neonatal admission in mixed parity and nulliparous women without an epidural.

All the evidence for spontaneous versus directed was rated as very low quality with concerns around risk of bias, heterogeneity, indirectness and imprecision. The exception was spontaneous vaginal births in nulliparous women which was rated moderate quality with concerns around risk of bias only.

Immediate versus delayed

Immediate pushing was compared to delayed pushing. All the evidence was in women with an epidural. The evidence showed no important differences in terms of spontaneous vaginal birth for nulliparous and multiparous women. There was no important difference for instrumental vaginal births for nulliparous women, or mixed parity, but some evidence on multiparous women showed a possible important increase in the number of instrumental vaginal births for immediate pushing. There was no important difference or no evidence of an important difference on caesarean births for nulliparous or mixed parity women.

There was no important difference on third/fourth degree tears in nulliparous women, or Apgar score <7 at 5 minutes for nulliparous or mixed parity women.

There was an important increase in the duration of the active second stage of labour, with immediate pushing for both nulliparous and multiparous women, but evidence for mixed parity showed no important difference between groups.

Evidence on the passive stage of second stage, and the total second stage showed an important decrease in the duration for immediate pushing, in nulliparous, multiparous and mixed parity. This is expected as the women in the immediate group would have moved to the active/pushing stage of labour sooner than the delayed group.

There were no important differences between groups for neonatal admissions for nulliparous women.

The evidence was rated as mainly very low quality, with concerns around risk of bias, heterogeneity, indirectness and imprecision. Some of the evidence was of low and moderate quality.

Included studies

A systematic review of the economic literature was conducted but no economic studies were identified which were applicable to this review question.

Excluded studies

Economic studies not included in this review are listed, and reasons for their exclusion are provided in appendix J.

Economic model

No economic modelling was undertaken for this review because the committee agreed that other topics were higher priorities for economic evaluation.

The outcomes that matter most

The committee agreed that mode of birth was a critical outcome for this review as it would provide women and healthcare professionals with information on whether different pushing techniques were more or less likely to lead to a spontaneous vaginal birth, or whether they would have an impact on the rate of birth with forceps or ventouse, or a caesarean birth, and this in turn would have an impact on women’s experience of labour and birth. The committee also agreed that third/fourth degree tears was a critical outcome for this review, as the quality of life for women following this outcome can be greatly reduced. They also prioritised Apgar score <7 at 5 minutes as a critical outcome for the baby, as this outcome is an indicator for the survival and health outcomes for the neonate.

The committee also chose important outcomes for this review. They agreed that the duration of the active and the passive second stage of labour were important outcomes as different pushing techniques may lead to longer durations of labour, and information regarding this would be beneficial to women when deciding which approach is best. In addition they agreed that a prolonged active second stage of labour may lead to pelvic floor damage. The committee also wanted to explore women’s experience during labour and whether any pushing techniques had an impact on this, and so included this as an important outcome. The committee recognised the great importance of women’s experience, in particular with this topic, but they were aware that data on this outcome was likely to be sparse and unlikely to inform decision-making in a meaningful way, so they prioritised this outcome as important, rather than critical. The committee also recognised that neonatal admission was an important outcome for this review and would provide an indication of the health of the neonate.

The quality of the evidence

The quality of the evidence for outcomes was assessed with GRADE and was rated as moderate to very low.

Some of the evidence was downgraded due to risk of bias. For subjective outcomes this was due to not being able to blind for interventions. Other concerns around bias were some concerns around the randomisation of participants, incomplete data for some of the evidence and some concerns around selective reporting due to pre-specified protocols not being available.

There was heterogeneity in some of the evidence that could not be explained by subgroup analysis. Some of the evidence was downgraded for indirectness, this was mainly due to women who had their labour induced, or there were high risk groups included in the population and not enough information regarding the proportion of these women in the total sample.

Most of the evidence was also downgraded for imprecision around the estimate of effect.

Benefits and harms

The committee discussed the evidence and agreed to make recommendations specific to the parity of women (where possible) and whether they had an epidural in situ.

The committee discussed the evidence for directed and spontaneous pushing (directed with open glottis versus directed with Valsava/closed glottis and spontaneous versus directed, both with Valsava/closed glottis) and noted that most of the evidence showed no difference or no evidence of an important difference between the different types of pushing techniques. The evidence for directed and spontaneous pushing included groups of women both with and without an epidural so the committee agreed to make recommendations for these groups separately.

In women without an epidural there was a reduction in the duration of active second stage with directed pushing with an open glottis (in multiparous women) and with spontaneous pushing with a closed glottis (in mixed parity women), so the committee agreed to recommend these 2 options.

In women with an epidural in situ, there was evidence for an increased risk of caesarean birth (in nulliparous women) with spontaneous pushing compared to directed pushing, so the committee recommended directed pushing in these women. This agreed with the committee’s view that as women with an epidural do not get the same urge to push, directed pushing may be more helpful in these women.

As overall there was no evidence suggesting a clear benefit of one pushing technique over another, the committee agreed that they would not recommend a specific pushing technique and that women’s preferences should be the main factor to consider. They therefore agreed to make a recommendation advising women without an epidural in situ of the potential benefits of spontaneous pushing and pushing while exhaling on the duration of the second stage of labour, and that there may be an increase in the rate of caesarean birth for nulliparous women with an epidural, and so made recommendations advising women of this.

The committee discussed the evidence for the timing of pushing (immediate compared to delayed) and noted that all the evidence was in women with an epidural in situ, but that it had been possible to break it down into nulliparous and multiparous women. They discussed that the evidence showed an important increase in the duration of the active second stage for immediate pushing in both nulliparous and multiparous women, meaning that the active second stage was shorter with delayed pushing. The committee noted that, as expected, the duration of the passive second stage was reduced with immediate pushing, but that despite the increase in the duration of the active stage with immediate pushing, the total duration of the second stage was reduced with immediate pushing. The committee agreed that although there may be some damage to the pelvic floor in the passive second stage, due to the presenting part pushing on the pelvic floor, it was a prolonged active second stage which led to more pelvic floor damage, and so they agreed they would make recommendations advising women with epidurals of the benefits of delayed pushing. For multiparous women with an epidural in situ there was evidence immediate pushing increased the rate of birth with forceps or ventouse, and so this evidence reinforced the recommendation that these women should be advised to delay pushing.

The committee discussed that the exact timing of the delay would be useful to include in the recommendations and looked at the evidence for further detail on the timings. The committee discussed the evidence for multiparous women, which favoured a 1 hour delay over immediate pushing in terms of duration of the active second stage, as well as a possible reduction in instrumental births. They agreed that this was also in line with current practice and therefore included this in their recommendation.

The committee discussed the evidence for nulliparous women, and discussed the variation in practice with regard to the length of delay of pushing for this group of women. They noted that the studies used a range of timings for delay from up to 1 hour and up to 3 hours. The committee considered the effect estimates for the different timings separately based on the data provided in the forest plots. The evidence showed that the benefit was specific to the evidence that used a delay of up to 2 and up to 3 hours. The committee considered the benefits alongside the harms of recommendation for up to 3 hours delay. Although the evidence for a 3 hour delay did not show a difference between interventions in the mode of birth outcomes, or neonatal admission, the committee were aware of the risks of post-partum haemorrhage, pelvic floor damage and incontinence related issues with very long second stages. They therefore agreed that a 3 hour delay may offer the same benefits as a 2 hour delay but may also increase the likelihood of these adverse consequences and so agreed to recommend a 2 hour delay as for the appropriate time for delayed pushing in nulliparous women.

Cost effectiveness and resource use

The committee noted that there were no costs associated with the different pushing techniques themselves but any difference in outcomes could result in a difference in resource use between alternative approaches. However, as the review did not find consistent evidence of a difference in outcomes such as mode of birth, neonatal admission, and duration of the active second stage of labour, the committee concluded that evidence on cost-effectiveness was inconclusive and that it was reasonable for the recommendations on pushing technique to be based on the clinical evidence and the woman’s choice.

Again, the committee reasoned that any differences in outcomes were likely to be the principal driver of costs associated with the length of delay in pushing and that any delay thought to produce a clinical benefit was likely to be cost-effective. The recommendations made by the committee reflected current practice and are not expected to have a significant resource impact on the NHS.

Other factors the committee took into account

The committee were aware that defining delay in the second stage of labour needed to take into account the periods of delayed pushing, and so cross-checked these recommendations with the section of the guideline on defining delay, to ensure consistency.

Excluded effectiveness studies

Excluded economic studies