ABSTRACT
OBJECTIVE: The maternal stress measurement from the heart rate variability and the fetal stress measurement from the fetal heart rate variability in non-stress test (NST) were conducted and the correlation between two measurements was calculated. METHODS: From June 2004 to August 2004, 30 cases who visited for antenatal care and admitted at our hospital above 27 weeks of pregnancy were analyzed for tests. The test consists of simultaneous 20-minute non-stress test and 5-minute stress test in stable state of supine position. From measurement and analysis of fetal heart rate variability in NST and maternal stress, three factors -- balance of an autonomic nervous system, an activity of a sympathetic nervous system, and an activity of a parasympathetic nervous system -- were calculated and analyzed. RESULTS: A Pearson correlation coefficient of the LF/HF ratio of mother and fetus did not show the high significance for the whole population (whose value was -0.014), but after clustering the population according to the gestational age, LF/HF ratio, norm LF, and norm HF for mothers in 38 weeks of pregnancy showed highly positive correlation -- the values were 0.760 (p-value 0.011), 0.569, and 0.569, respectively; the cluster of mothers in 38 weeks was the largest one in the population. And value of a mother in four different week also showed positive correlation (0.801). CONCLUSION: A noninvasive method for measurement of fetal stress was suggested and positive correlation between maternal stress and fetal stress was observed. Thus positive feedback may be expected by maternal stress relieving methods, such as aroma therapy and psychosocial support, and the possibility and basis for the evaluation of the effectiveness on maternal and fetal stability by prenatal education was settled.