The BUMPES study

By The Epidural and Position Trial Collaborative Group on 24 November 2017 Midwives Magazine Labour Study

The Epidural and Position Trial Collaborative Group answer questions about their study.

What was the BUMPES study?

The BUMPES study (Birth in Upright Maternal Position versus lying-down position, in women with a low-dose Epidural, in the Second stage of labour)
was a randomised controlled trial (RCT) designed to find out if the position adopted by nulliparous women with epidural analgesia during the second stage of labour makes a difference to their chance of having a spontaneous vaginal birth. The study team included midwives, lay representatives, obstetricians and anaesthetists as well as trial methodologists and statisticians. 

Why was the study needed?

We knew from a previous Cochrane review (Anim-Somuah et al, 2011) that epidural analgesia prolongs the second stage of labour and makes it more likely that women have an instrumental birth. This review mostly included older studies in which women had received more ‘dense’ epidural analgesia. However, even using low-dose epidural analgesia solutions, as is the norm nowadays, women are still more likely to have an instrumental birth (Comparative Obstetric Mobile Epidural Trial Study Group UK, 2001). Before BUMPES, we really didn’t know if it was better to encourage nulliparous women with low-dose epidural analgesia to be in an upright position during the second stage of labour or in a lying-down position. An RCT was designed and funded by the National Institute for Health Research to answer this clinical question.

Who took part in the study?

All the women who consented to take part in the BUMPES study were 16 years or older, nulliparous, at term, with a singleton, cephalic-presenting baby. A total of 3236 women were randomised, and 41 UK hospitals took part in the trial between October 2010 and January 2014.

How was the study carried out?

As BUMPES was an RCT, women were randomly allocated either to be in an upright position in the second stage of labour, or a lying-down position. Women were randomised once the onset of the second stage of labour was confirmed by their midwife. If a woman found the position she had been allocated uncomfortable, or she needed to be in a certain position for clinical reasons, she was, of course, free to change her position.

Women who were allocated to an upright position could sit straight up in bed or on a chair, kneel, stand or sometimes, if the woman was able to, walk about. Women who were allocated to a lying-down position could lie on either side, supported by a pillow. The study collected lots of information on participants’ labours and births, including how long the second stage of labour lasted and the mode of birth. Other important maternal and neonatal outcome data were collected, both immediately after birth and a year later through a questionnaire.

What were the findings of the study?

Data from 3093 women who completed the study were analysed. The main study finding was that women in the lying-down group were significantly more likely to have had spontaneous vaginal birth. 

In the lying-down group, 41.1% (632/1537 women) had a spontaneous vaginal birth. In the upright group, 35.2% (548/1556) had a spontaneous vaginal birth.

Women’s satisfaction with their care in labour was similar across the two groups. Most women were satisfied with their overall birth experience and more than 85% of women in both groups were satisfied with their position during the second stage of labour. In both groups, around a third of women felt they were not able to move around as much as they wanted. 

To what extent did women stay in their allocated positions?

Every 15 minutes throughout the second stage of labour, midwives recorded the position women were in. Information provided by women about their position in labour confirmed the data recorded by midwives, with 75.8% (794/1047) of women in the upright group stating that they were mostly in the upright position during the passive stage, and 72.3% (752/1040) of women in the lying-down group stating they were mostly lying down during this stage. In the active stage, 72.5% (745/1028) of women in the upright group recalled being mostly upright, and 63.7% (652/1024) of women in the lying-down group recalled mostly lying down.

Were there other differences in the outcomes between the groups?

No advantages to the upright position were found. Some adverse birth outcomes, including severe perineal trauma and haemorrhage, were more common among women in the upright group. In line with good statistical practice, all secondary outcomes were tested at the more stringent 1% level. None of the secondary outcomes, including physical and psychological health of the women and their babies, either in the short term or one year later, met levels of statistical significance.   

What does the BUMPES study mean for midwifery practice?

There is now clear evidence that nulliparous women who have a low-dose epidural in labour are more likely to have a spontaneous vaginal birth if they lie down on their side in the second stage of labour. Midwives should now encourage such women to consider using this position, provided that they are comfortable. 

How do I know if the epidural given to a woman is low-dose?

It is now normal to use a low dose, but if there is any uncertainty over the dose of the epidural solution that has been used, just ask the administering anaesthetist. 

What if a woman wants to move or is uncomfortable on her side? 

The results of the BUMPES study do not mean that women with epidural analgesia should be persuaded against their wishes to use a lying-down position in the second stage of labour. Women should always be free to choose whichever position they prefer and helped to find the position that feels best for them. As midwives, we need to be aware that only half the women in both groups reported being able to move as much as they wanted. Women’s movement may have been limited by intravenous infusions and fetal monitoring as well as their epidural, but this is an aspect of care that we should try and improve on.

Do the BUMPES results apply to women without an epidural, or if they are multiparous?

The results apply to nulliparous women in the second stage of labour with epidural analgesia. It is unclear if the same findings would be found for multiparous women in labour with an epidural. However, all women with epidural analgesia should be offered the choice of adopting a lying-down position in the second stage until evidence suggests this is not beneficial.

Many midwives would have expected the women in the upright group to do better. What’s happening to make lying down better?

The results were unexpected. What BUMPES tells us is just how much we still need to find out about the normal physiology of birth, and how this is affected by epidural analgesia. It could be that being upright with epidural analgesia leads to pelvic and perineal congestion. Maybe the upright woman with epidural analgesia has more difficulty pushing her baby past her coccyx, or it has been suggested that the blood flow to the uterus is better with the woman on her side, leading to stronger contractions. 

Although BUMPES found the lying-down position to be better for women, we need to remember that the proportions of women having a spontaneous vaginal birth were low in both groups. In the lying-down group, although better than the upright group, only 41% of women had a spontaneous birth. 

Clearly, we need more work and research to improve outcomes for nulliparous women who choose epidural analgesia in labour, but for now midwives can increase a woman’s chances of a spontaneous birth by putting the BUMPES results into practice. 

Should midwives encourage nulliparous women with epidural analgesia to lie on their side during all of the second stage of labour?

Yes. Midwives need to inform women about the BUMPES trial results and should encourage and support women to adopt a lying-down position in the passive and active second stage. The BUMPES study is the largest and most recent study and its results can help women make a choice about their position in the second stage of labour if they have epidural analgesia. (Please see image at the top of the page. But please note that women should be encouraged to lie on either their left- or right-hand side, whichever they feel is more comfortable.

How can I read the full BUMPES paper?

The full study paper has been published in the British Medical Journal and is freely available to download at bmj.com/content/359/bmj.j4471.full

For more information, contact Peter Brocklehurst of the Epidural and Position Trial Collaborative Group at [email protected]

Top