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South Australian Perinatal Practice Guideline
Fetal Acid Base Balance
Assessment
Department for Health and Wellbeing, Government of South Australia. All rights reserved.
INFORMAL COPY WHEN PRINTED Page 1 of 13
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Note:
This guideline provides advice of a general nature. This statewide guideline has been prepared to promote and facilitate
standardisation and consistency of practice, using a multidisciplinary approach. The guideline is based on a review of
published evidence and expert opinion.
Information in this statewide guideline is current at the time of publication.
SA Health does not accept responsibility for the quality or accuracy of material on websites linked from this site and does not
sponsor, approve or endorse materials on such links.
Health practitioners in the South Australian public health sector are expected to review specific details of each patient and
professionally assess the applicability of the relevant guideline to that clinical situation.
If for good clinical reasons, a decision is made to depart from the guideline, the responsible clinician must document in the
patient s medical record, the decision made, by whom, and detailed reasons for the departure from the guideline.
This statewide guideline does not address all the elements of clinical practice and assumes that the individual clinicians are
responsible for discussing care with consumers in an environment that is culturally appropriate and which enables respectful
confidential discussion. This includes:
The use of interpreter services where necessary,
Advising consumers of their choice and ensuring informed consent is obtained,
Providing care within scope of practice, meeting all legislative requirements and maintaining standards of
professional conduct, and
Documenting all care in accordance with mandatory and local requirements
Explanation of the aboriginal artwork:
The Aboriginal artwork used symbolises the connection to country and the circle shape shows the strong relationships amongst families and the Aboriginal culture. The horse shoe shape
design shown in front of the generic statement symbolises a woman and those enclosing a smaller horse shoe shape depicts a pregnant woman. The smaller horse shoe shape in this
instance represents the unborn child. The artwork shown before the specific statements within the document symbolises a footprint and demonstrates the need to move forward together in
unison.
Purpose and Scope of Perinatal Practice Guideline (PPG)
The purpose of this guideline is to give information about monitoring of fetal wellbeing in
labour. It describes indications and contraindications for fetal scalp blood sampling as well as
how to undertake the procedure. Similarly, information is provided about cord blood gas
sampling as the best determinant of fetal metabolic condition at the moment of birth.
Australian Aboriginal Culture is the oldest living culture in the world yet
Aboriginal people continue to experience the poorest health outcomes when
compared to non-Aboriginal Australians. In South Australia, Aboriginal women are
2-5 times more likely to die in childbirth and their babies are 2-3 times more likely to
be of low birth weight. The accumulative effects of stress, low socio economic
status, exposure to violence, historical trauma, culturally unsafe and discriminatory
health services and health systems are all major contributors to the disparities in
Aboriginal maternal and birthing outcomes. Despite these unacceptable statistics
the birth of an Aboriginal baby is a celebration of life and an important cultural
event bringing family together in celebration, obligation and responsibility. The
diversity between Aboriginal cultures, language and practices differ greatly and so
it is imperative that perinatal services prepare to respectfully manage Aboriginal
protocol and provide a culturally positive health care experience for Aboriginal
people to ensure the best maternal, neonatal and child health outcomes.
South Australian Perinatal Practice Guideline
Fetal Acid Base Balance Assessment
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Flowchart: Fetal Scalp Blood Sampling
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Table of contents
Purpose and Scope of Perinatal Practice Guideline (PPG) ...................................................... 1
Flowchart: Fetal Scalp Blood Sampling ..................................................................................... 2
Summary of Practice Recommendations .................................................................................. 3
Abbreviations ............................................................................................................................. 4
Introduction ................................................................................................................................ 4
Tests to monitor fetal wellbeing in labour .................................................................................. 4
Fetal scalp stimulation ........................................................................................................... 4
Fetal electrocardiograph (ECG) ST analysis ......................................................................... 5
Fetal pulse oximetry ............................................................................................................... 5
Fetal scalp blood sampling ........................................................................................................ 5
Fetal scalp lactate and pH levels ........................................................................................... 6
Indications for fetal scalp blood sampling .............................................................................. 6
Contraindications to fetal scalp blood sampling .................................................................... 6
Management of fetal scalp blood sampling ........................................................................... 6
Procedure for fetal scalp blood sampling .............................................................................. 7
Results ................................................................................................................................... 8
Cord blood gases ....................................................................................................................... 9
Indications .............................................................................................................................. 9
Considerations ....................................................................................................................... 9
Technique for obtaining umbilical cord blood gases ............................................................ 10
References ............................................................................................................................... 11
Acknowledgements .................................................................................................................. 12
Document Ownership & History ............................................................................................... 13
Summary of Practice Recommendations
In tertiary centres, fetal scalp blood sampling (FBS) should be considered part of routine care
for the management team when indicated.
Interpretation of FBS results should take into account any previous scalp pH or lactate results,
labour progress and the complete clinical picture.
FBS should not be undertaken in the presence of maternal infection, fetal bleeding disorders,
malpresentation (e.g. breech, brow, face) or when there is clear evidence of sustained serious
fetal compromise on CTG.
FBS is not recommended in pregnancies less than 35 weeks gestation.
Scalp lactate rather than pH measurement may be easier to perform and more affordable.
Undertaking FBS may unnecessarily increase the decision to birth interval when expediting
birth is indicated (e.g. evidence of serious fetal compromise).
Paired umbilical arterial and venous cord blood gases should be taken whenever fetal
compromise is suspected (see Indications).
Once available, abnormal cord blood gas results should be discussed with the neonatal/
paediatric team.
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Abbreviations
CTG Cardiotocography
FHR Fetal Heart Rate
ECG Electrocardiography
cm Centimetres
RANZCOG Royal Australian and New Zealand College of Obstetricians and
Gynaecologists
HIV Human Immunodeficiency virus
mL Millimetre(s)
e.g. For example
% Percentage
RCOG Royal College of Obstetricians and Gynaecologists
i.e. That is
C Celsius
g Gauge
mmol/L Millimols per litre
pCO2 Partial pressure of Carbon Dioxide
FBS Fetal Blood Sampling
Introduction
Intrapartum fetal surveillance frequently involves the use of a cardiotocograph (CTG).1 The
CTG is an electronic method of simultaneously recording the fetal heart rate (FHR), fetal
movements and uterine contractions to identify the probability of fetal hypoxia. In nearly half
of all CTG tracings, an abnormal fetal heart rate is observed, but only a small proportion of
these fetuses are actually hypoxic.2 Cardiotocography has a high degree of sensitivity but a
low level of specificity.3 Fetal blood sampling is usually performed to better assess fetal acid-
base status in the setting of an abnormal CTG.3
Tests to monitor fetal wellbeing in labour
Several ancillary tests to continuous fetal heart rate monitoring have been proposed to
decrease the false positive rate, or even to replace it completely. These include:
? Fetal scalp blood sampling*
? Fetal scalp stimulation
? Fetal ECG ST analysis
? Fetal oximetry
The gaps in understanding of the precise pathophysiology of the development of
metabolic acidosis during labour hinders the efficacy of ALL of the above fetal tests.4
*Fetal scalp blood sampling will be discussed in detail below
Fetal scalp stimulation
Fetal scalp stimulation during vaginal examination is a non-invasive assessment of the fetus
that may provide assurance alongside continuous fetal heart rate monitoring and fetal scalp
blood sampling in cases of suspected fetal compromise. The likelihood ratio of an
acceleration following fetal scalp stimulation for having low scalp pH is 0.5.7 If fetal scalp
stimulation leads to an acceleration in the fetal heart rate, clinicians can regard this as a
reassuring feature and take this into account whilst reviewing the whole clinical picture.5
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Fetal electrocardiograph (ECG) ST analysis
Meta-analysis of randomised controlled trials has shown fetal ECG ST analysis reduces the
need for fetal scalp blood sampling by about 40%. However, the trends to lower rates of low
Apgar scores and acidosis were not statistically significant.6 ST analysis of the fetal ECG in
labour reduces the need for fetal blood sampling but has no other statistically significant
benefit and does not reduce the caesarean section rate.6
Currently, RANZCOG states there is insufficient evidence to recommend routine fetal ECG
ST analysis for use in intrapartum fetal surveillance.1
Fetal pulse oximetry
Currently, RANZCOG states there is insufficient evidence to recommend routine fetal pulse
oximetry for use in intrapartum fetal surveillance.1
Fetal pulse oximetry results are affected by the presence of meconium and blood and a
recent Cochrane review has concluded that fetal pulse oximetry is not associated with
improvement in fetal outcomes.7
Fetal scalp blood sampling
A recent systematic review of intermittent auscultation versus continuous CTG in both low
and high risk women reveals a significant increase in the caesarean section rate in the CTG
group, whether fetal blood sampling was deployed in labour or not.1,8 It is therefore possible
that the availability of fetal blood sampling in labour will lessen the increase in the caesarean
rate that comes as a consequence of using continuous CTG.8
Although fetal scalp blood sampling is generally considered to be a safe test, rare
complications (e.g. haemorrhage, scalp abscess and drainage of cerebrospinal fluid) and
questions regarding the accuracy of current, normal and abnormal values for fetal scalp pH
(derived from two small studies) as well as the accuracy of pH levels obtained from a fetal
scalp venous sample have led some medical experts to question if this procedure is clinically
and scientifically acceptable.4,8
RANZCOG supports the practice of fetal scalp blood sampling, particularly in larger units that
have ready access to operative delivery if required.1 However, RANZCOG acknowledge that
it is not practical for ALL Australian and New Zealand hospitals to provide fetal blood
sampling. For example, in some hospitals, undertaking fetal blood sampling may delay a
necessary birth and thereby worsen outcomes by lengthening the decision to birth interval for
an emergency caesarean section.1
? In the past, some hospitals interested in providing fetal blood sampling were unable
to because of the costs of maintaining the necessary hardware. More recently, the
introduction and validation of scalp lactate measurement has provided an affordable
alternative.1 If fetal scalp blood sampling is indicated, the use of scalp lactate rather
than pH measurement will provide an easier and more affordable adjunct to electronic
fetal heart rate monitoring for most units.1,9
? If fetal scalp blood sampling is performed, the scalp lactate or pH result should be
interpreted taking into account any previous lactate or pH measurement, the rate of
progress in labour and the clinical features of the woman and baby.1,5
? Inform the senior consultant obstetrician on call if any fetal scalp blood sample result
is abnormal
In situations where fetal blood sampling is contraindicated (see below) or not possible,
decisions regarding birth should take into account the severity of the fetal heart rate
abnormality and the clinical situation. Birth should be expedited where:
? There is clear evidence of serious fetal compromise (fetal scalp blood sampling
should not be undertaken)1
? CTG abnormalities are of a degree requiring further assessment, but fetal scalp blood
sampling is contraindicated, clinically inappropriate or unobtainable1
? The decision to birth interval may be prolonged by virtue of location, clinical staff
availability, patient factors or access to clinical services1
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Fetal scalp lactate and pH levels
A randomised, controlled multicentre trial showed pH analysis and lactate analysis of fetal
blood have comparable results in the management of intrapartum fetal compromise.2 If fetal
blood sampling is indicated, the use of scalp lactate rather than pH measurement is easier to
perform for clinicians, is more affordable and requires a smaller volume of blood.1
Indications for fetal scalp blood sampling
Factors including clinical history, parity, evolution of the fetal heart rate pattern, stage and rate
of progress in labour influence the decision for fetal scalp blood sampling.
Fetal scalp blood estimation may be of value in the following circumstances:
? Bradycardia
? Complicated tachycardia
? Recurrent decelerations
? Prolonged episodes of bradycardia or undefined deceleration patterns
? Prolonged loss of variability which does not spontaneously correct with fetal
stimulation
? Miscellaneous e.g. non-specific concerns about fetal wellbeing
Contraindications to fetal scalp blood sampling
? Clear evidence on CTG of serious, sustained fetal compromise
? Maternal infection e.g. Hepatitis B, C, HIV, herpes simplex virus and suspected
intrauterine sepsis
? Fetal bleeding disorders (e.g. suspected fetal thrombocytopenia, haemophilia)
? Face or brow presentation
? Fetal blood sampling is not generally recommended in pregnancies at less than 34+6
weeks of gestation because birth may be inappropriately delayed in a small at risk
fetus that may sustain damage earlier than would be expected in a term fetus 1
? If a fetus is in a breech presentation during labour and is exhibiting signs of fetal
compromise that are not readily remediable, it would be more appropriate to deliver
the baby by caesarean section than to undertake fetal blood sampling1
Management of fetal scalp blood sampling
In tertiary centres, fetal scalp blood sampling should be considered part of routine care for the
management team when indicated, and a competency the resident medical officer or registrar
should be able to fulfil. Ensure the blood gas analyser has been calibrated according to local
hospital guidelines prior to the processing of samples.
Explain the following to the woman:5
? Why the test is being advised
? The blood sample will be used to measure the level of acid in the baby's blood, to see
how well the baby is coping with labour
? The procedure will require her to have a vaginal examination using a small device
similar to a speculum
? A sample of blood will be taken from the baby's head by making a small scratch on
the baby's scalp. This will heal quickly after birth, but there is a small risk of infection
? The procedure can help to reduce the need for further, more serious interventions
? What the different outcomes of the test may be (normal, borderline and abnormal)
and the actions that will follow each result
? There is a small chance that it will not be possible to obtain a blood sample
(especially if the cervix is less than 4 cm dilated). If a sample cannot be obtained, a
caesarean section or instrumental birth (forceps or ventouse) may be needed
because otherwise it is not possible to find out how well the baby is tolerating labour
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Procedure for fetal scalp blood sampling
Position:
The preferred maternal position is left-lateral position with hips well flexed and the lower leg
extended. The upper leg should be flexed (held by an assistant or positioned in a stirrup) with
the buttocks extending over the edge of the bed to allow the clinician to be positioned below
the level of the maternal vagina. If lithotomy position is used, ensure a lateral wedge is used
to prevent aortocaval compression.
Procedure:
? Disposable fetal scalp blood sampling kits should be available for clinician use
? Attach the fetal scalp blade (depth of 2 mm) to an introducer
? Under direct vision, insert the amnioscope with light source into the posterior fornix
? The clinician obtaining the scalp sample should aim to angle the amnioscope
downward below the horizontal plane
? Once past the anterior lip of the cervix, angle the cone anteriorly into the cervix to
visualise the presenting part
? Clean the fetal scalp surface with chlorhexidine / alcohol-soaked gauze
? Apply sterile liquid paraffin to the fetal scalp (forms a non-wettable surface and
encourages beading of fetal scalp blood)
? Make a quick stab with the fetal scalp blade / introducer to achieve a clean incision on
the fetal scalp
? As the fetal blood appears, insert the heparinised capillary tube to touch the drop of
blood, and keeping the tube angled downward, the blood is allowed to flow by gravity
o FBS for pH: Let the tube fill with at least 2 cm of blood (without air bubbles or
liquor)
o FBS for lactate: A minimum of 5 microlitres of blood is required (without air
bubbles or liquor)
? Immediately pass the sample to an assistant for processing
? Obtain two samples
? Apply pressure with a swab to the fetal scalp over the next two contractions and
observe to ensure the bleeding has stopped
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Results
The following thresholds are suggested and clinicians should be aware that thresholds
may vary between institutions:
Fetal scalp blood sampling
Lactate and pH result Management
Lactate < 4.1 mmol/L
Fetal scalp blood sample is normal
Offer repeat sampling no more than 1 hour later if this is
still indicated by the CTG trace, or sooner if additional
signs of fetal compromise or abnormal features become
evident5
pH ? 7.25
Lactate 4.1- 4.7 mmol / L
Fetal blood sample result is borderline
Offer repeat sampling no more than 30 minutes later if
this is still indicated by the CTG trace, or sooner if
additional signs of fetal compromise or abnormal features
become evident5
Take into account the time needed to take a fetal blood
sample when planning repeat fetal sampling5
Note: Notify obstetrician on call to consider further
management/mode of birth if rapid fall since last sample
pH 7.21 7.24
Second fetal scalp blood
sample result is stable and
no further signs of fetal
compromise
If the CTG trace remains unchanged and the fetal scalp
blood sample result is stable (that is lactate or pH is
unchanged) after a second test, further samples may be
deferred unless additional signs of fetal compromise or
abnormal features are seen 5
Lactate > 4.7 mmol / L
Birth indicated
Rapid deterioration in features of fetal compromise
requires obstetric review of timing and mode of birth
Consider the woman s complete history (e.g. presence of
meconium, progress, fetal scalp lactate or pH value)
when assessing need for caesarean section (category 1)
pH ? 7.20:
Lactate of ? 5.8 mmol / L
Requires an urgent assisted vaginal birth if possible or a
category 1 caesarean section
pH < 7.00
Discuss with the senior obstetrician if:
? A fetal blood sample cannot be obtained, OR
? A third fetal blood sample is thought to be needed
Fetal scalp blood sample cannot be obtained
If a fetal scalp blood sample is indicated and the sample cannot be obtained, but the
associated scalp stimulation results in fetal heart rate accelerations, a decision whether to
continue the labour or expedite the birth will be made in consideration of the clinical
circumstances and in discussion with the consultant obstetrician on call and the woman.5
If a fetal scalp blood sample is indicated but a sample cannot be obtained and there is no
improvement in the CTG trace, advise the woman that the birth should be expedited.3
? Notify the anaesthetist and paediatrician
? Urgency of birth should take into account the severity of fetal compromise and
relevant maternal factors
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No sample or one contaminated with liquor or inadequate volume sample obtained:
Review indication for fetal scalp blood sampling and current CTG trace. Consider the need for
birth in consultation with the senior obstetrician on call.
Cord blood gases
Fetal arterial and venous cord gases (pH, base excess and lactate) are not required for
uncomplicated term spontaneous vaginal births.
Even when paired samples are obtained it cannot always be assumed that one is from an
artery and one from the vein. Fetal carbon dioxide is removed from the umbilical arterial blood
in the placenta, umbilical venous blood should have a slightly higher pH and lower pCO2 than
umbilical arterial blood.12
Umbilical cord blood gas sampling is the most objective determinant of fetal metabolic
condition at the moment of birth.13
Values from the umbilical cord artery provide the most accurate information regarding fetal
and newborn acid-base status.13 Information gained from umbilical cord blood sampling can
be useful from a medical and medicolegal perspective.14
A cord base excess of 12 to 16 mmol/L is associated with encephalopathy in 10 % of
neonates, and the rate increases to 40 % in neonates who have an umbilical arterial base
deficit greater than 16 mmol/L.13
Indications
Where facilities are available, paired umbilical arterial and venous cord blood gas samples
(pH, base excess and lactate) should be taken after birth in the following situations1, 13, 14:
? When the clinicians are concerned about a potential fetal metabolic abnormality
? Preterm gestation
? Meconium stained liquor
? Assisted emergency birth (i.e. ventouse, instrumental, emergency caesarean section)
? Vaginal breech birth
? Shoulder dystocia
? Intrapartum fever (? 38 C)
? Maternal thyroid disease
? Multiple pregnancy
? Small for gestational age baby
? Intrapartum haemorrhage
? Intrapartum fetal scalp pH performed
? Any significant intrapartum CTG abnormality
? Apgar ? 4 at 1 minute
? Apgar ? 7 at 5 minutes
? Planned neonatal nursery admission
Considerations
It is imperative to clamp the cord as soon as possible after the birth because a delay in
clamping may significantly affect pH and gas values due to gaseous diffusion and continuing
metabolism.14 However, clinicians should be aware of maternal requests regarding delayed
cord clamping and the individual clinical scenarios.
Most studies have determined that a cord blood sample is stable for assessment of both pH
and base deficit for 60 minutes when collected in a syringe flushed with heparin and
transported to the cord blood gas analysis machine on ice.14
Arterial pH, base excess and lactate at birth can be estimated from testing a blood sample
obtained from a clamped umbilical cord kept at room temperature for up to 90 minutes after
birth.14
If obtaining umbilical cord artery blood samples is difficult, the vessels on the fetal surface of
the placenta can be used (arteries cross over veins) and will provide similar, but not
necessarily equivalent results.14
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If the baby is born in poor condition (the Apgar score at 1 minute is 5 or less), a 10-20cm
segment of umbilical cord is doubly clamped as soon as possible after birth to allow paired
cord blood gases to be taken.14
It is important to label the samples as either arterial or venous.
Where paired umbilical cord blood gas analysis is taken at birth as part of a clinical audit
regimen, this process should not interfere with management of the third stage of labour.1
Ensure the time that the cord was clamped post birth is recorded in the baby s case notes.
Technique for obtaining umbilical cord blood gases
If acid-base analysis is planned, the cord should be clamped as soon as possible following
the birth of the baby.
Technique One
1. A 10-20cm segment of umbilical cord is doubly clamped as soon as possible after
birth and prior to the delivery of the placenta
2. Collect cord blood gases from the cord vessels above the bottom clamp prior to
collecting routine cord blood samples
Technique Two
1. A 10-20cm section of umbilical cord can be double clamped prior to the delivery of
the placenta. A third clamp can be placed above the isolated section. The isolated
section can be detached and set aside in order to take arterial and venous paired
samples
2. Cord blood gases can then be collected from the detached cord section. After the
birth of the baby, clamp and cut the umbilical cord to separate the baby from the
placenta as in normal vaginal birth. If the Apgar is less than 5 at one minute, clamp
and cut the cord immediately
For all collections
? Use heparinised blood gas syringes (pre-packed if available) or attach a 21 g (green)
needle to each heparinised blood gas syringe
? Identify one artery and vein separately
? Collect the arterial sample first
? Clean the segment of the cord that the sample will be collected from with a clean
perineal pad to remove maternal blood or contaminants
? Insert the needle parallel to the vessel (less likely to go through the back of the artery
into the vein) and withdraw a minimum of 0.2 mL from the artery
? Remove the needle with caution as blood may spray up from the puncture site,
discard into the sharps receptacle, expel air from the syringe and cap with the stopper
provided
? Invert tube to mix specimen and hand the specimen to the assistant to label
appropriately with unique neonatal identification labels, date and time of collection
and whether the source of the sample is arterial or venous
? Then collect the venous blood gas specimen in the same way
Facilitate timely analysis and reporting of cord blood gases per individual hospital policy
Suggested levels for reporting to neonatologists include (if local hospital polices are not in
place):
? pH < 7.15
? Base Excess > -10
? Lactate > 5
? Haemoglobin < 140
? Glucose < 3
Once available, abnormal results should be discussed with the neonatal team and
documented in the baby s case notes, including the agreed plan. Normal results should also
be documented in the case notes.
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References
1. The Royal Australian and New Zealand College of Obstetricians and Gynaecologists.
Intrapartum Fetal Surveillance Clinical Guideline 3rd Ed. 2014.
2. Wiberg-Itzel E, Lipponer C, Norman M, et al. Determination of pH or lactate in fetal
scalp blood in management of intrapartum fetal distress: randomised controlled
multicentre trial. BMJ 2008; 336(7656): 1284.
3. Baker L, Beaves M, Wallace E. Assessing Fetal Wellbeing a Practical Guide.
Melbourne, Victoria: RANZCOG & Monash Health; 2016.
4. Chandraharan E. Fetal scalp blood sampling during labour: is it a useful diagnostic
test or a historical test that no longer has a place in modern clinical obstetrics? BJOG:
An International Journal of Obstetrics & Gynaecology. 2014; 121(9): 1056-62.
5. National Institute for Health and Care Excellence (NICE). Intrapartum care for healthy
women and babies - Clinical Guideline. 2014, Dec 3. UK: NICE; 2014. Available from:
https://www.nice.org.uk/guidance/cg190.
6. Steer PJ, Hvidman LE. Scientific and clinical evidence for the use of fetal ECG ST
segment analysis (STAN). Acta Obstetricia et Gynecologica Scandinavica 2014;
93(6): 533-8.
7. East C, Begg L, Colditz P, Lau R. Fetal pulse oximetry for fetal assessment in labour.
Cochrane Database of Systematic Reviews; 2014. Issue 10. Art. No.: CD004075.
1. DOI: 10.1002/14651858.CD004075.pub4 Available from:
http://www.cochrane.org/CD004075/PREG_fetal-pulse-oximetry-for-fetal-
assessment-in-labour.
8. Alfirevic Z, Devane D, Gyte GML. Continuous cardiotocography (CTG) as a form of
electronic fetal monitoring (EFM) for fetal assessment during labour. Cochrane
Database of Systematic Reviews; 2013. Issue 5. Art. No.: CD006066.DOI:
10.1002/14651858.CD006066.pub2. Available from:
http://dx.doi.org/10.1002/14651858.CD006066.pub2.
9. East C, Leader L, Sheehan P, Henshall N, Colditz P, Lau R. Intrapartum fetal scalp
lactate sampling for fetal assessment in the presence of a non-reassuring fetal heart
rate trace. Cochrane Database of Systematic Reviews; 2015. Issue 5. Art. No.:
CD006174.DOI: 10.1002/14651858.CD006174.pub3. Available from:
http://onlinelibrary.wiley.com/doi/10.1002/14651858.CD006174.pub3/full.
10. Andres RL, Saade G, Gilstrap LC, et al. Association between umbilical blood gas
parameters and neonatal morbidity and death in neonates with pathologic fetal
acidemia. American Journal of Obstetrics and Gynecology. 1999; 181(4): 867-71.
11. Freeman R, Garite T, MP N. Fetal Heart Rate Monitoring. 3rd ed. Philadelphia:
Lippincott Williams & Wilkins; 2003.
12. Armstrong L, Stenson BJ. Use of umbilical cord blood gas analysis in the assessment
of the newborn. Archives of Disease in Childhood - Fetal and Neonatal Edition 2007;
92(6): F430.
13. The American College of Obstetricians and Gynaecologists (ACOG). Umbilical cord
blood gas and acid-base analysis ACOG. Committee Opinion No. 348, November
2006: 108(5): 1319-22.
14. Ramin S. Umbilical cord blood acid-base analysis at delivery. In: Lockwood C, Ed.
2016 Oct 6 [cited 2017 Jan 2]. Available from: https://www.uptodate.com.
South Australian Perinatal Practice Guideline
Fetal Acid Base Balance Assessment
INFORMAL COPY WHEN PRINTED Page 12 of 13
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Acknowledgements
The South Australian Perinatal Practice Guidelines gratefully acknowledge the contribution of
clinicians and other stakeholders who participated throughout the guideline development
process particularly:
Write Group Lead
Dr Angela Brown
Write Group Members
Lyn Bastian
Dr Aishah Yasin
A/Prof Rosalie Grivell
Rachael Yates
Dr Sameer Dikshit
SAPPG Management Group Members
Sonia Angus
Lyn Bastian
Dr Elizabeth Beare
Elizabeth Bennett
Dr Feisal Chenia
John Coomblas
Dr Danielle Crosby
Dr Vanessa Ellison
Jackie Kitschke
Dr Kritesh Kumar
Catherine Leggett
Dr Anupam Parange
Rebecca Smith
A/Prof Chris Wilkinson
South Australian Perinatal Practice Guideline
Fetal Acid Base Balance Assessment
INFORMAL COPY WHEN PRINTED Page 13 of 13
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Document Ownership & History
Developed by: SA Maternal, Neonatal & Gynaecology Community of Practice
Contact: HealthCYWHSPerinatalProtocol@sa.gov.au
Endorsed by: SA Health Safety and Quality Strategic Governance Committee
Next review due: 14/11/2022
ISBN number: 978-1-74243-935-8
PDS reference: CG233
Policy history: Is this a new policy (V1)? N
Does this policy amend or update and existing policy? Y
If so, which version? V5
Does this policy replace another policy with a different title? N
If so, which policy (title)?
Approval
Date
Version
Who approved New/Revised
Version
Reason for Change
25/11/20 V5.1
Interim Chair, SA Maternal, Neonatal &
Gynaecology Community of Practice
Re-templated, risk assessed and
extended for 2 years
14/11/17 V5
SA Health Safety and Quality Strategic
Governance Committee
Reviewed and merged with Umbilical
Cord Blood Gas Sampling PPG
19/04/16 V4
SA Health Safety and Quality Strategic
Governance Committee
Reviewed
22/11/11 V3
SA Health Maternal and Neonatal
Network
Reviewed
23/10/07 V2
SA Health Maternal and Neonatal
Network
Reviewed
18/03/04 V1
SA Health Maternal and Neonatal
Network
Original SA Health Maternal and
Neonatal Network approved version.
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