title: Decreased cardiac parasympathetic nerve activity of pregnant women during foot baths.
abstract: OBJECTIVE
  This study aimed to examine the effect of foot baths on the cardiac parasympathetic outflow of five pregnant (31-32 weeks; mid-pregnancy) women and 16 non-pregnant women.
  
  
  METHODS
  The cardiac parasympathetic outflow was assessed by using the respiratory variability of the R-R interval under controlled breathing according to three different methods: (i) respiratory sinus arrhythmia; (ii) a respiratory-synchronized component of the power spectrum of R-R interval variability with a fast Fourier transform; and (iii) a high-frequency component (HF at 0.15-0.40 Hz) of the power spectrum of R-R interval variability with a maximum entropy method.
  
  
  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.
  
  
  CONCLUSIONS
  A foot bath, used as part of midwives' daily nursing care, is able to decrease the cardiac parasympathetic outflow of pregnant women.
authors.affiliation: Department of Nursing, School of Health Sciences, Kumamoto University, Kuhinji 4-24-1, Kumamoto, Japan. miyazato@kumamoto-u.ac.jp
authors.forename: Kuniko
authors.initials: K
authors.lastname: Miyazato
authors.forename: Kanji
authors.initials: K
authors.lastname: Matsukawa
mesh_terms: D000328:Adult; D001494:Baths; D016022:Case-Control Studies; D005260:Female; D005528:Foot; D006321:Heart / Q000294:innervation*; D006801:Humans; D010275:Parasympathetic Nervous System / Q000502:physiology*; D011247:Pregnancy