Comparison of fetal heart rate baseline estimation by SisPorto 2.01 and a consensus of clinicians.
OBJECTIVE
Fetal heart rate (FHR) baseline estimation is considered one of the most difficult aspects of computer analysis of cardiotocographs, and a pre-requisite for the remaining evaluation. This study aimed at comparing FHR baselines assigned by SisPorto 2.01 with those estimated by a consensus of three clinicians.


METHODS
A prospective evaluation of 300 consecutively acquired FHR tracings was undertaken, 150 from antepartum high-risk pregnancies and 150 from unselected intrapartum cases. Tracings were presented to three experienced clinicians for individual FHR baseline estimation and were processed by the SisPorto 2.01 program. Clinicians were asked to follow a previously described baseline definition, and cases where differences in estimation exceeded 3 bpm were re-evaluated at a consensus meeting. In the remaining cases, the average of the three estimations was considered the consensus value. Agreement between SisPorto 2.01 and the consensus of clinicians was evaluated using the kappa statistic, the proportions of agreement, the intra-class correlation coefficient, and the limits of agreement.


RESULTS
Differences < or =3 bpm occurred in 89% of antepartum and 81% of intrapartum cases. No differences exceeding 10 bpm occurred in the antepartum, while in the intrapartum these were found in 1% of cases. Maximum difference between computer and clinicians was 8 bpm in the antepartum and 15 bpm in the intrapartum. Kappa statistics, proportions of agreement and correlation coefficients in the antepartum were 0.97, 0.97 and 0.98, respectively. In the intrapartum, they were 0.87, 0.89 and 0.95. Limits of agreement were -3.22 and 5.22 in the antepartum (mean difference: 1.0; standard deviation: 2.16) and -6.45 and 7.07 in the intrapartum (mean difference: 0.13; standard deviation: 3.45).


CONCLUSIONS
An excellent agreement was found between SisPorto 2.01 and a consensus of clinicians in estimation of FHR baselines both in the antepartum and in the intrapartum.
Ayres-de-Campos
Diogo
D
Departamento de Ginecologia e Obstetrícia, Faculdade Medicina da Universidade do Porto, Alameda Hernani Monteiro, 4200-319 Porto, Portugal. sisporto@med.up.pt
Bernardes
João
J
D000328:Adult; D015148:Cardiotocography / Q000295:instrumentation*; D032921:Consensus; D003936:Diagnosis, Computer-Assisted / Q000295:instrumentation*; D005260:Female; D006340:Heart Rate, Fetal; D006801:Humans; D009774:Obstetrics; D036801:Parturition; D011247:Pregnancy; D011446:Prospective Studies; D012984:Software