Relation of fetal heart rate signals with unassignable baseline to poor neonatal state at birth
Journal
Medical and Biological Engineering and Computing
Journal Volume
50
Journal Issue
7
Pages
717-725
Date Issued
2012
Author(s)
Abstract
Electronic fetal heart rates (FHR) are used to monitor fetal health during labour. The paper records are visually assessed by clinicians, but automated alternatives are being developed. Interpretation, visual or computerised, depends on assigning a baseline to identify key features such as accelerations and decelerations. However, when the FHR is unstable the baseline may be unassignable, making conventional analysis unreliable. Such instability may reflect on fetal health. If true, these segments should not be discarded but quantified, for which we have developed a numerical method. In 7,568 labours, the association between unassignable baseline and umbilical arterial blood pH ? 7.05 at birth (evidence of poor health) was studied retrospectively. We found a consistent increase of the risk for acidaemia with longer intervals of unassignable baseline. This is detectable at the end of the first stage of labour, but stronger at the end of the second stage: in the last 30 min of labour, the odds ratios (with respect to baseline assignable throughout this period) increased from 1.99 (15 min unassignable) to 4.9 (30 min unassignable). Computerised analysis of the FHR becomes unreliable when the baseline cannot be assigned; however, this pattern is itself a pathological feature associated with acidaemia at birth. ? International Federation for Medical and Biological Engineering 2012.
Subjects
Acidaemia
Arterial blood
Computer analysis
Fetal heart rate
Key feature
Odds ratios
Fetal monitoring
Health
Neonatal monitoring
acidosis
article
female
fetus heart rate
fetus monitoring
human
labor
methodology
newborn
physiology
pregnancy
prognosis
retrospective study
signal processing
Acidosis
Female
Fetal Monitoring
Heart Rate, Fetal
Humans
Infant, Newborn
Labor, Obstetric
Pregnancy
Prognosis
Retrospective Studies
Signal Processing, Computer-Assisted
Type
journal article