Clinical assessment of fetal electrocardiogram monitoring in labour.

OBJECTIVE

To assess the potential clinical value of fetal electrocardiographic (ECG) monitoring in labour.

DESIGN

Descriptive study of the use of ECG waveform analysis during labour and its correlation with other indices of fetal and neonatal well-being.

SETTING

Teaching hospital in Oxford.

SUBJECTS: 86 high risk pregnancies.

MAIN OUTCOME MEASURES: Suitability of ST Segment Analyser (Cinventa, Sweden) for clinical use; relation between the T/QRS ratio during labour (an index of ST segment and T wave elevation) and intrapartum cardiotocography, umbilical artery pH at birth and Apgar scores; T/QRS ratio trends in labour.

RESULTS

The system was robust and user-friendly. No statistically significant relation was found between T/QRS ratios in labour and FHR abnormalities in the cardiotocograph. There was a weak relation between T/QRS ratios and umbilical artery acidosis: at a cervical dilatation of 4 cm, the Spearman rank correlation of the mean T/QRS ratio with umbilical artery actual base deficit was r = -0.31, 0.05 greater than P greater than 0.01. The correlation of T/QRS with the umbilical artery pH was not statistically significant, although a trend was present (Spearman rank: r = -0.26, P greater than 0.05). Correlation of the T/QRS ratio with Apgar scores at 1 and at 5 min was not statistically significant. Only 3 of 16 infants with an Apgar score of less than 7 at 1 min had a mean T/QRS ratio above 0.25 at any time during labour.

CONCLUSION

Further research is necessary before a decision can be made whether this new method of fetal monitoring should be introduced into clinical practice.