The use of water during childbirth – MIDIRS

Since the early 1980s use of immersion in water during labour and birth has been increasingly promoted to enable women to relax, help them cope with pain, and maximise their feelings of control and satisfaction1-4.

In 1992 the House of Commons Health Committee recommended all hospitals provide the option of a birthing pool where practicable5. Currently few women give birth in water but the option of immersion or showering during the first stage of labour is commonly available.6-8

Although problems have arise which have been attributed to water use, the results of the most formal evaluations have not clearly associated water use with harmful outcomes for mother or baby 3,9-13.

The lack of robust evidence of harm or benefit means that childbearing women and health practitioners alike are subject to conflicting opinion about the usefulness and safest of water, particularly for birth.

However, a recent observational study over a nine year period concluded that ‘waterbirth was associated with low risks where obstetric guidelines were followed’16.

At present in the UK there is no reliable measurement of the rate of birth in water.
A national survey of maternity units in the UK in 2002 found that 63% (216/342) had a birthing pool8; 67% (228/342) reported having at least one midwife trained to provide support for women giving birth in water and 36% (121/342) said that at least half of the midwives working in their unit were trained to support birth in water.

How is water used during labour?

Water use ranges from informal, for example when a woman in early labour decides to get into her bath at home before going to hospital, to formal use in a specially designed birthing pool. Informal use in a domestic bath or shower is often initiated by a woman herself to help her cope at home before her labour is well established.

Formal use implies either that a woman has actively chosen to use water as part of her plan for labour and/or childbirth or that a health professional, usually a midwife, has suggested use during established labour.

Why water use is promoted

Use of immersion in water during childbirth has largely been driven by pregnant and birthing women17 and supported by midwives. During the first stage of labour it is advocated to shorten labour and help a woman relax and cope with contractions, feel more in control, and to reduce intervention by health professionals3,18-21.

During the second stage, proponents use it to allow perineal tissues to stretch spontaneously, birth to occur with minimum intervention, and to provide the baby with a gentler transition into extra-uterine life. Expectant management of the third stage is likely if a woman is in water.

Limitations on water use

Many health professionals consider that water use during the first stage of labour in uncomplicated pregnancy is unlikely to harm the mother or baby22,23, whilst others have concerns about water use at any point in labour14.

Local clinical guidelines may restrict water use to women considered at ‘low’ obstetric risk7, and other aspects of care may be prescribed, for example when and how to monitor the temperature of the water, the degree of cervical dilatation at which to begin its use24, and whether the immersion is considered safe for all stages of labour6,25.

Problems associated with possible risk of infection or cross infection caused by amniotic fluid, blood, and faeces have been described26-28 and some hospitals have restricted use of birthing pools to women who have tested HIV negative during pregnancy29.

However, at a multi-disciplinary consensus meeting held in London in 1996, it was agreed that mandatory HIV testing for prospective users of birthing pools could be an extreme reaction to the perceived risks and that high standards of pool hygiene would be an appropriate way forward30. Local infection control guidelines should cover the use of water pools25,31 and procedures to minimise risk of cross infection13, 32.

It has been suggested that high water temperature can cause serious changes in feto-maternal haemodynamic regulation and fetal thermoregulation33. It has been reported that fetal tachycardia can be reduced by cooling the water34 and most providers and clinical guidelines specify a temperature range within which the water should be maintained during the first and second stage of labour7,35.

The prospect of a woman giving birth in water can cause anxiety about how to deal with unexpected emergencies such as shoulder dystocia, the need to avoid the baby inhaling water, or being unaware that the umbilical cord has been severed11.

Despite the fact that it denies women choice about birth, one response has been to limit water use to first stage only6. Development of agreed clinical protocols to deal with unexpected complications25 and providing training which allows3 staff to achieve relevant competencies is key to enabling real choice for women about use of water.

There are theoretical risks of increased blood loss, retained placenta, or water embolism, and professional advice is often to conduct the third stage out of water25.

Because water adds to the difficulty of estimating blood loss accurately, it has been proposed that blood loss would be more appropriately estimated as being either more or less than 500ml36 and that the overall physical condition of the woman should be used as the most important indicator to assess the impact of any bleeding37.

In summary, although not universally accepted, first stage water use is less controversial than immersion for the second or third stage of labour22,23,38.

The research evidence

The effects of water use during the first stage of labour on maternal and fetal outcomes have been evaluated in several randomised controlled trials4,9,10,12,13,39 with sample sizes ranging from 60 to 123934.

The use of water has been shown to reduce the rate of augmentation40; however, no trial has been large enough to measure the effect of water use on important neonatal outcomes such as perinatal death or other serious neonatal or maternal morbidity.

In addition, there has often been significant cross-over between study groups4,12, reducing the likelihood of identifying clear differences between women allocated to water use and those not.

A systematic review of eight trials41 indicated a statistically significant reduction in the use of pain relief with no such significant difference in the rate of operative deliveries or in neonatal outcomes.

It concluded that while the use of water in the first stage of labour can be of benefit to some women, there is no evidence at present to support or not support a woman’s choice to give birth in water.

Retrospective comparison has been made of women who have used water with those who have not42,43.

However, there are considerable difficulties in interpreting such studies because of the possibility that the results are inherently biased.

In the same way, findings of cohort studies which suggest benefit for water use in terms of pain relief and increased rate of cervical dilatation44-47, or those which indicate differences in rates of maternal and neonatal infection48-50, are also open to criticism.

A recent study16 compared neonatal and maternal morbidity and mortality for spontaneous singleton births that took place in water or on land.

This was an observational study over a nine year period and data were obtained through standardised questionnaires for 9,518 births, of which 3,617 were waterbirths and 5,901 landbirths.

Statistically significant differences were identified between the two groups; women who gave birth using water were less likely to suffer serious perineal trauma, use no analgesia and have a lower blood loss than women in the landbirth group.

Maternal and neonatal infection rates were the same for both groups, but more landbirth babies had neonatal complications requiring transfer to an external NICU.

During the study, there were neither maternal nor neonatal deaths related to spontaneous labor.

The authors acknowledge the potential bias that could arise from the self-selection issue but argue that this is well accounted for in the analysis.They conclude that waterbirths are associated with low risks for both mother and child when obstetrical guidelines are followed.

Another study51 based in a centre for low risk women was a retrospective case review over a five year period of 1355 births in water.

When compared with land births over a corresponding period, women who gave birth in water had significantly fewer episiotomies with no evidence of a corresponding rise in lacerations, a reduction in the length of the first stage of labour, no increase in the risk of acquired infection or aspiration pneumonia and considerably lower levels of analgesia use.

Neonatal condition assessed by arterial cord blood pH, base excess and birth weight showed no differences.The authors conclude that this represents a realistic option for women at low risk of complications.

Many reports about water use are case series1,20,52-62 and focus on perceived benefits of water use for the mother, her baby and birth attendant.

These include shorter labour52, less use of pharmacological analgesics46,53, less intervention by care givers19, lower rate of perineal trauma60-62, and increased satisfaction with the experience of labour and birth54.

By contrast, some case reports have highlighted serious problems such as fetal overheating33,34, neonatal sepsis28, near drowning63 or death64.

Overall, reviews of the evidence21,23,65,66 conclude that appropriately large-scale research is still required to evaluate rigorously the physiological effects13, clinical outcomes, and economic impact of water use.

What we don’t know

The current evidence about water use remains quite heavily dependent on case series and comparison studies that include varying sized samples.

Therefore, reliable evidence about efficacy and effectiveness is still equivocal67.

  • Outstanding issues which require evaluation include:
  •  is water use causally associated with an increase in perinatal mortality or serious perinatal morbidity?
  •  at what dilatation should a woman be advised to begin water use?
  •  does the size or shape of the water container affect outcomes?
  •  if water has an effect on important physical/psychological outcomes for mothers or babies, are there particular women who should avoid using water during labour?
  •  to what extent immersion in water affects the length of labour?

Implications for maternity

Water use during the first stage of labour is offered by the majority of maternity care provider units in the UK and most offer support for water birth8.

Introduction of, and sustained suppor t for, water use may have considerable implications for service governance68.

However, not all costs fall to providers of care; a substantial cost burden is likely to be borne by labouring women themselves during informal use in domestic baths and showers or by hiring specially designed pools for use in their home or in a maternity unit.

Most maternity units have installed a water pool for use in labour8 and although installation and maintenance of a specially designed pool in a maternity unit involves obvious financial cost, this may be offset if there is a reduction in analgesia and anaesthetic use44.

There is evidence that formal water use means that at least one midwife will be in constant attendance during the first stage of labour and that at least two will be in attendance for birth7.

This level of staffing may be difficult to sustain and may have implications for equity of care for women who do not use water22.

Clear strategies for the training, preparation and support of staff who offer use of water during labour are recognised as essential7,25,31,37,44.

Key components of these include clarification of the roles of different maternity health professionals, multi-disciplinary development of local protocols, development of guidelines for clinical practice, and short-term secondment of midwives to learn alongside practitioners skilled and experienced in water use.

Implications for practice

Women may choose to use immersion in water during labour and/or birth. Midwives and other maternity care workers should therefore be knowledgeable about the evidence in terms of potential advantages and disadvantages.

Given the current quality of reliable evidence, effective practice is likely to be informed and influenced substantially by shared experience and personal observation.

Disproportionate weight may therefore be placed on perceived disadvantages or advantages and credibility given to outcomes which may not be associated causally with water use.

Practitioners should be alert to the evolving evidence base which underpins the use of water.

  •  Immersion in water during childbirth is a care option women may wish to choose and which health professionals have a responsibility to discuss and support using clear and balanced information.
  •  As with any labour or birth, it is essential to maintain systematic, contemporaneous records and to monitor and record routine observations about the well-being of the mother and the fetus. These data should be used to audit care and gather information about outcomes.
  •  Water temperature should be measured regularly using a thermometer and recorded.The water temperature should be comfortable for the woman and should be not more than 37°C during the first stage of labour and between 36-37°C in the second stage.
  •  Maternal faeces, meconium and blood clots should be removed from the water using a sieve, and effective cleaning of pools before/after use should be carried out to minimise risk of infection or cross-infection.
  •  Birth in water: the baby should be born fully submerged and be brought gently and without delay to the surface so that he/she can make their first respiratory efforts in air.
  •  Comprehensive, large scale research is required to address questions about the safety and effectiveness of using water during labour and/or birth.

Reproduced from Midirs 2005, last revised Jan 2005, review date Jan 2007. Informed Choice is supported by the Royal College of Midwives and the National Childbirth Trust.

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Cochrane Review – Immersion in water

Background

Enthusiasts suggest that labouring in water and waterbirth increase maternal relaxation, reduce analgesia requirements and promote a midwifery model of care. Sceptics cite the possibility of neonatal water inhalation and maternal/neonatal infection.

Objectives

To assess the evidence from randomised controlled trials about immersion in water during labour and waterbirth on maternal, fetal, neonatal and caregiver outcomes.
Search strategy

We searched the Cochrane Pregnancy and Childbirth Group’s Trials Register (October 2008).

Selection criteria

Randomised controlled trials comparing any bath tub/pool with no immersion during labour and/or birth.

Data collection and analysis

We assessed trial eligibility and quality and extracted data independently. One review author entered data and another checked for accuracy.

Main results

This review includes 11 trials (3146 women); eight related to the first stage of labour, one to the first and second stages, one to early versus late immersion in the first stage of labour, and another to the
second stage.

We identified no trials evaluating different baths/ pools, or the management of third stage of labour.

Results for the first stage of labour showed there was a significant reduction in the epidural/spinal/paracervical analgesia/anaesthesia rate amongst women allocated to water immersion compared to controls (478/1254 versus 529/1245; odds ratio (OR) 0.82, 95% confidence interval (CI) 0.70 to 0.98, six trials).

There was no difference in assisted vaginal deliveries (OR 0.84, 95% CI 0.66 to 1.06, seven trials), caesarean sections (OR 1.23, 95% CI 0.86 to 1.75, eight trials), perineal trauma or maternal infection.

There were no differences for Apgar score less than seven at five minutes (OR 1.59, 95% CI 0.63 to 4.01, five trials), neonatal unit admissions (OR 1.06, 95% CI 0.70 to 1.62, three trials), or neonatal infection rates (OR 2.01, 95% CI 0.50 to 8.07, five trials).

A lack of data for some comparisons prevented robust conclusions. Further research is needed.

Please click here to read the full article

 

 

Randomised controlled trial of labouring in water compared with standard of augmentation for management of dystocia in first stage of labour

Elizabeth R Cluett, lecturer in midwifery1, Ruth M Pickering, senior lecturer in medical statistics2, Kathryn Getliffe, professor of nursing1, Nigel James St George Saunders, medical director3

Objectives

To evaluate the impact of labouring in water during first stage of labour on rates of epidural analgesia and operative delivery in nulliparous women with dystocia.

Design

Randomised controlled trial.

Setting

University teaching hospital in southern England.

Participants

99 nulliparous women with dystocia (cervical dilation rate < 1 cm/hour in active labour) at low risk of complications.

Interventions

Immersion in water in birth pool or standard augmentation for dystocia (amniotomy and intravenous oxytocin).

Main outcome measures

Primary: epidural analgesia and operative delivery rates. Secondary: augmentation rates with amniotomy and oxytocin, length of labour, maternal and neonatal morbidity including infections, maternal pain score, and maternal satisfaction with care.

Results

Women randomised to immersion in water had a lower rate of epidural analgesia than women allocated to augmentation (47% v 66%, relative risk 0.71 (95% confidence interval 0.49 to 1.01), number needed to treat for benefit (NNT) 5).

They showed no difference in rates of operative delivery (49% v 50%, 0.98 (0.65 to 1.47), NNT 98), but significantly fewer received augmentation (71% v 96%, 0.74 (0.59 to 0.88), NNT 4) or any form of obstetric intervention (amniotomy, oxytocin, epidural, or operative delivery) (80% v 98%, 0.81 (0.67 to 0.92), NNT 5).

More neonates of women in the water group were admitted to the neonatal unit (6 v 0, P = 0.013), but there was no difference in Apgar score, infection rates, or umbilical cord pH.

Conclusions Labouring in water under midwifery care may be an option for slow progress in labour, reducing the need for obstetric intervention, and offering an alternative pain management strategy.

Introduction

Slower than expected progress in the first stage of labour (dystocia) occurs in 20% of nulliparous women in labour and accounts for 20% of caesarean sections and 40% of instrumental deliveries, and results in longer hospitalisation.1 For women at low risk of complications, it marks the transition from midwifery to obstetric management.

Since proponents of active management first claimed the benefits of shorter labour and lower rates of caesarean section,2 3 debate has continued over conservative versus aggressive management and the medicalisation of birth.

Management strategies for dystocia vary from immediate augmentation4 5 to delayed intervention up to four hours after diagnosis.6-8 Comparison between strategies is difficult as specific features often differ; for example, one-to-one care is recognised to have beneficial effect on labour outcomes.9

Our current trial was based on two precepts. Firstly, that incomplete understanding of labour may lead to unnecessarily early intervention. Secondly, that anxiety and pain may trigger a stress response,10 leading to reduced uterine activity and dystocia.11

Labouring in water may ameliorate this stress response by aiding relaxation and pain relief. Few trials have evaluated labouring in water, perhaps because of the difficulty in randomising women who may have strong preferences.12

A Cochrane review concluded that, for women at low risk of complications, there was no clear evidence of advantage or disadvantage in using a pool in labour but further research was needed.13 Two national surveys concluded that labour and birth in water had no effect on perinatal mortality.14 15

In preparation for the trial reported here, we conducted a feasibility study comparing labour in water with augmentation and conservative management for women with dystocia,16 but conservative management was considered unacceptable by women and clinicians. Our current trial therefore compares labour in water with augmentation in nulliparous women with dystocia.

Participants and methods

Design

Our randomised controlled trial compared immersion in water during the first stage of labour after diagnosis of dystocia with augmentation, the standard management for dystocia. We conducted the trial between January 1999 and December 2000 in a large university teaching hospital in southern England with about 4500 births a year.

Study population

Nulliparous women with a diagnosis of dystocia (cervical dilation of < 1 cm/hour)—who at that time would routinely have been advised to have their labour augmented by amniotomy or oxytocin infusion, or both—were eligible for the trial if they were able to give informed consent, had received information about the trial during their pregnancy (a leaflet describing the trial was distributed to all nulliparous women antenatally), were in spontaneous, active labour, and were at low risk of complications (full term, singleton pregnancies, fetus in cephalic presentation, and no medical, obstetric, or psychiatric problems).

Intervention

After participating women were randomised, each management option consisted of a package of care provided by midwives, including one-to-one care. Labour progress was assessed by vaginal examinations every four hours and documented on a standard partogram. All women could request any form of analgesia available at any time.

Augmentation—Women in the augmentation group received the standard management for dystocia. Amniotomy was performed if the membranes were intact, and a midwife managed the labour for the next two hours unless otherwise clinically indicated.

If the membranes were already ruptured or progress was not satisfactory during the two hours after amniotomy, intravenous oxytocin was given, starting at 4 mU/min and doubled every 30 minutes, up to a maximum of 64 mU/min, until regular contractions (3-4 every 10 minutes) occurred. Continuous fetal monitoring was carried out.

Labour in water—Women allocated to labour in water used a permanent, acrylic, oval waterbirth pool measuring 154 cm by 184 cm by 77 cm and filled with still tap water without additives so that immersion was to above the breasts when sitting. Water temperature was maintained at 36.0-37.0°C.

The maximum stay in the pool before reassessment by vaginal examination was four hours. If labour progress was satisfactory (cervicaldilation 1cm/hour),subsequent care could continue in the pool if the woman wished, otherwise augmentation was advised.

Sample size

We based our estimate of the potential effect size on an audit of 50 nulliparous women with dystocia in May-July 1997, who would have met the trial inclusion criteria.

We concluded that 220 women would be required to detect an absolute reduction of 25% in the rate of epidural analgesia (from 60% to 35%) and an absolute reduction of 20% in the operative delivery rate (from 40% to 20%) with 90% power in 5% two sided tests.

The local incidence of dystocia in nulliparous women meeting our eligibility criteria was about five a week (260 a year).

In our pilot study we obtained a consent rate of 71%,16 but we anticipated a lower rate when all midwives undertook recruitment, and therefore planned a recruitment period of two years.

Randomisation and recruitment

We used a computer generated randomisation schedule in balanced blocks of 20. Concealment was ensured by an independent person putting allocation details in sequentially numbered, opaque, sealed envelopes.

Ten consecutively numbered envelopes were stored in the labour ward at any one time and audited daily to ensure they were intact.

After dystocia was diagnosed, a midwife who had received training in patient recruitment checked that the woman in question had received the information leaflet about the trial, assessed her eligibility for the study, and, if suitable, sought her informed consent.

When a woman agreed to participate the midwife opened the next trial envelope to allocate the woman to a treatment arm and to give her a unique trial number. Participation in the trial was recorded in the woman’s routine maternity records.

Outcome measures

Primary outcome measures were epidural analgesia and operative delivery (ventouse, forceps, or caesarean section).

Secondary measures included augmentation rates (receiving amniotomy or oxytocin, or both) and maternal or neonatal morbidity (any infection, admission to the neonatal unit, or condition that required medical care up to the 10th postpartum day).

Obstetric data were recorded in the maternity records by practitioners and abstracted after discharge from maternity care.

It was not possible to conceal allocation from clinical practitioners or at the time of data abstraction as care provided was clearly documented. However, as data were objective in nature and recorded contemporaneously observer bias was minimised.

We conducted a postpartum structured interview in the maternity unit to assess retrospectively the women’s experience of pain at 30 minutes after the intervention started and change in pain over the same time period (measured with visual analogue scales of 0 to 100 mm for pain experience and -50 mm to +50 mm for change in pain).

We did not assess pain concurrently because of the disruption to the women and midwives. We also assessed women’s satisfaction overall and in relation to privacy and freedom of movement (asked as separate questions) using four point Likert scales.

We chose to use a structured interview format to reduce potential bias because it was not possible to keep the interviewer blinded to women’s treatments as their comments made the allocation apparent.

Statistical analysis

We analysed results on an intention to treat basis. We compared rates of epidural analgesia and operative delivery between groups using Pearson’s 2 tests and presented results as relative risks with 95% confidence intervals. When numbers were small we calculated exact P values and confidence intervals in StatXact-5.

We produced numbers needed to treat to produce benefit in one woman and calculated confidence intervals as the inverse of the confidence interval about the absolute risk difference.

Confidence intervals around the numbers needed to treat for non-significant differences include the numbers needed to treat to produce harm,17 showing that results are not inconsistent with the intervention producing worse outcome.

We used Mann-Whitney tests to compare length of labour and women’s pain and satisfaction scores, and presented confidence intervals for differences in means.

A confidential summary of the safety data was prepared after 50 women had been randomised, and assessed by an obstetric consultant independent of the trial, who recommended that recruitment continue.

Results

Recruitment

Of 3825 nulliparous women who delivered in the unit during the two years of recruitment, 741 were defined as being at low risk of complications at the time of the diagnosis of dystocia (see figure). Consent was sought from 176 eligible women, of whom 99 (56%) agreed to participate, and were randomised.

The two groups of women showed no important differences in baseline characteristics (table 1). There was good adherence to the trial protocol, with 48 of the 49 women allocated to labour in water using the pool, and 48 of the 50 women allocated to standard care receiving augmentation.

The woman who declined to enter the water requested an amniotomy. Two women in the augmentation group progressed before augmentation could be started.

Primary outcomes

Twenty three women (47%) allocated to labour in water received epidural analgesia after randomisation compared with 33 (66%) in the augmentation group (relative risk 0.71 (95% confidence interval 0.49 to 1.01), number needed to treat 5) (table 2).

The numbers of operative deliveries (caesarean sections and ventouse and forceps deliveries) were similar in both arms of the trial, with 24 (49%) women allocated to labour in water receiving an operative delivery compared with 25 (50%) women allocated to augmentation (relative risk 0.98 (0.65 to 1.47), number needed to treat 98).

Secondary outcomes

Twenty five of the 27 women in the water labour arm who had made slow progress at the assessment four hours after recruitment received augmentation.

A further three women progressed slowly subsequently and also received augmentation. Seven women who progressed satisfactorily received an amniotomy for other indications.

The number of women who received augmentation (amniotomy or oxytocin) in the water labour arm was significantly lower than that in the standard care arm (35 (71%) v 48 (96%), relative risk 0.74 (0.59 to 0.88), number needed to treat 4) (table 2).

The mean duration of the first stage of labour was similar in the two groups, 10.47 hours in the water labour group and 10.26 hours in the augmentation group (table 3).

Women allocated to labour in water reported significantly lower mean pain scores at 30 minutes after start of the allocated management (49 mm v 64 mm) and a reduction in mean pain (-26 mm) compared with an increase for women receiving augmentation (12 mm).

Women allocated to labour in water were more likely to report satisfaction with freedom of movement (91% v 63%) and with experience of privacy (96% v 81%), but there was no difference between groups in overall satisfaction (table 3).

Maternal and neonatal wellbeing

Maternal and neonatal infection rates were similar in the two groups (table 4), as was neonatal condition at birth indicated by Apgar score and umbilical cord pH. Six neonates born to women in the water labour group were admitted to the neonatal unit compared with none in the augmentation group (P = 0.013).

The reasons for admission were: cardiac defects (1), hypothermia (2), fever (1), suspected infection on day 2 (1), and poor feeding on day 3 (1). There was a mean delay of 6 hours (range 2-10 hours) between women leaving the pool and birth.

With the exception of the infant with cardiac defects, all these neonates, who had required an operative delivery, were reunited with their mothers within 48 hours and experienced no subsequent problems.

Discussion

This is the first trial to evaluate the impact of labouring in water for nulliparous women with dystocia. Compared with women given standard augmentation, the women labouring in water had no difference in operative delivery rates and tended to receive less epidural analgesia.

Before this trial it had been suggested that as all the women would have dystocia, augmentation would be inevitable, along with longer labour, and/or assistance in the second stage of labour.

However, almost 30% of women in the water arm did not receive augmentation and 20% received no obstetric intervention, without evidence of longer labour, both of these rates being significantly different from the augmentation arm. In addition, women retrospectively reported less pain and increased satisfaction.

Our findings suggest that delaying augmentation in association with a supportive environment (water immersion) is acceptable to women with dystocia and may reduce the need for epidural analgesia without increasing labour length or operative deliveries.

This is important, as it has been suggested that women prefer earlier intervention.7

Also a management approach that reduces rates of augmentation and associated obstetric intervention may contribute positively to maternal physiological and psychological health: oxytocin infusion is known to increase the risk of uterine hyperstimulation and fetal hypoxia, and obstetric interventions are associated with lower maternal satisfaction.18

A reduced need for epidural analgesia and augmentation may enable staff and other resources to be used differently—for example, allowing more women to receive one-to-one care in labour.

Maternal and neonatal wellbeing

The trial was not large enough to detect differences in maternal and fetal morbidity. However, indicators of wellbeing were similar in the two groups, with the exception of increased admission to the neonatal unit after labour in water.

Possible reasons for this include the water immersion itself, the delay in intervention of up to four hours (even though this did not affect overall labour length), extra caution by practitioners when women were known to have laboured in water, or chance factors with no direct relation to the trial.

No other studies of labour in water have reported such an association: instead, they either did not provide data on admissions to neonatal units19 20 or reported only one admission21 or similar admission rates in both trial arms.22

Eckert et al reported an increased incidence of initial resuscitation measures with water immersion,22 but we found no difference in Apgar scores and blood gas analysis at birth.

Indeed, three of the admissions to the neonatal unit were between nine and 48 hours after delivery, while the three admissions immediately after birth were associated with temperature regulation.

Comparative studies of labour in water found no increase in admissions to neonatal units or other markers of neonatal distress.23-25 It is clearly important to ensure ongoing audit of neonatal outcomes for women who labour in water.

Limitations of study

Only 99 of the intended 220 women were recruited for a variety of reasons. In common with other trials18 epidural analgesia was the main reason why nulliparous women with dystocia were ineligible for our study (28%).

Local rates of epidural analgesia and their likely impact on recruitment should feature as part of the planning of any future trials involving labour management.

In our busy maternity unit recruitment was not a priority, and some eligible women were not invited to participate in our study. The main reason eligible women chose not to enter the trial was a preference for one or other form of care (40%).

This is a recognised problem, and consideration is needed on how this may affect the generalisability of our findings and ways to overcome recruitment problems.

Recruitment became more difficult towards the end of the trial because of the adoption of a more conservative approach to managing dystocia in the unit and the introduction of the modified World Health Organization partogram,6 which incorporates a delay between the identification of slow progress and augmentation.

During this delay midwives could facilitate ongoing conservative management; as a consequence, they were less willing to recruit women to the trial, knowing that half of the women would immediately receive augmentation.

Thus, the trial was not continued past the planned two years. The low recruitment rate contributed to the outcomes achieved, such as the lack of statistical significance in relation to the difference in rates of epidural analgesia.

    • What is already known on this topic

For women in normal labour, immersion in water is associated with less need for analgesia and increased satisfaction

Augmentation of labour, in particular oxytocin administration, is associated with hyperstimulation and decreased maternal satisfaction

    • What this study adds

For nulliparous women with dystocia (cervical dilation < 1 cm/hour), immersion in water for up to four hours seemed to reduce need for augmentation of labour, reduce pain, and increase satisfaction, without increasing overall length of labour or operative delivery rate

Water immersion may be an alternative option to early augmentation of labour

We thank the women who participated in the trial; the midwives and obstetric and support staff of the unit where the trial was conducted; research advisory group members Maggie Elliot and Debbie Gould; and Rona McCandlish for her support in preparing this paper.
Contributors: ERC was principal investigator and research midwife and was responsible for trial design and coordination, and data collection and analysis, supported by RMP and KG as research supervisors. NJS contributed to the initial idea and enabled the trial in the clinical setting.

All authors helped to write the paper. ERC acts as guarantor for the paper.
Funding: Southampton University Hospitals NHS Trust.
Competing interest: None declared.
Ethical approval: Approval was given by the local research ethics committee.

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