Research into water immersion/birth is not easy. Often researchers do not clearly distinguish between shallow- or deep-water immersion, and/or confuse labour in water with birth in water. The much-revered randomised controlled trial is not well suited to this subject (Jowitt, 2001), as women prefer to choose options in labour if and when they are ready for them. Being pressured into or denied water immersion/birth following the opening of a brown envelope (even though a woman may have consented to this in principle) may raise anxiety levels and affect labour progress. Research results should, therefore, be interpreted with caution. NICE (2007), for example, feels that the evidence supports water immersion in labour, but does not prove or disprove the benefits of actual birth in water.

Research/anecdotal accounts tend to suggest that:

• Beneficial labour hormone levels in warm water immersion include endorphins and oxytocin, with reduced catecholamine secretion (Odent, 1983; Ockenden, 2001a), which appear to lower pain perception (Ockenden, 2001b).
  
• Less analgesia is needed by women using a pool compared to dry land labour (Garland & Jones, 2000; Otigbach et al., 2000; Burns, 2001; Cluett et al., 2004a). Water in labour appears to be a cost-effective analgesic and is recommended by NICE (2007).
  
• Relaxation. Water offers a peaceful, secure environment, which helps the woman to relax. The woman’s buoyancy in the water encourages her to find comfortable positions enabling her to move freely (Ockenden, 2001b).
  
• Backache appears to be eased (Nightingale, 1996).
  
• Fewer tears. Women birthing in water may experience intact perineums or less severe tears compared to similar births on dry land (Garland & Jones, 2000; Burns, 2001; Garland, 2006), but more research is needed (RCM, 2005)
  
• Postpartum haemorrhage rates appear lower in women having water births, although again further research is needed (Garland, 2006). This is interesting because most third stages following water birth tend to be physiological.
  
• Slow progress may be improved by water immersion (Cluett et al., 2004b).
  
• No difference in length of labour and 5 min Apgar score following use of a waterbirth pool (Garland & Jones, 2000; Burns, 2001).
  
• No apparent increase in neonatal infection or neonatal intensive care unit admission (Cluett et al., 2004a) although further research is needed (Royal College of Obstetricians and Gynaecologists (RCOG)/RCM, 2006).

• Premature gasping: There are anecdotal accounts of babies developing post-birth respiratory distress secondary to water inhalation (Nugyen et al., 2002), but these are not backed up by larger studies. Babies do not appear to gasp or inhale water when born in warm water unless severely hypoxic. Due to fears of premature gasping in cold water, researchers originally suggested that the water should be around body temperature (Johnson, 1996). This has been challenged by Harper (2002) who describes healthy babies born in cold sea as low as 24°C.
  
• Hyperthermia. Fetal temperature is 0.5°C higher than normal (37°C) maternal temperature. If the mother becomes pyrexial, however, there will be a greater relative difference in the mother’s and baby’s temperatures, i.e. the baby will get considerably hotter and will take longer to cool down (Charles, 1998). If the mother becomes significantly overheated in the pool, the baby can become excessively hot and can become severely asphyxiated (Rosevear et al., 1993).
  
• Water embolism. Early concerns about water embolism are hypothetical: there have been no recorded cases.
  
• Infection. There are theoretical concerns about infection but few recorded cases which could not have been due to chance alone. In 1993 one baby born in a home spa bath died from Legionella pneumonia which was isolated from the bath (Nagai et al., 1993). Unlike most birthing pools, spa baths have recesses difficult to access, and it is inadvisable to use these for water births. Confidential Enquiry into Maternal and Child Health (CEMACH) (2004) states that water birth may carry a risk for the mother due to faecal contamination of the perineum and genital tract, but the evidence base is thin.

Mobile pools normally have a single-use disposable liner. (See later in chapter for pool cleaning recommendations.)

• Snapped cord. It has been documented following water birth (Crow & Preston, 2002) and is easily dealt with (see later in chapter).
  
• Slow progress. Women who get in at <5 cm cervical dilation or who stay in >2 hours may find labour slows down (Eriksson et al., 1997; Odent, 1998). This may be due to the absence of the gravity effect, which is known to aid labour progress. The risk may have been overstated since it is easily reversible: i.e. get out of the pool and mobilise. A woman who is very distressed and feeling out of control in early labour may find a period of water immersion an ideal way of relaxing and regaining some control. She also may not want a vaginal examination (VE) prior to entering the pool. Prescriptive restrictions on when a woman should enter the water and how long she should stay in are therefore unhelpful (Garland, 2006). It is just a question of being vigilant to the frequency and strength of contractions, and responding appropriately.

Interestingly, water immersion may actually help some women with slow progress, possibly due to its relaxing effect, reversing the stress response which inhibits contractions (Cluett et al., 2004b).

• Midwifery back pain. This is sometimes an excuse cited by midwives who do not feel comfortable with water birth. In fact, there is rarely any need to lean over the side of the pool, except for fetal heart (FH) auscultation or perhaps briefly to perform a VE. Bend from the hips if you need to lean over. One of the joys of water is that it stops clinicians interfering with the birth process. Like so many labour situations, try to ‘sit on your hands’ and avoid continually leaning over to peer at the perineum. As discussed later, the birth itself should be ‘hands off’. Think about a low stool for sitting alongside the pool.

Each unit will have its own criteria for labouring in water but care should be individualised to meet women’s requests. Ultimately, the woman makes the decision when she has been presented with all the information.

Criteria include the following:

• Women’s informed choice.
  
• Normal, term pregnancy from 37 weeks (RCM, 2000).
  
• Singleton, cephalic presentation (RCM, 2000).
  
• Opioid (e.g. pethidine) given <2 hours ago and the woman is not drowsy (NICE, 2007).
  
• Spontaneous rupture of the membranes of less than 24 hours (RCM, 2000).
  
• Arguably, most situations where intermittent monitoring is being performed. If the woman is not having electronic fetal monitoring (EFM), even if clinicians do not agree with her decision, there are few arguments against water immersion in labour.

• Infection. This is a contentious area, since many trusts may be unhappy to ‘permit’ water birth for women with infections, e.g. HIV, hepatitis B and group B strep. There is no definitive answer to this, but it should always be remembered that many women have infections we know nothing about, so universal precautions should always be practised. Whilst body fluids obviously cannot be so well contained when birth occurs in water, one might speculate that concentrated blood splash injuries might be fewer, since (a) blood is diluted in large volumes of water; (b) the birth is usually ‘hands off’: a sudden gush of fluid will be dispersed in the water, rather than splashing the midwife’s face; and (c) the baby may be partially cleansed of maternal body fluids as it delivers through the water.
  
• Pyrexia. Any woman with a pyrexia should always be recommended to leave the pool due to risk of infection and fetal hyperthermia (Charles, 1998). She will probably be feeling hot and uncomfortable anyway.
  
• Prolonged rupture of membranes. It risks ascending infection – such women are usually advised not to labour in water. Although since it is safe to have a bath with prolonged rupture of membranes (NICE, 2007) one might question the logic of this.
  
• High body mass index. Larger women may benefit from the buoyancy effects, allowing them to take up otherwise awkward positions, e.g. kneeling, but there is a fear that very large women may be difficult to ‘extract’ from the pool in an emergency. This is a delicate subject and should be approached sensitively.
  
• Need for electronic fetal monitoring. It is technically possible to monitor continuously during water immersion (Zanetti-Dallenbach et al., 2007) and waterproof cardiotocography (CTG) leads are available (Price, 2001), but many midwives would be horrified at the idea of a water pool being invaded in this way. If a woman has chosen water birth against advice and EFM would have been recommended, ask her if she would consider as a compromise getting out for an occasional CTG trace. She has every right to refuse.
  
• Heavy bleeding/thick meconium liquor. CTG and closer monitoring would be strongly recommended. Both may result in fetal distress which could cause a baby to gasp prematurely, so water is not advisable. Thin meconium is less of a concern and may not need continuous CTG (NICE, 2007); there is no consensus on this issue.
  
• Oxytocin augmentation. Despite reports of women with an oxytocin infusion labouring successfully in pools (H. Ponette, website; Zanetti-Dallenbach et al., 2007), this is unusual practice in the UK.
  
• Previous caesarean section. If a woman has chosen to have intermittent auscultation for her vaginal birth after caesarean (VBAC) section labour, there is no reason to exclude her from water immersion. A number of units now provide water immersion/birth for VBAC women (Garland, 2006). It is possible that since women will not be using epidural anaesthesia in water, they may be more likely to be aware of the pain of uterine dehiscence.
  
• Multiple birth/breech. There are anecdotal accounts of breech and water births. e.g. German midwife Cornelia Enning and Belgian obstetrician Herman Ponette (see Useful contacts); however, such accounts must be read critically. Ponette also protects the perineum, controls the head and even occasionally clamps and cuts the cord underwater (a highly questionable practice).

Pools are available in many shapes and sizes, fixed or portable. Fill deeply so the woman’s abdomen is covered and she is comfortably buoyant.

Water temperature

There is no clear evidence on optimal pool temperature and local guidelines vary. Burns and Kitzinger (2001) suggest 35–37°C for the first stage and 37°C for the second stage and birth. NICE (2007) recommends ≤37.5°C.

Anderson (2004), however, suggests the mammalian capacity for thermostasis ensures that women will be uncomfortable if they are too hot or cold and agrees with Harper (2002) who says: ‘There is no reason for midwives… to worry over keeping the water at a set temperature other than the mother’s physical comfort’, but ensure the mother does not become pyrexial (Charles, 1998). The RCOG and RCM support this approach (RCOG/RCM, 2006).

The surface temperature is cooler than deeper down, so stir the water well to mix it before measuring the temperature. Hot water may need to be added regularly.

Cleansing

Local infection control policies should cover waterbirth (RCM, 2000). Following use, the pool should be rinsed of debris and cleaned with a chlorine-releasing agent which is effective against HIV, hepatitis B and hepatitis C (Burns & Kitzinger, 2001). Running hospital pool taps for 5 minutes everyday may minimise infection risk (Woodward & Kelly, 2004). Consider also running the taps for a while prior to filling the pool, particularly in any setting where the pool is not frequently used.

Equipment

• Thermometer to check water temperature.
  
• Waterproof fetal heart doppler device.
  
• Lift or aid to get the woman out of the pool in an emergency (if available).
  
• Gauntlet gloves and eye protectors (not all midwives use these).
  
• A small mirror for visualisation of progress during the second stage of labour.
  
• Low stool or step to help the woman in and out easily. The midwife may sit on this too.
  
• Plenty of towels, warmed if possible.
  
• Portable entonox or extended tubing to reach the pool.
  
• Sieve and bowl to collect any faeces.

Water birth at home

Some NHS trusts rent out pools, and many companies offer pool hire (see end of chapter).

Alternatively a home-made tub can be constructed, including:

• Pool liner (available from water birth companies).
  
• Submersible pond pump for emptying the pool (available from garden centres). Alternatively jugs or bowls can be used, but these are extremely time-consuming: both staff and birth partners will have better things to do after the birth than spending an hour emptying the tub.
  
• Plastic sheeting matting (available from garden centres) to cover carpets.

A trial run is advisable. Filling a large pool can take some time and quickly drain a domestic hot water tank. Think about how to maintain a good supply, e.g. ensure when labour starts, the thermostat is set to heat the water at any time of day, and/or consider switching on the immersion heater to the hot water cylinder. Used water should preferably drain down a toilet.

Beware of the danger of water and electricity. Trailing leads and lamps are dangerous. Always have a charged torch to hand.

A structural survey of the floor is rarely indicated, but think about where the pool is to be placed. Be aware that when filled it can weigh up to 850 kg so may be best on the ground floor. Birth pool companies are usually very helpful and have a wealth of experience and literature about home water birth.

(See also Chapter 1.)

First stage of labour

• Check the woman’s temperature hourly (D. Garland, personal communication, 2002).
  
• Allow her to drink freely to avoid dehydration as water immersion has a diuretic effect (Ockenden, 2001b) and the exposed areas of the body will sweat. Encourage birth partners to drink and do the same yourself: humid pool rooms can be enervating for everyone.
  
• Measure and record the water temperature. The frequency may vary with local guidelines, but typically every 30–60 minutes.
  
• VEs are usually performed with relative ease in the pool.

Second stage of labour