Results: The rate and amplitude of spontaneous respiration and arterial blood pressure at rest were the same between the non‐pregnant and pregnant women. However, the baseline R‐R interval was shorter and the respiratory‐synchronized and HF components of the power spectrum of R‐R interval variability were smaller in the pregnant women, indicating a decreased baseline cardiac parasympathetic outflow with mid‐pregnancy. Although a foot bath for 15 min did not significantly affect the systemic hemodynamics and body temperature of both groups, the foot bath reduced the respiratory arrhythmia and the respiratory‐synchronized and HF components of the power spectrum of R‐R interval variability in both groups. The reduction in the respiratory R‐R interval became more prominent in the pregnant group.