Which nervous system controls fetal heart rate (FHR) variability?

Fetal heart rate (FHR) variability is primarily regulated by the autonomic nervous system, which includes both the sympathetic and parasympathetic branches. The sympathetic nervous system increases heart rate and influences cardiac output, while the parasympathetic nervous system, primarily mediated by the vagus nerve, slows the heart rate and contributes to FHR variability.

This balance between the two systems allows for dynamic regulation of the fetal heart rate in response to various stimuli and environmental changes. Healthy FHR variability indicates a well-functioning autonomic nervous system and good fetal health, as it reflects the ability of the fetus to respond to internal and external factors.

Understanding the interaction between the sympathetic and parasympathetic nervous systems is crucial in monitoring fetal well-being during labor and delivery. Therefore, recognizing that both systems contribute to the control of FHR variability emphasizes the complexity of fetal heart rate regulation and the importance of a balanced autonomic response.