Perinatal mortality and morbidity among babies delivered in water: surveillance study and postal survey
BMJ 1999; 319 doi: https://doi.org/10.1136/bmj.319.7208.483 (Published 21 August 1999) Cite this as: BMJ 1999;319:483
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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
The mother of the baby in this case report has given her signed, informed consent to publication.
Competing interests: No competing interests
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.
Competing interests: No competing interests
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.
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.
Competing interests: No competing interests
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
Competing interests: No competing interests
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
Taunton & Somerset Hospital
TAUNTON TA5 1DA
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.
Competing interests: No competing interests
Re: Water Birth
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)
Competing interests: No competing interests