abdominal decompression for suspected fetal compromise pre-eclampsia

8/11/2019 Abdominal Decompression for Suspected Fetal Compromise Pre-eclampsia

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Abdominal decompression for suspected fetal compromise/

pre-eclampsia (Review)

Hofmeyr GJ

This is a reprint of a Cochrane review, prepared and maintained by The Cochrane Collaboration and published inThe Cochrane Library

2007, Issue 4

http://www.thecochranelibrary.com

1Abdominal decompression for suspected fetal compromise/pre-eclampsia (Review)

Copyright 2007 The Cochrane Collaboration. Published by John Wiley & Sons, Ltd
http://www.thecochranelibrary.com/http://www.thecochranelibrary.com/


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T A B L E O F C O N T E N T S

1ABSTRACT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

1PLAIN LANGUAGE SUMMARY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

2BACKGROUND . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

2OBJECTIVES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

2CRITERIA FOR CONSIDERING STUDIES FOR THIS REVIEW . . . . . . . . . . . . . . . . . . 2SEARCH METHODS FOR IDENTIFICATION OF STUDIES . . . . . . . . . . . . . . . . . . .

2METHODS OF THE REVIEW . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

2DESCRIPTION OF STUDIES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

2METHODOLOGICAL QUALITY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

3RESULTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

3DISCUSSION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

3AUTHORS CONCLUSIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

3POTENTIAL CONFLICT OF INTEREST . . . . . . . . . . . . . . . . . . . . . . . . . . .

3ACKNOWLEDGEMENTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

3SOURCES OF SUPPORT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

4REFERENCES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

4TABLES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

4Characteristics of included studies . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

5ANALYSES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5Comparison 01. Abdominal decompression for suspected fetal compromise/pre-eclampsia . . . . . . . . . .

5INDEX TERMS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

5COVER SHEET . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

7GRAPHS AND OTHER TABLES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

7Analysis 01.01. Comparison 01 Abdominal decompression for suspected fetal compromise/pre-eclampsia, Outcome 01

Unchanged or worsening pre-eclampsia . . . . . . . . . . . . . . . . . . . . . . . . . .


Induction of labour (all indications) . . . . . . . . . . . . . . . . . . . . . . . . . . .


Induction for placental insufficiency . . . . . . . . . . . . . . . . . . . . . . . . . . .


Fetal distress in labour . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

9Analysis 01.05. Comparison 01 Abdominal decompression for suspected fetal compromise/pre-eclampsia, Outcome 05Low birthweight . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .


Apgar score


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B A C K G R O U N D

Abdominal decompression was developed initially as a method

of enhancing the forward movement of the uterus during labour

contractions with a view to relieving pain. Unanticipated appar-

ent beneficial effects on fetal condition led to its investigation forthis purpose. A rigid dome is placed about the abdomen and cov-

ered with an airtight suit. The space around the abdomen is de-

compressed to -50 to -100mmHg for 15-30 seconds out of each

minute for 30 minutes once to thrice daily, or continuously during

labour. This is thought to pump blood through the intervillous

space. See also (Hofmeyr 1989).

O B J E C T I V E S

To assess the effects on fetal growth and perinatal morbidity and

mortality of abdominal decompression for the treatment of fetal

compromise.

C R I T E R I A F O R C O N S I D E R I N G

S T U D I E S F O R T H I S R E V I E W

Types of studies

Clinical trials comparing the effect of therapeutic abdominal de-

compression on clinically meaningful outcomes, with a control

group (no decompression); random or quasi-random allocation to

the treatment and control group; violations of allocated manage-

ment not sufficient to materially affect outcomes.

Types of participants

Women with pre-eclampsia and/or fetuses that were thought to

be compromised.

Types of intervention

Antenatal abdominal decompression.

Types of outcome measures

Maternal blood pressure and proteinuria, morbidity and perinatal

outcome.

Outcomes included if clinically meaningful; reasonable measurestaken to minimise observer bias; missing data insufficient to ma-

terially influence conclusions; data available for analysis accord-

ing to original allocation, irrespective of protocol violations; data

available in format suitable for analysis.

S E A R C H M E T H O D S F O R

I D E N T I F I C A T I O N O F S T U D I E S

See: methods used in reviews.

This review has drawn on the search strategy developed for the

Pregnancy and Childbirth Group as a whole.Relevant trials were identified in the Groups Specialised Register

of Controlled Trials. See Review Groups details for more

information.

The Cochrane Controlled Trials Register is searched periodically

on the term abdominal decompression. Date of last search: 25

October 2004.

M E T H O D S O F T H E R E V I E W

Trials under consideration were evaluated for methodological

quality and appropriateness for inclusion according to the

prestated selection criteria, without consideration of their results.Individual outcome data were included in the analysis if they met

the prestated criteria in Types of outcome measures. Included

trial data were processed as described in Clarke 1999.

Data were extracted from the sources and entered onto the

Review Manager (RevMan) computer software (Update Software,

Oxford, UK), checked for accuracy, and analysed as above using

the RevMan software. For dichotomous data, relative risks and

95% confidence intervals were calculated, and in the absence of

heterogeneiety, results were pooled using a fixed effects model.

Continuous data were pooled using weighted mean differences

and 95% confidence intervals.

D E S C R I P T I O N O F S T U D I E S

See Table of Characteristics of included studies.

M E T H O D O L O G I C A L Q U A L I T Y

See Table of Characteristics of included studies, particularly the

Methods and Notes sections.

Onestudy (Blecher 1967) does not exclude the possibility of selec-

tion andobserver bias. Allocation of 160 women with pre-eclamp-

sia, essential hypertension or chronic nephritis to study and con-

trol groups was by alternation. Observers were not blind to theallocation of each woman, and the assessment of outcome as un-

changed or worsening pre-eclampsia is somewhat subjective.

MacRae 1971 do notdefine their methodof selectingat random

28womenwithfetusesestimatedtobesmallforgestationalageand




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with urinary oestriol levels below the normal range, for abdominal

decompression, and 28 to serve as controls.

Varma 1973 allocated 140 women with clinically small for dates

fetuses and biparietal diameters below the 10th percentile by al-

ternation to decompression and control groups. The allocation

of seven women from each group was changed because of non-acceptance of abdominal decompression. It has not been possible

to reanalyse the data according to the original constitution of the

groups. The observers were not blind to the allocation of each

woman, and certain of the measures of outcome were to some

extent subjective.

Interpretation of the results of these studies must be guarded be-

cause of the possibility of selection, observer and analysis bias out-

lined above.

R E S U L T S

In the trial reported by Blecher 1967, abdominal decompression

appeared to have a beneficial effect on the progression of pre-

eclampsia. Inboth of the other trials (MacRae 1971; Varma 1973),

abdominal decompression appeared to be associated with a sig-

nificantly greater increase in levels of urinary oestriol, although

only Varma 1973 actually presented data (1.68 [1.21] versus 0.91

[0.74] mg per week, mean values [SD]). In addition, Varma 1973

found that abdominal decompression was associated with statisti-

cally significant faster weekly growth in the fetal biparietal diam-

eter (2.08 [0.36] versus 1.49 [0.71] mm per week, mean values

[SD]). Blecher 1967 did not report a reduction in the incidence

of induction of labour, while Varma 1973 showed a trend to fewerinductions of labour in the decompression group, the more so

for inductions for placental insufficiency. Varma 1973 also re-

ported significantly less fetal distress during labour and depressed

1-minute Apgar scores in the group who had received abdominal

decompression.

Observer bias and possibly reporting bias may account for some

or all of the putative effects of abdominal decompression noted

above. The assessment of birthweight is less susceptible to ob-

server bias, and data are available from all three trials. Abdominal

decompression was associated with a substantial reduction in the

incidence of low birthweight in two of the trials and an increase

in mean birthweight and placental weight in the third (MacRae

1971). Perinatal mortality was also reduced in all three trials.

D I S C U S S I O N

For outcomes assessed in more than one study, all results are com-patible.

A U T H O R S C O N C L U S I O N S

Implications for practice

Because of the methodological shortcomings mentioned above,

clinical use of abdominal decompression cannot be supported on

the basis of these trials.

Implications for research

The large improvement in birthweight and perinatal mortality re-

ported in allthree studies is sufficiently striking to warrant the fur-

ther evaluation of abdominal decompression in cases of impaired

fetal growth, and possibly pre-eclampsia, by means of method-

ologically sound controlled trials.

P O T E N T I A L C O N F L I C T O F

I N T E R E S T

None known.

A C K N O W L E D G E M E N T S

None.

S O U R C E S O F S U P P O R T

External sources of support

South African Medical Research Council SOUTH AFRICA

The Nuffield Trust UK

Internal sources of support

University of the Witwatersrand SOUTH AFRICA




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R E F E R E N C E S

References to studies included in this reviewBlecher 1967 {published data only}

Blecher JA. Aspects of the physiology of decompression and its usage

in the toxaemias of pregnancy and in fetal distress in labour [MD

thesis]. Vol. 1, South Africa: University of the Witwatersrand, 1967:1222.

MacRae 1971 {published data only}

MacRae DJ, Mohamedally SM, Willmott MP. Clinical and en-

docrinological aspects of dysmaturity and the use of intermittent ab-

dominal decompression in pregnancy.J Obstet Gynaecol Br Cmmwlth

1971;78:636641.

Varma 1973 {published data only}

Varma TR, Curzen P. The effects of abdominal decompression on

pregnancy complicated by the small-for-dates fetus.J ObstetGynaecol

Br Cmmwlth1973;80:10861094.

Additional referencesClarke 1999

Clarke M, Oxman AD, editors. Cochrane Reviewers Handbook 4.0

[updatedJuly 1999]. In: ReviewManager(RevMan) [Computer pro-gram]. Version 4.0. Oxford, England: The Cochrane Collaboration,

1999.

Hofmeyr 1989

Hofmeyr GJ. Abdominal decompression during pregnancy. In:

ChalmersI, EnkinMW, KeirseMJNCeditor(s).Effective Care in Preg-

nancy and Childbirth. Oxford: Oxford University Press, 1989:647

652.

T A B L E S

Characteristics of included studies

Study Blecher 1967

Methods Alternation.

Participants Women with pre-eclampsia, essential hypertension or chronic nephritis.

Interventions Women who received abdominal decompression compared with control group.

Outcomes Unchanged or worsening pre-eclampsia; induction of labour; low birthweight; perinatal mortality.

Notes Assessment of pre-eclampsia as unchanged or worsening somewhat subjective.

Allocation concealment C Inadequate

Study MacRae 1971Methods Selected at random, method not specified.

Participants Women with fetuses estimated to be small for gestational age and urinary oestriol levels below the normal

range.

Interventions Participants were allocated either to receive repeated abdominal decompression, or to act as controls.

Outcomes Urinary oestriol levels; perinatal mortality.




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Notes Reported significantly greater urinary oestriol increase with abdominal decompression, but data not given.

Allocation concealment C Inadequate

Study Varma 1973

Methods Alternation. Allocation of 7 women from each group changed because of non-acceptance of abdominaldecompression.

Participants Women with clinically small for dates fetuses and biparietal diameters below the 10th percentile.

Interventions Women who received abdominal decompression compared with control group.

Outcomes Induction of labour; induction of labour for placental insufficiency; fetal distress in labour; low birthweight;

Apgar score


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Authors Hofmeyr GJ

Contribution of author(s) GJH prepared and maintains the review.

Issue protocol first published 1996/2

Review first published 1996/2

Date of most recent amendment 22 February 2006

Date of most recent

SUBSTANTIVE amendment

12 February 1996

Whats New 25 October 2004: Search updated. No new trials identified.

27 January 2004: Search updated. No new trials identified.

Date new studies sought but

none found

25 October 2004

Date new studies found but not

yet included/excluded

Information not supplied by author

Date new studies found and

included/excluded


Date authors conclusions

section amended


Contact address Prof G Justus Hofmeyr

Director/Hon. Professor, Effective Care Research Unit

Department of Obstetrics and Gynaecology, East London Hospital ComplexUniversity of the Witwatersrand, University of Fort Hare, Eastern Cape Department of

Health

Frere and Cecilia Makiwane Hospitals

Private Bag X 9047

East London

Eastern Cape

5200

SOUTH AFRICA

E-mail: [email protected]

Tel: +27 43 7092483

Fax: +27 43 7092483

DOI 10.1002/14651858.CD000004

Cochrane Library number CD000004

Editorial group Cochrane Pregnancy and Childbirth Group

Editorial group code HM-PREG




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G R A P H S A N D O T H E R T A B L E S

Analysis 01.01. Comparison 01 Abdominal decompression for suspected fetal compromise/pre-eclampsia,

Outcome 01 Unchanged or worsening pre-eclampsia

Review: Abdominal decompression for suspected fetal compromise/pre-eclampsia

Comparison: 01 Abdominal decompression for suspected fetal compromise/pre-eclampsia

Outcome: 01 Unchanged or worsening pre-eclampsia

Study Treatment Control Relative Risk (Fixed) Weight Relative Risk (Fixed)

n/N n/N 95% CI (%) 95% CI

Blecher 1967 8/42 20/38 100.0 0.36 [ 0.18, 0.72 ]

Total (95% CI) 42 38 100.0 0.36 [ 0.18, 0.72 ]

Total events: 8 (Treatment), 20 (Control)

Test for heterogeneity: not applicable

Test for overall effect z=2.88 p=0.004

0.1 0.2 0.5 1 2 5 10


Outcome 02 Induction of labour (all indications)



Outcome: 02 Induction of labour (all indications)


n/N n/N 95% CI (%) 95% CI

Blecher 1967 25/80 22/80 34.4 1.14 [ 0.70, 1.84 ]

Varma 1973 37/70 42/70 65.6 0.88 [ 0.66, 1.18 ]

Total (95% CI) 150 150 100.0 0.97 [ 0.75, 1.25 ]

Total events: 62 (Treatment), 64 (Control)Test for heterogeneity chi-square=0.83 df=1 p=0.36 I =0.0%


0.1 0.2 0.5 1 2 5 10




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Outcome 03 Induction for placental insufficiency



Outcome: 03 Induction for placental insufficiency


n/N n/N 95% CI (%) 95% CI

Varma 1973 20/70 27/70 100.0 0.74 [ 0.46, 1.19 ]

Total (95% CI) 70 70 100.0 0.74 [ 0.46, 1.19 ]




0.1 0.2 0.5 1 2 5 10


Outcome 04 Fetal distress in labour



Outcome: 04 Fetal distress in labour


n/N n/N 95% CI (%) 95% CI

Varma 1973 10/70 27/70 100.0 0.37 [ 0.19, 0.71 ]

Total (95% CI) 70 70 100.0 0.37 [ 0.19, 0.71 ]




0.1 0.2 0.5 1 2 5 10




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Outcome 05 Low birthweight



Outcome: 05 Low birthweight


n/N n/N 95% CI (%) 95% CI

Blecher 1967 40/84 55/80 49.3 0.69 [ 0.53, 0.91 ]

Varma 1973 18/70 58/70 50.7 0.31 [ 0.21, 0.47 ]

Total (95% CI) 154 150 100.0 0.50 [ 0.40, 0.63 ]


Test for heterogeneity chi-square=10.83 df=1 p=0.0010 I =90.8%

Test for overall effect z=6.01 p


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Outcome 07 Perinatal mortality



Outcome: 07 Perinatal mortality


n/N n/N 95% CI (%) 95% CI

Blecher 1967 10/84 24/87 70.2 0.43 [ 0.22, 0.85 ]

MacRae 1971 1/28 2/28 6.0 0.50 [ 0.05, 5.20 ]

Varma 1973 2/70 8/70 23.8 0.25 [ 0.06, 1.14 ]

Total (95% CI) 182 185 100.0 0.39 [ 0.22, 0.71 ]


Test for heterogeneity chi-square=0.46 df=2 p=0.80 I =0.0%


0.1 0.2 0.5 1 2 5 10


Outcome 08 Urinary oestriol increase mg per week



Outcome: 08 Urinary oestriol increase mg per week

Study Treatment Control Weighted Mean Difference (Fixed) Weighted Mean Difference (Fixed)

N Mean(SD) N Mean(SD) 95% CI 95% CI

Varma 1973 70 1.68 (1.21) 70 0.91 (0.74) 0.77 [ 0.44, 1.10 ]

-10.0 -5.0 0 5.0 10.0


Outcome 09 Fetal biparietal diameter increase mm per week



Outcome: 09 Fetal biparietal diameter increase mm per week



Varma 1973 70 2.08 (0.36) 70 1.49 (0.71) 0.59 [ 0.40, 0.78 ]

-10.0 -5.0 0 5.0 10.0




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Outcome 10 Birthweight



Outcome: 10 Birthweight



MacRae 1971 28 2800.00 (591.00) 28 2296.00 (364.00) 504.00 [ 246.91, 761.09 ]

-10.0 -5.0 0 5.0 10.0



abdominal decompression for suspected fetal compromise pre-eclampsia

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