Related Experiment Video
Updated: Jul 16, 2026
In utero Measurement of Heart Rate in Mouse by Noninvasive M-mode Echocardiography
Published on: November 22, 2013
Heart rate variability in the fetus: a comparison of measures
Peter Van Leeuwen1, Silke Lange, Daniel Geue
1Department of Biomagnetism, Grönemeyer Institute for Microtherapy, Bochum, Germany. petervl@microtherapy.de
Insights
Fetal heart rate variability (HRV) measures, assessed using fetal magnetocardiography, show clear dependencies on gestational age and interdependencies within domains. Standard deviation, high frequency band, and approximate entropy adequately describe fetal HRV.
Area of Science:
- Perinatal Medicine
- Cardiology
- Biomedical Engineering
Background:
- Cardiotocography (CTG) is standard for fetal surveillance but lacks accuracy for detailed fetal heart rate variability (HRV) analysis.
- Standard HRV quantification methods are rarely applied to prenatal assessments due to limitations in CTG accuracy.
- The interdependency of standard HRV measures in the prenatal period remains largely unexplored.
Purpose of the Study:
- To investigate standard heart rate variability (HRV) measures in healthy fetuses using fetal magnetocardiography (FMCG).
- To analyze the dependency of HRV measures on gestational age and interdependency among different HRV metrics.
- To identify key HRV measures for adequate prenatal assessment.
Main Methods:
- Fetal magnetocardiography (FMCG) was used to obtain fetal electrocardiogram (fECG) equivalents.
- Ten standard HRV measures were analyzed from 60 five-minute RR interval time series.
- Data were acquired from a homogenous group of 20 healthy fetuses between the 16th and 40th week of gestation.
Main Results:
- Regression analysis revealed significant dependencies of time, frequency, and complexity domain HRV measures on gestational age and mean RR interval.
- Correlation analysis demonstrated strong interdependencies among HRV measures, particularly within their respective domains.
- Standard deviation (time domain), high frequency band (frequency domain), and approximate entropy (complexity) were identified as key measures for describing fetal HRV.
Conclusions:
- Fetal heart rate variability (HRV) analysis using FMCG provides insights into fetal well-being.
- Different characteristics of fetal HRV are captured by various analytical domains.
- Standard HRV measures, when accurately acquired, can be effectively utilized for prenatal assessment.
Background:
In fetal surveillance, fetal heart rate changes are assessed using cardiotocography (CTG). Standard procedures used in the quantification of heart rate variability (HRV) are seldom applied as CTG does not deliver beat interval durations with the same accuracy as the electrocardiogram (ECG). Thus little is known about the interdependency of standard HRV measures prenatally.
Materials And Methods:
Using fetal magnetocardiography (FMCG: the magnetic equivalent of the fetal ECG), we investigated standard HRV measures in a homogenous group of 20 healthy fetuses. Ten HRV measures were analyzed in 60 five-minute RR interval time series derived from FMCG acquisitions (16th-40th week of gestation).
Results:
Using regression analysis, we found a clear dependency on gestational age and mean RR interval for measures from the time and frequency domains as well as for a measure for complexity. Correlation analysis revealed a strong interdependency of the measures, in particular within the specific domains. An adequate description of fetal HRV may be achieved using the standard deviation from the time domain, the high frequency band (0.15-0.40 Hz) from the frequency domain and approximate entropy as a complexity measure.
Conclusion:
The results indicate that different characteristics of fetal HRV are embedded in the different domains.
Related Concept Videos
01:14Fetal Circulation
Two umbilical arteries transport blood from the fetus to the placenta. At the placenta, the blood absorbs oxygen and nutrients while simultaneously eliminating waste products. This oxygen-enriched and nutrient-rich blood then returns to the fetus through one...
01:30Factors Influencing Heart Rate
Let us explore the significant factors affecting heart rate, including age, body temperature, posture, acute pain, chemical influences,...
01:25Correlation between ECG and Cardiac Cycle
A cardiac action potential originates in the SA node and spreads throughout the atria and the AV node in approximately 0.03 seconds. This results in the P wave in an ECG and triggers atrial contraction. The action potential is then briefly slowed at the AV node, allowing the atria to contract and fill the ventricles with blood before...
01:31Regulation of Heart Rates
The SNS increases heart rate through the release of norepinephrine and epinephrine, which act on beta-1 adrenergic receptors in the heart. This action increases the rate of depolarization in the sinoatrial (SA) node, the heart's...
01:19Cardiac Output I:Effect of Heart Rate on Cardiac Output
Cardiac output (CO) refers to the total amount of blood ejected by one of the ventricles in liters per minute (L/min). In a resting adult, CO ranges from 5 to 6 L/min, adjusting according to the body's metabolic requirements.
Effect of Heart Rate on Cardiac Output
Cardiac output adapts to metabolic demands during stress, physical activity, or illness. The autonomic nervous system regulates heart rate via the sinoatrial node. The parasympathetic nervous system decreases heart rate...
01:20Assessment of Ventilation I: Respiratory Rate
A Ventilation assessment is critical for monitoring a patient's health status. Respiration, one of the most accessible vital signs, provides insights into the function of numerous body systems and can indicate serious health issues, such as brainstem injuries from head trauma.
Critical Guidelines for Assessing Ventilation: