Abstract
Background
Cardiotocography
(sometimes known as electronic fetal monitoring), records changes in the fetal
heart rate and their temporal relationship to uterine contractions. The aim is
to identify babies who may be short of oxygen (hypoxic), so additional
assessments of fetal well-being may be used, or the baby delivered by caesarean
section or instrumental vaginal birth. Objectives
To
evaluate the effectiveness of continuous cardiotocography during labour. I realize
this is an old issue, but it doesn’t seem to have translated into everyday
practice. MM
Search
strategy We searched the
Cochrane Pregnancy and Childbirth Group Trials Register (March 2006), CENTRAL
(The Cochrane Library 2005, Issue 4), MEDLINE (1966 to December 2005), EMBASE
(1974 to December 2005), Dissertation Abstracts (1980 to December 2005) and the
National Research Register (December 2005).
Selection
criteria
Randomised
and quasi-randomised controlled trials involving a comparison of continuous
cardiotocography (with and without fetal blood sampling) with (a) no fetal
monitoring, (b) intermittent auscultation (c) intermittent cardiotocography. Data
collection and analysis
Two
authors independently assessed eligibility, quality and extracted data. Main
results
Twelve
trials were included (over 37,000 women); only two were high quality. Compared
to intermittent auscultation, continuous cardiotocography showed no significant
difference in overall perinatal death rate (relative risk (RR) 0.85, 95%
confidence interval (CI) 0.59 to 1.23, n = 33,513, 11 trials), but was
associated with a halving of neonatal seizures (RR 0.50, 95% CI 0.31 to 0.80, n
= 32,386, nine trials) although no significant difference was detected in
cerebral palsy (RR 1.74, 95% CI 0.97 to 3.11, n = 13,252, two trials). There
was a significant increase in caesarean sections associated with continuous
cardiotocography (RR 1.66, 95% CI 1.30 to 2.13, n =18,761, 10 trials). Women
were also more likely to have an instrumental vaginal birth (RR 1.16, 95% CI
1.01 to 1.32, n = 18,151, nine trials). Data for subgroups of low-risk,
high-risk, preterm pregnancies and high quality trials were consistent with
overall results. Access to fetal blood sampling did not appear to influence the
difference in neonatal seizures nor any other prespecified outcome. Authors'
conclusions
Continuous
cardiotocography during labour is associated with a reduction in neonatal
seizures, but no significant differences in cerebral palsy, infant mortality or
other standard measures of neonatal well-being. However, continuous
cardiotocography was associated with an increase in caesarean sections and
instrumental vaginal births. The real challenge is how best to convey this
uncertainty to women to enable them to make an informed choice without
compromising the normality of labour. |
