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Intervention Review

Fetal electrocardiogram (ECG) for fetal monitoring during labour

  1. James P Neilson*

Editorial Group: Cochrane Pregnancy and Childbirth Group

Published Online: 19 JUL 2006

Assessed as up-to-date: 4 SEP 2011

DOI: 10.1002/14651858.CD000116.pub2


How to Cite

Neilson JP. Fetal electrocardiogram (ECG) for fetal monitoring during labour. Cochrane Database of Systematic Reviews 2006, Issue 3. Art. No.: CD000116. DOI: 10.1002/14651858.CD000116.pub2.

Author Information

  1. The University of Liverpool, Department of Women's and Children's Health, Liverpool, UK

*James P Neilson, Department of Women's and Children's Health, The University of Liverpool, First Floor, Liverpool Women's NHS Foundation Trust, Crown Street, Liverpool, L8 7SS, UK. jneilson@liverpool.ac.uk.

Publication History

  1. Publication Status: New search for studies and content updated (no change to conclusions)
  2. Published Online: 19 JUL 2006

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This is not the most recent version of the article. View current version (31 MAY 2013)

 

Abstract

  1. Top of page
  2. Abstract
  3. Plain language summary
  4. 摘要

Background

Hypoxaemia during labour can alter the shape of the fetal electrocardiogram (ECG) waveform, notably the relation of the PR to RR intervals, and elevation or depression of the ST segment. Technical systems have therefore been developed to monitor the fetal ECG during labour as an adjunct to continuous electronic fetal heart rate monitoring with the aim of improving fetal outcome and minimising unnecessary obstetric interference.

Objectives

To compare the effects of analysis of fetal ECG waveforms during labour with alternative methods of fetal monitoring.

Search methods

The Cochrane Pregnancy and Childbirth Group's Trials Register (19 May 2011).

Selection criteria

Randomised trials comparing fetal ECG waveform analysis with alternative methods of fetal monitoring during labour.

Data collection and analysis

Trial quality assessment and data extraction were performed by one review author, without blinding.

Main results

Six trials (16,295 women) were included: five trials of ST waveform analysis (15,338 women) and one trial of PR interval analysis (957 women). In comparison to continuous electronic fetal heart rate monitoring alone, the use of adjunctive ST waveform analysis made no significant difference to primary outcomes: births by caesarean section (risk ratio (RR) 0.99, 95% confidence interval (CI) 0.91 to 1.08), the number of babies with severe metabolic acidosis at birth (cord arterial pH less than 7.05 and base deficit greater than 12 mmol/L) (RR 0.78, 95% CI 0.44 to 1.37, data from 14,574 babies), or babies with neonatal encephalopathy (RR 0.54, 95% CI 0.24 to 1.25). There were, however, on average fewer fetal scalp samples taken during labour (RR 0.61, 95% CI 0.41 to 0.91) although the findings were heterogeneous; there were fewer operative vaginal deliveries (RR 0.90, 95% CI 0.81 to 0.98) and admissions to special care unit (RR 0.89, 95% CI 0.81 to 0.99); there was no statistically significant difference in the number of babies with low Apgar scores at five minutes or babies requiring neonatal intubation. There was little evidence that monitoring by PR interval analysis conveyed any benefit.

Authors' conclusions

These findings provide some modest support for the use of fetal ST waveform analysis when a decision has been made to undertake continuous electronic fetal heart rate monitoring during labour. However, the advantages need to be considered along with the disadvantages of needing to use an internal scalp electrode, after membrane rupture, for ECG waveform recordings.

 

Plain language summary

  1. Top of page
  2. Abstract
  3. Plain language summary
  4. 摘要

Fetal electrocardiogram (ECG) for fetal monitoring during labour

Monitoring the baby's heart using electrocardiography (ECG) plus cardiotocography (CTG) during labour provides some modest help for mothers and babies when continuous monitoring is needed.

Strong uterine contractions during labour reduce the flow of maternal blood to the placenta. The umbilical cord may also be compressed during labour, especially if the membranes are ruptured. Usually the baby has sufficient reserve to withstand this effect but some may become distressed. Electronic heart monitoring may be suggested if the doctors think the baby is not getting enough oxygen during labour. Two different methods may be used. CTG measures the baby's heart rate together with the mother's uterine contractions. An ECG measures the heart's electrical activity and the pattern of the heart beats. This involves an electrode being passed through the woman's cervix and attached to the baby's head. This review of six randomized controlled trials, including a total of 16,295 women, found that monitoring the baby using  ECG plus CTG resulted in fewer blood samples needing to be taken from the baby's scalp, and less surgical assistance with the birth, than with CTG alone. There was no difference in the number of caesarean deliveries and little to suggest that babies were in better condition at birth.

 

摘要

  1. Top of page
  2. Abstract
  3. Plain language summary
  4. 摘要

背景

待產過程中,利用胎兒心電圖進行胎兒監控

待產過程中胎兒缺氧會改變胎兒心電圖的波型變化,特別是PR對RR區間的關係與ST段的上升或下降。胎兒心電圖可成為胎兒監視器的一種輔助工具,共同改善胎兒生產結果,並降低不必要的產科干擾。

目標

比較在待產過程中,以胎兒心電圖波形分析,輔助其他胎兒監控方法的效果。

搜尋策略

搜尋範圍 “the Cochrane Pregnancy and Childbirth Group's Trials Register (April 2006)” 。

選擇標準

以隨機試驗,比較在待產過程中,以胎兒心電圖波形分析,輔助其他胎兒監控方法的結果。

資料收集與分析

由作者進行試驗品質評估與數據選取,屬非盲試驗。

主要結論

四篇文獻共取樣9829人次。與單獨使用胎兒監視器者比較,若加上胎兒心電圖ST波形分析輔助監控胎兒(三篇文獻,8872人次),可減少新生兒發生嚴重酸中毒現象(臍帶血pH值小於7.05,且血鹼不足超過12 mmol/L)(相對危險(RR)0.64,95% C .41 – 1.00,數據來自8801新生兒);雖然新生兒腦病變數很少(17人),卻可減少新生兒腦病變的發生(三篇文獻, R .33,95% CI 0.11 – 0.95);也可減少產中胎兒頭皮採血的需求(三篇文獻, RR 0.76,95% CI 0.67 – 0.86);以及減少器械輔助陰道生產數(三篇文獻, RR 0.87,95% CI 0.78 – 0.96).至於剖腹生產率(三篇文獻,R .97,95% CI 0.84 – 1.11),五分鐘Apgar score低於七分者(三篇文獻, R .80,95% CI 0.56 – 1.14)以及加護病房住院率(三篇文獻, RR 0.90,95% CI 0.75 – 1.08),三者在統計學上並無明顯差異。除了可能減少器械輔助陰道生產的趨勢外(一篇文獻, R .87,95% CI 0.76 – 1.01),沒有證據顯示加上胎兒心電圖PR區間分析輔助監控有實際參考價值。

作者結論

這些文獻提供對於待產過程中,使用胎兒心電圖ST波形分析,輔助持續性胎兒監控的一些正面支持。由於胎兒心電圖的電極必須放在胎兒頭皮上才能記錄波形的關係,只能在破水後操作,因而限制了它的用途。

翻譯人

本摘要由周產期醫學會(Taiwan Society of Perinatology)郭鐘海翻譯。

此翻譯計畫由臺灣國家衛生研究院(National Health Research Institutes, Taiwan)統籌。

總結

待產過程中如有必要,共同使用胎兒心電圖與胎兒監視器,來監控胎兒心臟狀況,對母親與胎兒都是有幫助的。胎兒監視器(CTG)可顯示胎兒心跳速率,胎兒心電圖(ECG)則可顯示胎兒心臟電流活動與心搏形態。胎兒心電圖的電極,必須通過子宮頸而固定在胎兒的頭皮上。回顧這些文獻認為,在待產過程中以胎兒心電圖輔助胎兒監視器監控胎兒狀況,比起單獨使用胎兒監視器,可減少產中胎兒頭皮採血的需求,可減少器械輔助陰道生產的機會,並可提升胎兒出生時血氧濃度的狀況。