Gestational age and CTG - query bank

Question:  At what gestational age can CTG be started for fetal well being/fetal monitoring?

Please note: the search for this response was carried out over 1 year ago. Eligible users may request an update of the evidence by submitting a new Clinical Query here.

Answer: A Cochrane review of antenatal cardiotocography for fetal assessment (1) found no clear evidence that antenatal CTG improves perinatal outcome. The review included six studies (involving 2105 women). 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. There was insufficient data to compare antenatal CTG testing begun on fetus less than 37 completed weeks' gestation versus antenatal CTG testing begun on fetus 37 or more completed weeks' gestation.


  1. Grivell RM, Alfirevic Z, Gyte GML, Devane D. Antenatal cardiotocography for fetal assessment. Cochrane Database of Systematic Reviews 2010, Issue 1. Art. No.: CD007863. DOI: 10.1002/14651858.CD007863.pub2. Abstract and full text in selected countries. Full text available for Fellows, Members and Trainees through OVID

Search date: June 2010

Classification of evidence levels

Ia Evidence obtained from meta-analysis of randomised controlled trials.

Ib Evidence obtained from at least one randomised controlled trial.

IIa Evidence obtained from at least one well-designed controlled study without randomisation.

IIb Evidence obtained from at least one other type of well-designed quasi-experimental study.

III Evidence obtained from well-designed non-experimental descriptive studies, such as comparative studies, correlation studies and case studies.

IV Evidence obtained from expert committee reports or opinions and/or clinical experience of respected authorities.

This clinical query answer was produced following the clinical query protocol as described here.

The RCOG will not be liable for any special or consequential damages arising from the use or reliance on information contained within the Query Bank.

Date published: 28/06/2010

main menu