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Antenatal cardiotocography for fetal assessment

  • Review
  • Intervention




Cardiotocography (CTG) is a continuous recording of the fetal heart rate obtained via an ultrasound transducer placed on the mother’s abdomen. CTG is widely used in pregnancy as a method of assessing fetal well-being, predominantly in pregnancies with increased risk of complications.


To assess the effectiveness of antenatal CTG (both traditional and computerised assessments) in improving outcomes for mothers and babies during and after pregnancy.

Search methods

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (9 July 2012) and reference lists of retrieved studies.

Selection criteria

Randomised and quasi-randomised trials that compared traditional antenatal CTG with no CTG or CTG results concealed; computerised CTG with no CTG or CTG results concealed; and computerised CTG with traditional CTG.

Data collection and analysis

Two review authors independently assessed eligibility, quality and extracted data.

Main results

Six studies (involving 2105 women) are included. Overall, the included studies were not of high quality, and only two had both adequate randomisation sequence generation and allocation concealment. All studies that were able to be included enrolled only women at increased risk of complications.

Comparison of traditional CTG versus no CTG showed no significant difference identified in perinatal mortality (risk ratio (RR) 2.05, 95% confidence interval (CI) 0.95 to 4.42, 2.3% versus 1.1%, four studies, N = 1627) or potentially preventable deaths (RR 2.46, 95% CI 0.96 to 6.30, four studies, N = 1627), though the meta-analysis was underpowered to assess this outcome. Similarly, there was no significant difference identified in caesarean sections (RR 1.06, 95% CI 0.88 to 1.28, 19.7% versus 18.5%, three trials, N = 1279) nor in the secondary outcomes that were assessed.

There were no eligible studies that compared computerised CTG with no CTG.

Comparison of computerised CTG versus traditional CTG showed a significant reduction in perinatal mortality with computerised CTG (RR 0.20, 95% CI 0.04 to 0.88, two studies, 0.9% versus 4.2%, 469 women). However, there was no significant difference identified in potentially preventable deaths (RR 0.23, 95% CI 0.04 to 1.29, two studies, N = 469), though the meta-analysis was underpowered to assess this outcome. There was no significant difference identified in caesarean sections (RR 0.87, 95% CI 0.61 to 1.24, 63% versus 72%, one study, N = 59) or in secondary outcomes.

Authors' conclusions

There is no clear evidence that antenatal CTG improves perinatal outcome, but further studies focusing on the use of computerised CTG in specific populations of women with increased risk of complications are warranted.








Cochrane Pregnancy and Childbirth Group's Trials Register(2012年7月9日)および検索した試験の文献リストを検索した。






6件の試験(女性2,105名を含む)を組み入れた。全体として、組み入れた試験は高品質ではなく、2件のみ適切なランダム化の手順に従い、割りつけの隠蔵化(コンシールメント)がなされていた。組み入れ可能だった全試験とも、合併症高リスクの女性のみ登録していた。<br /><br />メタアナリシスは当該アウトカムの評価には検出力不足であったが、従来のCTGとCTGなしの比較で周産期死亡率[リスク比(RR) 2.05、95%CI 0.95~4.42、2.3%対1.1%、4件の試験、N = 1,627]または予防可能な死亡例(RR 2.46、95%CI 0.96~6.30、4件の試験、N = 1,627)に有意差を認めなかった。同様に、帝王切開(RR 1.06、95%CI 0.88~1.28, 19.7%対18.5%、3件の試験、N = 1,279)または評価した副次アウトカムに有意差を認めなかった。<br /><br />コンピュータ制御CTGとCTGなしを比較した適格な試験は存在しなかった。<br /><br />コンピュータ制御CTGと従来のCTGとの比較では、コンピュータ制御CTGにより周産期死亡率の有意な低下を認めた(RR 0.20、95%CI 0.04~0.88、2件の試験、0.9%対4.2%、女性469名)。ただし、メタアナリシスは当該アウトカム評価に十分な検出力を有していなかったが、予防可能な死亡例(RR 0.23、95%CI 0.04~1.29、2件の試験、N = 469)に有意差を認めなかった。帝王切開(RR 0.87、95%CI 0.61~1.24、63%対72%、1件の試験、N = 59)または副次アウトカムに有意差を認めなかった。



Plain language summary

Cardiotocography (a form of electronic fetal monitoring) for assessing a baby's well-being in the womb during pregnancy

Some pregnancies can be complicated by a medical condition in the mother (e.g. diabetes or high blood pressure) or a condition that might affect the health or development of the baby. If these babies with potential difficulties could be identified, and if there were effective interventions to improve the outcomes, then an accurate test that could be used during pregnancy could be beneficial. Cardiotocography (CTG) is a continuous electronic record of the baby’s heart rate obtained via an ultrasound transducer placed on the mother’s abdomen. It is sometimes referred to as ‘electronic fetal monitoring’ (EFM). The review looked to see if using CTG during pregnancy might improve outcomes for babies by identifying those with complications. It looked for studies that included women at both increased risk, and at low risk, of complications. The review included six studies with all of the women at increased risk of complications. Four of the studies were undertaken in the 1980s and two in the late 1990s. There were no differences in outcomes identified, although when computerised interpretation of the CTG trace was used, the findings looked promising. However, CTG monitors, associated technologies and the way midwives and obstetricians care for women with different complications in pregnancy have changed over the years. This means that more studies are needed now to see if outcomes for babies at increased risk of complications can be improved with antenatal CTG, particularly computerised CTG.





監  訳: 江藤 宏美, 2014.3.14

実施組織: 厚生労働省委託事業によりMindsが実施した。

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