A new Cochrane review has been published on the subject of reducing perineal trauma by using certain techniques during the second stage of labour. This is a controversial topic and I know that this is going to be of interest to a lot of people, as we have been receiving a number of emails from employed midwives who are concerned that they are being forced to use techniques which they do not believe are the best for the women and babies in their care.
One of the problems these midwives face is that the organisations behind such techniques claim that they are evidence-based, and yet it would appear that, in some circles, the phrase evidence-based simply means that, ‘we have been able to find a reference which supports what we think is best’. The Cochrane review includes only the findings of clinical trials and so, while I would be the first to argue that we need other forms of knowledge in addition to that which is derived from clinical trials, the Cochrane summaries are a great starting point and a key source of information on the evidence that is contained in randomised controlled trials of this area, alongside which the authors always let us know whether they consider the trials to be of low, moderate or high quality.
The review authors’ findings are that,
“Moderate-quality evidence suggests that warm compresses, and massage, may reduce third- and fourth-degree tears but the impact of these techniques on other outcomes was unclear or inconsistent. Poor-quality evidence suggests hands-off techniques may reduce episiotomy, but this technique had no clear impact on other outcomes. There were insufficient data to show whether other perineal techniques result in improved outcomes.
Further research could be performed evaluating perineal techniques, warm compresses and massage, and how different types of oil used during massage affect women and their babies. It is important for any future research to collect information on women’s views.” (Aasheim et al 2017)
I suspect that many readers of this blog will also be interested in the breakdown of the different techniques that the review authors considered, so here they are:
Hands off (or poised) compared to hands on
Using ‘hands off’ the perineum resulted in fewer women having an episiotomy (low-quality evidence), but made no difference to numbers of women with no tears (moderate-quality evidence), first-degree tears (low-quality evidence), second-degree tears (low-quality evidence), or third- or fourth-degree tears (very low-quality evidence). There were considerable unexplained differences in results between the four studies. None of the studies provided data on the number of tears requiring suturing.
Warm compresses versus control (hands off or no warm compress)
Fewer women in the warm-compress group experienced third- or fourth-degree tears (moderate-quality evidence). A warm compress did not affect numbers of women with intact perineum (moderate-quality evidence), tears requiring suturing (very low-quality evidence), second-degree tears (very low-quality evidence), or episiotomies (low-quality evidence). It is uncertain whether warm compresses increase or reduce the incidence of first-degree tears (very low-quality evidence).
Massage versus control (hands off or routine care)
There were more women with an intact perineum in the perineal massage group (low-quality evidence), and fewer women with third- or fourth-degree tears (moderate-quality evidence). Massage did not appear to make a difference to women with perineal trauma requiring suturing (very low-quality evidence), first-degree tears (very low-quality evidence), second-degree tears (very low-quality evidence), or episiotomies (very low-quality evidence).
Ritgen’s manoeuvre versus standard care
One small study found that women who had Ritgen’s manoeuvre had fewer first-degree tears (very low-quality evidence), but more second-degree tears (very low-quality evidence). There was no difference between groups in terms of the number of third- or fourth-degree tears, or episiotomies (both low-quality evidence).
The ongoing message from the Cochrane reviewers is that we don’t have enough evidence and so more research is required. Those who are asking how to challenge the introduction of routine interventions which they do not believe to be in the best interests of women and babies may find this a useful reference. We can at least keep pointing out that this is a complex area which needs better evaluation before widespread change is introduced.