These archives contain extracts from discussions held on the UK Midwives and Consumers email list, a discussion group for people interested in midwifery in the UK. Open to midwives, students, mothers, and anyone interested in improving maternity services in UK. Posts in these archives express the views of the individual authors, and not those of the Association of Radical Midwives.
This draft document has been withdrawn by the RCOG following representations by other groups. It is reproduced here for your interest.
The aim of this guideline is to provide a review of information on birth in water and to suggest possible strategies to minimise the potential hazards to mothers and infants which may arise from choosing this type of delivery.
The use of warm water for relaxation and pain relief during early labour has been in practice for many decades, but usually only for brief periods of 20-30 minutes. Only in the early 1990s did it become popular to give birth in water and to use prolonged immersion in water during labour.
Those advocating labour and/or birth in water argue that buoyancy in water helps to relax and the warmth may help to reduce pain experienced in labour. A systematic review comparing labour in water with conventional labour (988 women) found no clear differences in either benefits or adverse effects between the two options. [1] In this review all the women left the water for the birth.
In recent times, birth in water was initially popularised by Odent [2]. By 1990, the Scientific Advisory Committee of the RCOG was sufficiently concerned to produce a statement on birth in water, emphasising the need for scientific study. This statement was revised in 1994, following a period of intense media interest generated by a report of one perinatal death attributed to labouring in warm water.[3] The need for appropriate information about the safety of water births and their level of use throughout the country was again highlighted. Some of this information is now available, and it is timely to review the evidence surrounding birth in water.
A survey of NHS maternity units in England and Wales during 1994-96 concluded that about 0.6% of all deliveries occurred in water during that time, a total of 4,032 births. Of these, 9% (380/4,032) delivered at home.[4]
There are no routine records of the number of women who use prolonged immersion in water during labour but leave the pool for delivery. Anecdotally, this is likely to be a far more common practice than birth in water.
The Cochrane Library and the Cochrane Register of Controlled Trials were searched for relevant RCTs, systematic reviews and meta-analyses. A search of MEDLINE was also carried out.
The definitions of the types of evidence used in this guideline originate from the US Agency for Health Care Policy and Research. Where possible, recommendations are based on, and explicitly linked to, the evidence that supports them. Areas lacking evidence are highlighted and annotated as 'Good Practice Points.'
No trials have compared the effects of being born in water with conventional birth. Many of the possible complications listed here are therefore theoretical risks that are difficult to quantify.
In the national surveillance study of morbidity and mortality among babies delivered in water the perinatal mortality was not different to that associated with a conventional birth.
The British Paediatric Surveillance Unit conducted a survey of babies who had been admitted to special care baby units or who had died following delivery in water between April 1994 and March 1996. The results of this study have recently become available.4 Of the 64 reports, 37 followed delivery in water and 27 involved labour in water with delivery outside the pool. This study provides some information about the frequency of adverse events for the babies severe enough to warrant admission to a special care baby unit.
There were five perinatal deaths among the 4,032 babies born in water in England and Wales, giving a perinatal mortality of 1.2/1000 live births (95% CI 0.4-2.9). This compares with a perinatal mortality of 1.4 (95%, CI 0.7-2.3) for a comparable group of low risk women having a conventional birth (relative risk 0.9, 99% CI 0.2-3.6).
Evidence Level III
The hypothesis is that warm water relaxes the muscles and encourages mental relaxation. This then increases catecholamine release, possibly improving uterine perfusion, relaxation and contraction, thus leading to less painful contractions and shorter labours. Body temperature (37ºC) is the ideal temperature. If the temperature does rise there is a risk of circulatory redistribution to the skin and hypertension, resulting in decreased placental perfusion. Also, sweating would increase, with a risk of dehydration during a long immersion. For the 64 babies identified in the surveillance, no information about temperature was given for 26 (41%). Evidence Level IV
To reduce the risk of neonatal water aspiration it has been suggested that salt should be added to the water, making it more isotonic.
During a normal delivery, as soon as the chest is no longer compressed, air is sucked into the lungs. If delivery is below water, water from the bath will be inhaled into the lungs. In the surveillance study4 two of the 37 babies born in water were said to have inhalation of water; described as water aspiration for one and freshwater drowning for the other. However, in total 15 had lower respiratory tract problems and eight of these required respiratory support. Birthing pool water is likely to be tap water at a lower osmotic pressure than amniotic fluid. If this water is rapidly absorbed it could, in theory, lead to rapid haemodilution and circulatory overload. Evidence Level IV
Although the risk to the baby of serious infection appears to be low, minimising contamination of the water by strict adherence to procedures for cleaning pools should help minimise any risk of infection.
During normal delivery there is often a discharge of maternal bowel contents as the rectum and perineum are compressed during the second stage. This could lead to an increased risk of neonatal and/or postpartum infection, as well as possibly increasing the risk to staff attending the woman. There has also been concern about possible contamination with pseudomonas leading to clinical infection.5,6 However, in the surveillance study,4 only three babies were reported to have evidence of infection. One of these was a perinatal death following neonatal herpes. Evidence Level IV
Lowering the level of water prior to delivery may avoid cord traction and reduce snapping of the umbilical cord.
An unexpected finding in the surveillance study [4] was that five of the 37 babies (14%) born in water and admitted to special care had a snapped umbilical cord. One baby required transfusion. One suggested mechanism for this is that bringing babies immediately to the water surface may, if the cord is short, result in greater tension on the cord than for a conventional delivery. Evidence Level IV
The newborn baby should be exposed to an adequate cold stimulus to optimise the breathing reflex before oxygen supply from the placenta ceases, which means removing the baby from the water.
In lambs, warmth and immersion in water lead to respiratory depression. A less pronounced respiratory depression occurs when the head is raised out of warm water or when warm water enters the upper respiratory tract. Conversely cold is a strong stimulator of breathing. Evidence Level IV
It is suggested that until further evidence becomes available, it would be prudent to advise women to leave the pool for the third stage.
Warmth has a relaxing effect on uterine muscles that could, theoretically, lead to increased bleeding after delivery of the placenta, or possibly retained placenta. The amount of blood lost during delivery may also be difficult to estimate when diluted in the birthing pool water. Leaving the pool at the end of the second stage might reduce these problems, although there are no trials addressing this question.
If the placenta is delivered in water, the combination of vasodilatation and increased hydrostatic pressure produces the theoretical risk of water embolism. Again, this is a theoretical risk. Evidence Level IV
It is important that women are properly informed about the possibility that they may be advised to leave the birthing pool if unexpected complications of labour and delivery arise, and appropriate procedures should be developed for dealing with emergency situations.
If complications develop it is usually necessary for the woman to leave the birthing pool, as it may be impossible to manage the situation in the water. Emergency interventions may be delayed if it is difficult to get the woman out of the bath. Injuries may occur when trying to get out of the bath as quickly as possible. Evidence Level IV
The use of a birthing pool for labour and/or delivery is an option that is now widely offered within maternity units in the UK, and is also available for home births. Although only a small proportion of women do give birth in water, it is likely that many more use birthing pools during labour.
There are no randomised trials comparing the risks of birth in water with the risks of conventional birth. However, data from the surveillance study provides reassurance that the risks are likely to be comparable.
1.Nikodem VC. Immersion in water during pregnancy, labour and birth. In: The Cochrane Library, Issue 3. Oxford: Update Software, 1999.
2.Odent M. Birth under water. Lancet 1983; 11:1476-7.
3.Rosevear SK, Marlow N, Stirrat GM. Birthing pools and the fetus. Lancet 1993; 342:1048-9.
4.Gilbert RE, Tookey PA. Perinatal mortality and morbidity among babies delivered in water: surveillance study and postal survey. BMJ 1999; 319:483-7.
5.Hawkins S. Water vs conventional births: infection rates compared. Nurs Times 1995; 91:38-40.
6.Parker PC, Boles RG. Pseudomonas otitis media and bacteremia following a water birth. Pediatrics 1997;99:653.
Clinical guidelines are: 'systematically developed statements which assist clinicians and patients in making decisions about appropriate treatment for specific conditions'. Each guideline is systematically developed using a standardised methodology. Exact details of this process can be found in 'Guidance for the development of RCOG green top guidelines' (available on the RCOG website - "www.rcog.org.uk"). These recommendations are not intended to dictate an exclusive course of management or treatment. They must be evaluated with reference to individual patient needs, resources and limitations unique to the institution and variations in local populations. It is hoped that this process of local ownership will help to incorporate these guidelines into routine practice. Attention is drawn to areas of clinical uncertainty where further research may be indicated.
The evidence used in this guideline was graded using the scheme below and the recommendations formulated in a similar fashion with a standardised grading scheme.
Ia Evidence obtained from meta-analysis of randomised controlled trials.
Ib Evidence obtained from at least one randomised controlled trial.
Ila Evidence obtained from at least one well-designed controlled study without randomisation.
Ilb Evidence obtained from at least one other type of well-designed quasi-experimental study.
III Evidence obtained from well-designed non-experimental descriptive studies, such as comparative studies, correlation studies and case studies.
IV Evidence obtained from expert committee reports or opinions and/or clinical experience of respected authorities.
Requires at least one randomised controlled trial as part of a body of literature of overall good quality and consistency addressing the specific recommendation. (Evidence levels Ia, Ib)
Requires the availability of well controlled clinical studies but no randomised clinical trials on the topic of recommendations. (Evidence levels IIa, IIb, III)
Requires evidence obtained from expert committee reports or opinions and/or clinical experiences of respected authorities. Indicates an absence of directly applicable clinical studies of good quality. (Evidence level IV)
Good Practice Point
Recommended best practice based on the clinical experience of the guideline development group.
This Guideline was produced on behalf of the Guidelines and Audit Sub-Committee of the Royal College of Obstetricians and Gynaecologists by:
AH updated 16 July 2000