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Rapid Responses: Rapid Responses published:
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Water Birth
- Robert Fox (1 September 1999)
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Water Birth: What''s Next
- Michel R Odent (8 September 1999)
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Response to: Perinatal mortality and morbidity among babies delivered in water.
- Meena Anand (10 September 1999)
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Authors'' reply
- Ruth Gilbert, Pat Tookey (13 October 1999)
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Severe blood loss in a neonate due to a ruptured umbilical cord in a bath delivery
- Jan H de Graaf (25 February 2000)
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Re: Water Birth
- M L Lim (30 March 2001)
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Robert Fox
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EDITOR - I was pleased to find the article Ruth Gilbert and Pat Tookey reporting their survey of water birth.1 Theirs is an important assessment of a medical device which was introduced widely into clinical practice with little prior assessment of safety. I am concerned that the results of this study might be susceptible to misinterpretation, however. There is a distinction to be made between water birth and labour in water. Many women present to the delivery suite in late labour and the majority will deliver within less than four hours. The time spent in the pool is often very short therefore. In contrast, women admitted in early labour may spend many hours in water, particularly those who use the birthing pool for analgesia during the first stage. In order to optimise the analgesic properties, the water is often maintained at a level much higher than room temperature. The effect of prolonged exposure to this environment on maternal and fetal physiology is not precisely known. It is possible that maternal core temperature may rise because shedding of heat is more difficult. Such a effect would tend to increase the fetal metabolic rate and oxygen requirement. At the same time, diversion of maternal blood flow to skin in order to aid heat loss might reduce blood flow (and oxygen delivery) to the placenta. In Bristol, we identified two women who had adverse perinatal outcomes having laboured for more than seven hours in the birthing pool; 1 stillborn child with evidence of asphyxia and 1 baby with severe hypoxic-ischaemic encephalopathy.2 Neither woman delivered in water, both having left the pool a few minutes before. In neither case was any specific cause evident. The denominator of women who had laboured this way was not precisely known but was almost certainly less than 100 suggesting a severe asphyxia rate in excess of 1%. These two cases did not allow us to draw conclusions about the safety of prolonged labour in the birthing pool. Equally, although the paper by Gilbert and Tookey suggests strongly that delivery into water per se is safe, I believe that it does not address the issue of prolonged labour in water and that further research is needed. Such a study most take into account those women who leave the pool as a proportion will do so because complications of labour will have arisen. Robert Fox consultant obstetrician 1. Gilbert RE, Tookey PA. Perinatal mortality and morbidity among babies delivered in water: surveillance study and postal survey. BMJ 1999;319:483 (21 August). 2. Rosevear SK, Fox R, Marlow N, Stirrat GM. Birthing pools and the fetus. Lancet 1993; 342:1048-9. |
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Michel R Odent, Director Primal Health Research Centre. London NW3
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Robert Fox points out that after the publication of the valuable survey by R Gilbert and P Tookey(1) the time has come for further research in order to make the most effective use of the birthing pools. Fox, in his electronic response, addresses the issue of prolonged labour in water and stresses the need to take into account those women who leave the pool because complications have arisen. A Swedish prospective controlled study(2) provides useful answers to his questions. 200 women were randomised to either the "early bath group" or the "late bath group". Women who entered the pool at 5 cm or more had a short labour and a reduced need for oxytocin administration and epidural analgesia. Furthermore the authors reported that no women had to leave the tub because of alterations of the fetal heartbeat. This type of study represents one of the several perspectives suggesting that immersion in water at the temperature of the body tends to facilitate the birth process during a limited length of time (in the region of an hour or two). Data provided by physiologists can help interpreting clinical observation. They indicate that the common response to immersion is a redistribution of blood volume. The increased intra thoracic blood volume stimulates the release of the atrial natriuretic peptide (ANP). The inhibitory effect of ANP on the activity of the posterior pituitary gland has been widely studied regarding the release of vasopressin (which has oxytocic properties). There has been comparatively little study of the effect on oxytocin(3). The effect of central blood volume expansion on the activity of the posterior pituitary gland is slow, in the region of 1-2 hours(4). Without waiting for the results of further research it seems necessary to revise many of the current guidelines regarding the use of water during labour. Helping women to be patient enough to enter the pool around 5 cm appears as a new aspect of the art of midwifery. A birth under water should not be programmed: when the parturient is "the prisoner of a project", she may be tempted to stay in the bath while the contractions are getting weaker, with the risk of long second and third stages. Updated protocols should accept that "in any hospital where a pool is in daily use a birth under water is bound to happen now and then"(5). References: 1-Gilbert RE, Tookey PA. Perinatal mortality and morbidity among babies delivered in water: surveillance study and postal survey. BMJ 1999; 319:483-7. 2-Eriksson M, Mattsson LA, Ladfors L. Early or late bath during the first stage of labour: a randomised study of 200 women. Midwifery 1997; 13(3):146-8. 3-Gutkowska J, Antunes-Rodrigues J, McCann SM. Atrial Natriuretic Peptide in brain and pituitary gland. Physiol Rev 1997; 77: 465-515. 4-Norsk P, Epstein M. Effects of water immersion on arginine vasopressin release in humans. J Appl Physiol 1988; 64(1):1-10. 5-Odent M. Birth underwater. Lancet 1983; ii:1476-7 Competing interests: none |
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Meena Anand, 4th year medical student University of Newcastle upon Tyne
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Dear Editor, Gilbert and Tookey reviewed perinatal mortality and morbidity in water births in NHS centres nationally.(1) The authors were successful in collecting information on a large proportion of water deliveries by surveying all 1500 consultant paediatricians in the British Isles, and all NHS Maternity Units. The small amount of under reporting that occurred was unavoidable and acknowledged by the authors. However, we wish to raise three issues concerning this study. Firstly an assumption was made regarding the apparent low risk of all deliveries taking place as water births. The water birth study group undoubtedly contained some high risk deliveries, for example a delivery that was both concealed and unattended. The control studies selected by the authors were specifically chosen for their use of low risk status deliveries. This means however that the study population of water births and the control populations are not directly comparable. We feel that by adopting some inclusion criteria that define exactly what is meant by low risk deliveries the authors would be better able to compare the two populations. A further concern is that whilst only 9% of the total number of water births occurred at home, 35% of the total complications occurred in these births. Can home water births therefore be included in the same group as hospital water births? Perhaps separating these subgroups would provide a clearer indication of the risks involved at home and in hospital for women choosing a water birth delivery. Finally in this study 83% of deliveries in water took place in Southern England. This geographical skew may be a result of the socio-economic influences upon the decision to have a water birth. However clearer inferences could have been made about class and the impact on the choice of delivery if information about the socio-economic class of the women were collected. Meena Anand, Tom Bennett Britton BA (Hons), Charlotte Lees, Jo Parry-James B.Med.Sci (Hons), Rachel Wilkinson. meena.anand@ncl.ac.uk 4th Year Medical Students, Department of Epidemiology and Public Health, School of Health Sciences, Medical School, University of Newcastle Upon Tyne NE2 4HH, UK. Word count = 343 1 Gilbert RE, Tookey PA. Perinatal mortality and morbidity among babies delivered in water: surveillance study and postal survey. BMJ. 1999; 319:483-487. |
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Ruth Gilbert, Senior Lecturer in Clinical Epidemiology, Senior Research Fellow Institute of Child Health, UCL, London, Pat Tookey
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Response to Dr Fox We sought information on deaths and admission for special care following both delivery in water and labour only in water. Women who delivered in water spent longer in water (median 185, range 45-610 minutes) than women who laboured in water and delivered conventionally (median 150, range 15- 610 minutes). These results should be treated with caution as temperature was not recorded in 26/64 (41%) deliveries and we agree with Dr Fox that monitoring of both temperature and time immersed is important. Our data show that babies born to women delivering in water had a similar rate of hypoxic ischaemic encephalopathy (grade 2 and 3) compared with term babies (1.2/1000 and 2 /1000 live births respectively1. Although there may have been under-reporting of babies admitted for special care with hypoxic ischaemic encephalopathy, these results provide no evidence to support the suggestion that immersion in water increases the risk of hypoxic ischaemic encephalopathy. Further research to determine the risks of hypoxic ischaemic encephalopathy associated with prolonged immersion would require a very large sample size given the rarity of this condition in low risk deliveries. Reference 1. Levene ML, Kornberg J, Williams THC. The incidence and severity of post-ashyxial encephalopathy in full term infants. Early Hum Dev 1985;11:21-6. Response to Anand et al. As Anand et al point out, we included all deliveries in water even though some could be classified as 'high risk'. This is likely to overestimate the risks associated with delivery in water and therefore strengthens our conclusions that the perinatal mortality rate was similar to the rate for 'low risk' conventional deliveries. The request for subgroup analyses is unrealistic given the limited numbers involved. |
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Jan H de Graaf
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In the Netherlands, bath delivery is increasingly gaining support because of the supposedly advantages such as reduced maternal pain and stress. About the risks involved, especially for the neonate, little is known, but a recent study in the British Medical Journal shed some light on this issue.[1] We recently encountered a serious complication of a bath delivery. A healthy 26-year-old mother, first time pregnant, had an uncomplicated pregnancy. At 39 weeks gestation she gave birth with delivery in a bath at home, attended by her midwife. A son of 3 kilograms was born, and immediately after birth, he was taken out of the water and put on the mothers chest. The umbilical cord was hanging in the bath water, which was turbid due to blood loss during delivery. After 3 minutes the child became increasingly pale and was having trouble breathing. He was taken out of the bath and a total ruptured umbilical cord was noted with substantial blood loss from the child. The cord was then clamped and the child had to be resuscitated. He was then admitted to our neonatology intensive care unit. On physical exam 1 hour after birth an intensely pale and slightly hypotonic boy with a moaning respiration was observed, pulse 150 beats/minute, and a mean blood pressure of 45 mm Mercury. Laboratory investigations showed a haemoglobin of 7.2 mmol/l with a haematocrit of 35.7%. Blood gas analysis showed a pH of 7.18 with a pCO2 of 5.9 kPa. A chest X-ray performed because of the moaning respiration, showed no abnormalities. He received red blood cell transfusion, after which his clinical condition gradually improved. Haemoglobin after blood transfusion was 9.9 mmol/l. A cranial ultrasound performed the next day showed no abnormalities. He was transferred to a neonatology unit of a nearby hospital for additional care. In this case a ruptured umbilical cord was not noted because of the turbid water. Substantial blood loss occurred, and resuscitation and admission to a hospital was necessary. Rupture of the umbilical cord usually is a rare but potentially dangerous event during birth and may result in severe asphyxia and even death. A ruptured umbilical cord usually is due to a filamentous insertion of the cord and is easily recognised, due to the large amount of blood loss. It is tempting to assume that the ruptured umbilical cord in this case would have been noted earlier if the delivery had not taken place in a bath. In a recent study in this Journal the incidence of ruptured umbilical cords in bath delivery's was found to be as high as 18%. Clearly, impaired visual control by midwifes, general practitioners or obstetricians when guiding a bath delivery is a disadvantage in light of the high incidence of ruptured cords, when compared to other delivery conditions. We feel that lowering the water level is not sufficient for preventing this complication, as was suggested in the previous study. It merely decreases the advantages of giving birth in a bath. We would therefore like to stress the importance of immediate and thorough investigation of the newborn and the umbilical cord after bath delivery . 1. Gilbert RE, Tookey PA. Perinatal mortality and morbidity among babies delivered in water: surveillance study and postal survey. BMJ 1999;319:483-7 Jan H. de Graaf, MD, PhD, Martijn P. Heringa,* MD, PhD, Mar J. Zweens, MD. Department of Pediatrics, Division of Neonatology and the Department of Obstetrics and Gynaecology,* University Hospital Groningen, Hanzeplein 1 9713 GZ Groningen, The Netherlands. Editorial note
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M L Lim, community midwife sister east london
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dear editor In response to these findings of the epidemiologists (Ms Gilbert & Tookey), it is also wise to note the following. A waterbirth is usually a very well selected group. Guidelines for waterbirth of my unit as i am sure like quite a number of other units have always only stipulate inclusion of uncomplicated pregnancies. As it is the authors were rightly so in cautioning the generalization of findings. Given the evidence, i am inclined to feel more reassured in providing waterbirth as a choice not that i ever had to refuse anyone ... Re perinatal morbidity/mortality it would be useful to have a much bigger collaborative study. ml lim RN, RM (DipHE, MSc) |
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