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FAQs on OASI2

Frequently asked questions about OASI2 for women and healthcare professionals

For women

 

For healthcare professionals

Hands on and Manual Perineal Protection (MPP)

Modes of birth

Episiotomies

Diagnosis and systematic perineal examination, including vaginal and rectal examinations

Women and the care bundle

 

For women

What are perineal tears?

Your perineum is the area between your vaginal opening and back passage (anus). It is common for the perineum to tear to some extent during childbirth. Tears can also occur inside the vagina or other parts of the vulva, including the labia. Up to 9 in every 10 first time mothers who have a vaginal birth will experience some sort of tear, graze or episiotomy. It is slightly less common for mothers who have had a vaginal birth before.

For most women, these tears are minor and heal quickly. They are very unlikely to cause long-term problems, but they can be very sore. For more information on minor tears, please visit the RCOG Tears hub.

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What is an OASI?

For some women, a tear may be deeper and extend to the muscle that controls the anus (the anal sphincter).

Third- or fourth-degree tears, also known as an obstetric anal sphincter injury (OASI), can occur in 6 out of 100 births (6%) for first time mothers and less than 2 in 100 births (2%) of births for women who have had a vaginal birth before.

A rectal buttonhole is a rare injury that occurs when the anal sphincter does not tear, but there is a hole between the back passage and the vagina. This means that wind and faeces may be passed through the vagina instead of via the anus. For more information on reducing your risk and recovering from an OASI, please visit the RCOG Tears hub.

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What is a care bundle?

The US Institute for Healthcare Improvement (IHI) originally developed care bundles to describe a collection of interventions needed to effectively and safely care for patients. They define a care bundle as a small set of evidence-based interventions for a defined patient segment or population and care setting which, when implemented together, will result in significantly better outcomes than when implemented individually. 

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What is the OASI Care Bundle? 

The OASI Care Bundle consists of four interventions that should be used together in order to reduce the risk of severe perineal tearing:

  1. In the antenatal period, the midwife or doctor will discuss OASI with the woman and what can be done to reduce the risk of it occurring.
  2. At the time of birth and with the woman’s consent, the midwife or doctor will use their hands to support both the perineum and baby’s head (known as manual perineal protection, or MPP) while communicating with the woman to encourage a slow and guided birth.
    1. For spontaneous vaginal births, MPP should be used unless the woman’s chosen birth position (i.e. water births) doesn’t enable MPP to be used or she declines this technique.
    2. For assisted vaginal births (i.e. forceps, ventouse), MPP should always be used unless the woman declines this technique.
  3. If clinically indicated and with the woman’s consent, an episiotomy (a cut made through the vaginal wall and perineum) should be performed at an angle of 60 degrees from the midline at crowning.
  4. Following all vaginal births, a systematic examination of the vagina and ano-rectum should be offered to all women even if the perineum appears intact. This is to ensure that any tears are identified immediately and that treatment options are discussed and implemented as necessary.

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Why is it important that all 4 components of the OASI Care Bundle are used?

A care bundle is a small set of evidence-based interventions that, when implemented together, will result in better outcomes than when implemented individually. It is therefore important that all 4 elements of the care bundle are used consistently for eligible births, provided that the woman has had the opportunity to discuss the care bundle with the provider during antenatal care and has given her consent to its use during her birth.

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How was the OASI Care Bundle developed and who was involved?

A systematic review of intrapartum interventions used to reduce the rate of OASI took place. This process involved taking data from randomised controlled trials (RCTs) using comprehensive search strategies within academic research databases. These included EMBASE, Ovid MEDLINE, the Cochrane Library, the Maternity and Infant Care database and CINAHL. Then, a review of the non-RCT literature was carried out to identify studies that looked at the effect of various interventions on OASI rates. The results from these reviews were presented to the OASI Care Bundle project team – a group of clinical experts – for consideration in the final care bundle, with the selected interventions chosen on the basis of consensus among the team.

The OASI Care Bundle project incorporated patient and public involvement throughout the inception, implementation and evaluation stages to ensure that care bundle development and implementation were informed by the perspectives of women. The project was supported throughout by an Independent Advisory Group that included two lay representatives. The antenatal information sheet (first component of the OASI Care Bundle) was developed together with women’s groups to ensure that the material was appropriate, whereas lay representatives were present at all skills development days for clinicians.

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How does the OASI Care Bundle differ from other projects such as PEACHES?

The PEACHES programme was initially developed at St Thomas' Hospital in London in 2015. PEACHES stands for:

  • P = Position
  • E = Extra midwife (present at birth)
  • A = Assess the perineum (throughout)
  • C = Communication
  • H = Hands-on technique
  • E = Episiotomy if required
  • S = S-L-O-W-L-Y

There are similarities between PEACHES and the OASI Care Bundle. The differences are that the OASI Care Bundle recommends an extra midwife at birth but does not require it. The position, assessment, communication and ‘slowly’ elements are incorporated into the OASI Care Bundle rather than being individual elements. Finally, the OASI Care Bundle places emphasis on diagnosis, through the systematic examination of the vagina and ano-rectum (back passage).

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Where has the OASI Care Bundle been used and what impact has it had?

The OASI Care Bundle project (hereafter referred to as OASI1) was funded by the Health Foundation in 2016 and implemented in 16 maternity units across England, Scotland and Wales from January 2017 to April 2018. The results of the project were published in the BJOG, BMJ Open and IUJ journals and are freely available to download.

The OASI1 project evaluated 55,000 live singleton vaginal births across the 16 participating maternity units and showed that through adoption of the care bundle, overall OASI rates were reduced from 3.3% before the project started to 3.0% upon its conclusion. There was shown to be no rise in caesarean section or episiotomy rates through use of the care bundle. Using data modelling that takes into account case mix factors such as women’s age, ethnicity and body mass index, the estimated risk of sustaining an OASI was reduced by 20% when the care bundle was used.

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What is the OASI2 project and how is it different to the first OASI Care Bundle project?

Because the OASI1 project was successful in reducing OASI rates in spontaneous vaginal births, the Project Team was awarded additional funding from the Health Foundation in 2019 to scale up the initiative to more maternity units. This second project, “OASI2”, will run from April 2021 to May 2022. It will take place in 10 of the original sites that participated in OASI1, in addition to 20 other maternity units that haven’t been involved until now. OASI2 aims to assess how the care bundle can be introduced in maternity units with different levels of support to implement the care bundle, while continuing to achieve further reductions in OASI rates in a way that is acceptable to women giving birth. For more information on the OASI2 project, please see What is OASI2?.

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Does the care bundle work?

The care bundle was initially piloted in two units, and then rolled out to 16 maternity units as part of OASI1. The end-of-project evaluation showed that the risk of an OASI occurring was reduced by 20% through implementation of the care bundle, with no corresponding rise in caesarean births or episiotomy rates. Furthermore, the interviews and focus groups undertaken as part of the evaluation demonstrated that the OASI Care Bundle was both acceptable and feasible to women and healthcare professionals. You can read the full results of the OASI1 evaluation by downloading the open access articles published by BJOG, BMJ Open and IUJ.

Now, with additional funding from the Health Foundation, we are scaling up the programme to a further 20 sites and will be working closely with them to evaluate the most effective means of supporting adoption of the care bundle while continuing to reduce OASI rates. The rollout of the care bundle during OASI2 will commence in April 2021 and will finish in May 2022. The results will then be evaluated and made public when the project finishes in August 2022. The formal evaluation papers will then be drafted and submitted to academic journals for publication at a later date.

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Will the care bundle change perineal outcomes for women?

The aim of the OASI Care Bundle is to reduce the risk of women experiencing third- or fourth-degree perineal tears during vaginal birth. The evidence from OASI1 showed that use of the care bundle in participating maternity units did lead to an overall decrease in the number of women experiencing severe perineal tears. Therefore, if we continue to see a decline in OASI rates during OASI2, there will exist strong evidence to suggest that use of the care bundle can improve perineal outcomes for women in childbirth.

The OASI2 project will ‘scale up’ the care bundle to a further 20 sites in England, Scotland and Wales, alongside sustaining the bundle in 10 of the original sites that participated in OASI1. In these maternity units, we will evaluate how different implementation strategies impact (1) clinicians’ adoption of the care bundle and (2) the care bundle’s effectiveness in reducing OASI rates. OASI2 will also continue to evaluate the care bundle’s feasibility and acceptability to both women and healthcare professionals. Upon conclusion of OASI2, we will assess whether the implementation strategies tested can be recommended for the care bundle’s scale-up at the national level.

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Will the care bundle affect my birth choices?

No. Both OASI1 and OASI2 projects respect and support women’s choices about how they wish to give birth. A key element of the care bundle involves ensuring healthcare professionals understand the importance of discussing women’s birth choices, particularly choices around birth position. Informed choice requires these discussions to also include the risks and benefits of birth choices in an unbiased and balanced way so women can make the decisions that are right for them. 

The OASI Care Bundle is in no way prescribing a woman’s position for birth or in any way recommending restricting her movement during birth. The aim is to evaluate how perineal trauma can be avoided. Healthcare professionals should use evidence to support and advise women about their choice of birth position. The care bundle interventions can be used with women in most positions. Ultimately, the choice is always the woman’s, armed with the best available information and support.

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How are women involved in the project?

Improving birth outcomes for women is at the heart of both the OASI1 and OASI2 projects. Beyond the women in the study who are giving birth in participating units, women are also involved in discussions and decision-making around the care bundle including in the design, governance and steering of the OASI2 project. The project’s Independent Advisory Group (IAG) membership includes women with lived experience of OASI who inform and input into all project developments. The IAG has further representation from women’s advocacy organisations including the Birth Trauma Association and the MASIC Foundation, while the Project Team also seeks advice and input from members of the RCOG Women’s Network.

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For healthcare professionals

Can warm compresses be used?

As seen in the Cochrane Review (Aasheim et al – see below) there is evidence to suggest that warm compresses reduce perineal tearing. This effect was noted during the development of the care bundle, as similar evidence existed at that time. However, warm compresses were not included in the OASI Care Bundle because there is a lack of clarity over the methods of use and wide variation in practice. For example, whether the compress is held in place continuously, what is used for the compress, at what temperature, and when it is re-heated. The OASI Care Bundle aimed for a set of interventions to be applied consistently every time and so it was decided that the difficulty in ensuring standardisation of warm compress use made it unfeasible to include as a component of the care bundle. However, we recommend that those midwives/doctors who use warm compresses as part of their practice continue to do so. We recommend that warm compresses are used up until the point that MPP should be carried out to ensure adequate visualisation of the perineum.

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Are breech births eligible for use of the OASI Care Bundle?

Vaginal breech births are not eligible for the care bundle. Women with vaginal breech should be cared for in line with RCOG guideline Management of Breech Presentation (Green-top Guideline No. 20b).

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What are the project team’s thoughts on the updated Cochrane review – Aaseheim et al.’s ‘Perineal techniques during the second stage of labour for reducing perineal trauma’?

The updated review contains 22 trials (randomised and quasi-randomised controlled trials) which includes 12 new trials and two previously excluded trials. Included trials have various primary outcomes including: Perineal trauma requiring suturing, frequency of perineal trauma, perineal pain, need for episiotomy and severity of perineal trauma.

In terms of hands on vs. hands off/poised there were two additional studies included in the review: Foroughipour (2011) and Rezaei (2014), both of which reported that perineal trauma was slightly reduced in the hands off group. However, Cochrane has graded this evidence as low quality as the treatment effect is not clear and there was substantial heterogeneity. It is noted that it is very hard to ensure that practitioners fully comply with hands off as they are able to use their clinical judgement and intervene when they feel it necessary. Additionally, as found in the 2011 review, the authors note that the terms hands on, hands off and perineal support all mean very different things in all the included studies.  Similarly, that the hands on techniques are poorly described.

In terms of warm compresses, four studies are included. Use of warm compresses were found to reduce the average number of OASI and this is graded as moderate quality.

All in all, the update review states that ‘the overall conclusions have not changed’ and that further research is needed to evaluate perineal techniques. The need to collect information on women’s views is also highlighted – the OASI Care Bundle project sought to address both of these and you can read our conclusions in the project’s recently published evaluation papers in BJOG, BMJ Open and IUJ.

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Hands on and Manual Perineal Protection (MPP)

My normal practice is to be hands poised, why should I change this?

Evidence from Scandinavia has shown that using manual perineal protection can reduce the incidence of OASI. This, in combination with the other elements of the care bundle, has been shown to reduce the rates of OASI. If a woman chooses not to have manual perineal protection, her choice should of course be respected, but the birth will not be counted as part of the care bundle for statistical purposes. 

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My normal practice is hands on. What is different about MPP and do I still need training?

During the first OASI Care Bundle project, a manual perineal protection technique was taught. Participating units were asked to consistently use this technique as one of the 4 evidence-based interventions that make up the care bundle. This MPP technique will remain part of the care bundle during the OASI2 project, due to commence in spring 2021. If your practice is already hands on, you will still need to seek training in the care bundle to ensure that your technique is consistent with that being used as part of the bundle.

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Why is MPP part of the OASI Care Bundle when the HOOP trial showed that hands on showed no improvement for perineal outcomes?

The findings of the HOOP trial have often been interpreted as suggesting that the hands on approach, adopted by many midwives, did not have an impact in preventing perineal trauma. The HOOP trial studied the effect of hands on vs. hands poised during birth on perineal pain, rather than perineal trauma. It is therefore not a reliable source of evidence by which to base decisions to practice hands on or hands poised in relation to reducing incidence of, and severity of, perineal tears. It should be noted that the trial did find a statistically significant reduction in the incidence of perineal pain experienced by women in the hands on group vs. the hands poised group.

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I don’t feel comfortable performing MPP when a woman is on all fours/standing. Should I ask that she moves position?

No, women must be able to birth in a position of their choice. The care bundle includes training in MPP with the woman in different positions to facilitate this, for instance all-fours and left lateral (side). However, there are some positions where it will not be practical or possible to perform MPP (water births or when the woman is standing, for example). If a woman’s chosen birth position does not enable the use of MPP, her choice should be respected and supported.

If the healthcare professional thinks that a woman is at a particularly higher risk for severe perineal trauma, they should discuss this concern with the woman during antenatal care and suggest some positions above others that allow a good visualisation of their perineum and a slow and controlled birth. MPP is only used once the perineum begins to thin, so all the benefits of mobilising and staying upright in the second stage of labour still apply.

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If the students I mentor are taught hands off at university, what should I do?

For the sites that participated in OASI1 and for those that will be part of OASI2, the aim is for all midwives and obstetricians (including students) to be trained in and use MPP. If a student has not been taught to practice hands on, they should be advised to approach either of their two local champions for training. The local champions will explain the rationale and evidence for the use of MPP. The student will be asked to practice the technique consistently during their time in the unit.

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Will using the MPP technique create discomfort in my hands and wrists?

When done correctly, the MPP technique should not cause any discomfort. The technique is only used for a short period, during the birth of the baby’s head and shoulders. If you do find that you are experiencing discomfort, with the woman’s permission ask for a colleague or one of your local champions to observe your next birth to see how your technique or positioning might be able to be adjusted.

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Modes of birth

Is the care bundle tailored according to mode of birth, i.e. spontaneous vaginal or operative vaginal

Yes. The care bundle is focused on all vaginal births to reduce the incidence of OASI.  Although the same elements of the bundle apply to all women who give birth vaginally, the technique for manual perineal protection will differ depending on whether the birth is spontaneous or an operative vaginal birth (e.g. forceps or vacuum), and depending on the birth position of the woman.

Furthermore, an episiotomy (at 60 degrees at crowning) will only be done when clinically indicated. (The project excludes the management and prevention of OASI resulting from gynaecological/urological procedures. It also excludes considerations on repair techniques and related co-morbidities).

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Episiotomies

When is an episiotomy required?

We appreciate that some midwives rarely carry out episiotomies, but it is important that they feel comfortable doing one should the situation arise.

When indicated, a mediolateral episiotomy should be performed at a 60-degree angle to the midline at crowning. In the context of this care bundle, episiotomy is indicated in cases of fetal distress, delays during the second stage of labour, operative vaginal birth (in accordance to the RCOG guidance Assisted Vaginal Birth (Green-top Guideline No. 26)), and in cases when a severe perineal tear is judged to be imminent – feel digitally for remaining space/stretch and observe whether blood flow to the perineum appears significantly reduced.

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Why have you chosen to teach episiotomies at a 60-degree angle at crowning?

The aim is for the sutured episiotomy to be at 45 degrees from the midline after birth.  For this to happen the episiotomy needs to be performed at an angle of 60 degrees from the midline at the point of crowning of the head. Research has shown that using mediolateral episiotomy when required, at an angle of 60 degrees from the midline at crowning, significantly reduces the chance of anal sphincter injury. There is evidence that when the episiotomy is done at 45 degrees at crowning it measures at 22.5 degrees after birth.

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Are Episcissors-60 part of the project?

No, Episcissors-60 are not part of the project. However, for those units who do use them they may help with episiotomies being done consistently at 60 degrees at crowning (midwives and obstetricians may find them easier to use than normal scissors).

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I am concerned that the OASI Care Bundle will greatly increase the episiotomy rate in our hospital

During OASI1, the Project Team monitored each hospital’s episiotomy rates on a weekly basis throughout the implementation phase to ensure that they did not increase. Episiotomy rates did not increase throughout the project, which was reflected in the findings from the final evaluation of the clinical outcomes that were published in BJOG. The Project Team will continue to monitor episiotomy rates in the same way during OASI2. Episiotomies should never be a ‘routine’ intervention to reduce the risk of OASI and should only be carried out after clinical assessment of the fetal and maternal risks, full discussion with the woman and informed consent given. The indication for an episiotomy should be recorded in the woman’s notes.

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Diagnosis and systematic perineal examination, including vaginal and rectal examinations

Why is systematic perineal examination required after birth?

All women having a vaginal birth are at risk of sustaining an OASI, the presence of which may not be immediately obvious after birth. As such, all women must be offered a systematic perineal examination including the vagina and rectum (back passage) to check for the presence of tears.

The rectal examination involves a midwife or doctor inserting a lubricated index finger into the rectum, and although this should not be painful, it may feel uncomfortable to the woman. A rectal examination is done to assess whether there has been any damage to the external or internal anal sphincter. Information about the benefits and risks of rectal examinations must be given to women prior to the examination to ensure that women are able to give their informed consent.

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Why does the OASI Care Bundle recommend that perineal examinations are conducted even when the perineum appears intact? 

Anal sphincter injury after vaginal birth is not always immediately obvious and can occur even in presence of an intact perineum.  We hope to ensure that no third- or fourth-degree tears, including button hole tears, are left undetected. Therefore, it is recommended that all women who give birth vaginally should be offered a rectal examination after birth to ensure the integrity of the anal sphincter muscles. This also ensures that all tears, including those above the sphincter and involving the rectal mucosa, are diagnosed. Failure to diagnose a third- or fourth-degree tear is regarded as negligent and the potential long-term impact on women’s health and wellbeing can be devastating. Damage to the anal sphincter must be ruled out for every woman who has a vaginal birth. Failure to do this is the leading cause of negligence claims among women who present with ‘missed’ third or fourth degree tears. If the woman does not consent to the rectal examination, this should be recorded in her medical notes to evidence in the future, if needed, with regards to claims of negligence. Midwives and doctors at participating units will be trained in doing rectal examinations to ensure that these are carried out in a consistent manner and with the high level of knowledge of the anatomy needed.

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Will we see more labial and urethral tears as a result of implementing the care bundle?

The project team was not able to analyse any secondary effects on anterior tears during the first phase of the project due to incompleteness of the anterior tears data collected. However, for OASI2, the project team has refined the data specification and will work with participating units to capture this data so that we can evaluate whether use of the care bundle has any impact on these types of tears.

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Women and the care bundle

How do I know if the woman has been informed about the care bundle?

It is crucial that women giving birth in participating units know about the care bundle and what it means for them so they can share any concerns or decline if they do not want to be part of the study. Healthcare professionals should have discussions with all women about their risks of perineal trauma and the OASI Care Bundle at their 32-36 week antenatal appointment when speaking about her birth plan. This discussion should be documented in her notes. It is not sufficient simply to include a leaflet about OASI with other information: healthcare professionals must discuss both OASI and the care bundle with women and provide the opportunity to ask questions. If possible, the care bundle should be discussed again when she is in labour. If severe perineal tearing and the OASI Care Bundle are not discussed with the woman in the antenatal period, her birth will not be compliant with the care bundle. If women decline all or any elements of the care bundle at any point, their choice should, of course, be respected and supported.

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Do women need to give consent to receive the care bundle?

Yes. Women should always be provided with sufficient, unbiased information that enables them to make informed choices about their care. The first of the four interventions of the care bundle is discussing with women their risks of OASI and about the care bundle. When they are discussing their birth plan at 32-36 weeks, the care bundle should be explained and, if it is acceptable to the woman, it should be used. If the woman objects to any elements, this should be recorded in her patient notes. It is important to communicate with women throughout their pregnancy and birth so that they can make informed decisions. The care bundle brings together evidence-based practices and therefore should not pose any adverse risks to women.If women decline all or any elements of the care bundle at any point, their choice should, of course, be respected and supported.

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Will the project restrict women’s choices, discourage water births or birth positions where perineal protection cannot be used?

No. Both OASI1 and OASI2 projects respect and support women’s choices about how they wish to give birth. A key element of the project involves ensuring healthcare professionals understand the importance of discussing and understanding women’s birth choices, particularly choices around birth position. Informed choice requires these discussions to also include the risks and benefits of birth choices in an unbiased and balanced way so she can make the decisions that are right for her. 

The OASI Care Bundle is in no way prescribing a woman’s position for birth or in any way recommending restricting her movement during birth. The aim is to evaluate how perineal trauma can be avoided. Healthcare professionals should use evidence to support and advise women about their choice of birth position. The care bundle interventions can be used with women in most positions. Ultimately, the choice is always the woman’s, armed with the best available information and support.

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