Antenatal cardiotocogram quality and interpretation using computers

To test the application in practice of computerized fetal heart rate (FHR) analysis in pregnancy.

Randomized distribution of subjects with computerized analysis automatically revealed or concealed.

A district general hospital and a teaching hospital outside London.

2869 pregnant women studied within a year.

Quality and duration of the cardiotocogram; quantitative measurement of FHR variation; number of stillbirths.

With interactive advice to the operator, records were of improved quality (up to 28% without signal loss) with potentially much reduced recording time. The short-term FHR variation measured in the last records before intervention is reported for the first time.

The benefits of using the computers include improvement in record quality and saving of time. In addition, where interpretation depended on estimation of FHR variation there was prima facie evidence of observer misinterpretation; visual analysis was unreliable. A larger trial is now required with more rigorous constraints on intervention.