continuous cardiotocography who.doc

8/14/2019 Continuous cardiotocography WHO.doc

1/4

Continuous cardiotocography (CTG) as

a form of electronic monitoring

(EFM) for fetal assessment duringlabour

With the exception of reduction in the incidence of neonatal seizures, there were no

short- or long-term benefits of routine continuous electronic fetal monitoring. The use

of electronic fetal monitoring was associated with significant increases in the rates of

caesarean section and assisted vaginal delivery.

RHL Commentary by ardin !M

"# E$%&ECE 'MMR*

This Cochrane systematic review (! evaluated the effectiveness and safety of

continuous cardiotocography (CT"! (defined as an attempt to produce a continuous

and simultaneous hard-copy recording of the fetal heart rate and uterine contractions

in real-time throughout the woman#s labour for monitoring fetal well being! by

comparing continuous CT" with$ (i! no fetal monitoring% (ii! intermittent auscultation

(&'! of the fetal heart rate with inard stethoscope or hand-held )oppler ultrasound

device% and (iii! intermittent CT".

'n extensive and appropriate literature search, based on the strategy used by theregnancy and Childbirth "roup of the Cochrane Collaboration was performed. The

outcome measures proposed by the authors are those considered to be of ma*or

importance in evaluating electronic monitoring for fetal assessment. The methodology

used for data extraction, analysis and presentation is sound.

' total of + studies involving / women were included in the review. 0leven of

these studies compared continuous CT" with intermittent auscultation% six used

complementary fetal blood sampling. 1ne trial compared continuous CT" with

intermittent CT", in which fetal blood sampling was made available for both groups.

The authors included both randomized and 2uasi-randomized trials in the review,which caused methodological diversity or heterogeneity in the data available for the

review. Three of the trials included only low-ris3 women, five recruited only high-ris3

women, while the other four evaluated women with mixed ris3. 4our of the included

trials had inade2uate allocation concealment, accounting for a total of +/ women,

e2uivalent to half of the total sample size, which may have influenced the overall

results. 5owever, to deal with this problem, the authors performed a subgroup

analysis based on methodological 2uality.

Two methodological issues regarding the current update of the review need to be

mentioned. 4irst, the main difference to the previous version(+! is the inclusion of an

alternate allocation trial that contributes 6 7 low-ris3 women to the continuousCT" versus &' comparison (!% and second, the data from the -arm trial comparing


2/4

continuous CT" with or without fetal scalp sample (6! were handled using an

arbitrary division of the number of controls to avoid double-counting when comparing

women in this group with both experimental groups. These data should also be

interpreted cautiously since controls were divided into two non-randomized groups,

which could wea3en the statistical power and 2uality of the original trial.

. Continuous versus intermittent CT"

8ased on one trial which included 6966 women at low to moderate ris3 for

complications, no significant differences were found between continuous CT" and

intermittent CT" (/!.. 5owever, a trend favourable to intermittent CT" could be

observed for most of the outcomes evaluated in the review (comparison 9/!, including

caesarean section :relative ris3 (;;! .+fetal well being has not improved much over the last decades and interventions

currently in use in developing countries do not differ significantly from those used


3/4

many years ago. Boreover, while continuous CT" is widely used in developed

countries, its use in many under-resourced settings is infre2uent.

+#+# pplicability of the results

1nly one of the included trials was conducted in a developing country. This trialincluded +99 high-ris3 women (all of whom had meconium stained li2uor!. 1nly

unpublished data from this trial were available for the authors of the review and the

authors considered the trial to have an inade2uate concealment of allocation (9!.

The other eleven trials were conducted in developed countries, and most of them

under strictly controlled research protocols. Thus, the results of this review would not

be easily applicable to under-resourced settings, where only a few or no

cardiotocographs are available, personnel is limited in number and training, and

resources for maintenance and consumables are scarce, in which it would be difficult

to replicate the ideal conditions for continuous CT".

+#.# %mplementation of the inter/ention

The use of continuous CT" in under-resourced settings is not recommended on the

basis of the data reviewed here. olicy-ma3ers and health administrators who consider

implementing such a policy should ta3e into account the fact that continuous CT" has

not been shown to have an overall advantage over the other methods assessed and its

introduction would considerably increase the costs of maternal health care. &f

introduced, a careful evaluation or audit after its implementation should be performed.

.# RE'ERCH

'lthough neonatal seizures were significantly decreased by the use of continuous

CT" compared with intermittent auscultation, the factors behind this reduction are not

3nown. To investigate such factors and their potencial long-term conse2uences, trials

with long-term infant follow up are needed.

Boreover, the use of continuous CT" in many hospitals in developing countries, is

not a standard procedure and sometimes is never performed. &nstead, a combination of

intermittent CT", with intermittent auscultation using handheld devices or inard

stethoscope between recording periods is in many cases seen and accepted as standard

practice. This combination allows to maximise the use of the often scarce number ofcardiotocographs and consumables.

Comparisons of continuous versus intermittent CT" did not have sufficient power to

detect differences between groups. 4uture ade2uately powered ;CTs should explore

the possibility of comparing the two abovementioned variations of the method in

moderate to high ris3 patients. This comparison should include total health costs

evaluation ta3ing into consideration machines, consumables and maintenance of the

e2uipment, as well as the need of proper training on the interpretation of results.

;CTs evaluating the performance of continuous CT" compared to &' in low to high-

ris3 pregnancies with regard to long-term outcomes, cerebral palsy and


4/4

neurodevelopmental disability should be encouraged. Baternal and health providersD

views and satisfaction should also be considered.

References

'lfirevic E, )evane ), "yte "BF. Continuous cardiotocography (CT"! as aform of electronic fetal monitoring (04B! for fetal assessment during labour

(Cochrane ;eview!. The Cochrane Database of Systematic Reviews&ssue ,

+99%Chichester, @G$ Hohn Wiley I ons.

Thac3er 8, troup ), Chang B. Continuous electronic heart rate monitoring

for fetal assessment during labor. The Cochrane Database of Systematic

Reviews&ssue +, +99%Chichester, @G$ Hohn Wiley I ons.

Feveno GH, Cunningham 4", ?elson , ;oar3 BF, Williams BF, "uzic3 ),

et al. ' prospective comparison of selective and universal electronic fetal

monitoring in 6,

continuous cardiotocography who.doc

Documents