Computerised analysis of antepartum foetal heart parameters: New reference ranges

Abstract

We selected 4012 cCTG records (one trace for each patient) performed in healthy pregnancies from 30th to 42nd gestational week using foetal heart rate (FHR), short-term variability (STV), long-term irregularity (LTI), Delta, approximate entropy (ApEn), spectral components as low frequency (LF), median frequency (MF), high frequency (HF) and LF/(HF + MF) ratio were analysed. Reference nomograms were created and sensitivity and specificity for the prediction of foetal compromise were calculated which were 90% and 89%, respectively. Changes of cCTG parameters according to gestational week were evaluated: FHR (r = −.65) and LF (r = −.87) showed a statistically significant reduction (p < .05) with gestational age. STV (r = .59), LTI (r = .69), Delta (r = .67), and MF (r = .88) showed a statistically significant increase (p < .05) with gestational age. In contrast, for ApEn (r = −.098), HF (r = .14) and LF/(HF + MF) ratio (r = −.47) a non-statistically significant change was found (p > .05). The identification of reference ranges for cCTG indexes in according to gestational age could provide a more objective examination of cCTG trace.

Keywords:

• Computerised cardiotocography
• antepartum foetal monitoring
• foetal heart rate
• gestational age
• reference ranges

Acknowledgements

All the authors have fulfilled all the conditions required for authorship.

Disclosure statement

There are not conflicts of interest with the topic matter of this manuscript, as described in the instructions to authors.