Objective: Changes in the maternal cardiac autonomic nervous system were assessed in the presence and absence of uterine contractions by analyzing maternal heart-rate variability during labor using wavelet-based power spectral analysis. Methods: We assessed the heart-rate variability in 20 pregnant women during labor and in 15 pregnant women with threatened premature labor with the use of wavelet-based power spectral analysis. Results: There was no significant difference in high-frequency components between the uterine contraction and non-contraction periods. The intensities of the low-frequency and very-low-frequency components during uterine contractions were significantly stronger than the corresponding intensities between uterine contractions. Conclusion: Maternal sympathetic activity was upregulated during uterine contractions, and influenced the very-low-frequency components. This method of analysis may represent a novel means of identifying uterine contractions.

Ueland K, Hansen JM: Maternal cardiovascular dynamics. Labor and delivery under local and caudal analgesia. Am J Obstet Gynecol 1969;103:8–18.
Kjeldsen J: Hemodynamic investigations during labour and delivery. Acta Obstet Gynecol Scand Suppl 1979;89:1–252.
Robson SC, Dunlop W, Boys RJ, Hunter S: Cardiac output during labour. Br Med J (Clin Res Ed) 1987;295:1169–1172.
Lee W, Rokey R, Miller J, Cotton DB: Maternal hemodynamic effects of uterine contractions by M-mode and pulsed-Doppler echocardiography. Am J Obstet Gynecol 1989;161:974–977.
Hunter S, Robson SC: Adaptation of the maternal heart in pregnancy. Br Heart J 1992;68:540–543.
Henricks CH, Quilligna EJ: Cardiac output during labor. Am J Obstet Gynecol 1956;71:953–972.
Hales S: Statistical essays; in Haemastaticks. London, Innings & Manby, 1733.
Kimura Y, Okamura K, Watanabe T, Murotsuki J, Suzuki T, Yano M, Yajima A: Power spectral analysis for autonomic influences in heart rate and blood pressure variability in fetal lambs. Am J Physiol 1996;271:H1333–H1339.
Divon MY, Winkler H, Yeh SY, Platt LD, Langer O, Merkatz IR: Diminished respiratory sinus arrhythmia in asphyxiated term infants. Am J Obstet Gynecol 1986;155:1263–1266.
Chaffin DG, Goldberg CC, Reed KL: The dimension of chaos in the fetal heart rate. Am J Obstet Gynecol 1991;165:1425–1429.
Kimura Y, Okamura K, Watanabe T, Yaegashi N, Uehara S, Yajima A: Time-frequency analysis of fetal heartbeat fluctuation using wavelet transform. Am J Physiol 1998;275:H1993–H1999.
Task Force of the European Society of Cardiology and the North American Society of Pacing and Electrophysiology: Heart rate variability: standards of measurement, physiological interpretation and clinical use. Circulation 1996;93:1043–1065.
Ivanov PC, Rosenblum MG, Peng CK, Mietus J, Havlin S, Stanley HE, Goldberger AL: Scaling behaviour of heartbeat intervals obtained by wavelet-based time-series analysis. Nature 1996;383:323–327.
Pichot V, Gaspoz JM, Molliex S, Antoniadis A, Busso T, Roche F, Costes F, Quintin L, Lacour JR, Barthelemy JC: Wavelet transform to quantify heart rate variability and to assess its instantaneous changes. J Appl Physiol 1999;86:1081–1091.
Morlet D, Peyrin F, Desseigne P, Touboul P, Rubel P: Wavelet analysis of high-resolution signal-averaged ECGs in postinfarction patients. J Electrocardiol 1993;26:311–320.
Morlet D, Couderc JP, Touboul P, Rubel P: Wavelet analysis of high-resolution ECGs in post-infarction patients: role of the basic wavelet and of the analyzed lead. Int J Biomed Comput 1995;39:311–325.
Wolf MM, Varigos GA, Hunt D, Sloman JG: Sinus arrhythmia in acute myocardial infarction. Med J Aust 1978;15:52–53.
Task Force of the European Society of Cardiology and the North American Society of Pacing and Electrophysiology: Heart rate variability: standards of measurement, physiological interpretation, and clinical use. Eur Heart J 1996;17:354–381.
Akselrod S, Gordon D, Ubel FA, Shannon DC, Barger AC, Cohen RJ: Power spectrum analysis of heart rate fluctuation: a quantitative probe of beat to beat cardiovascular control. Science 1981;213:220–222.
Pomeranz M, Macaulay RJ, Caudill MA, Kutz I, Adam D, Gordon D, Kilborn KM, Barger AC, Shannon DC, Cohen RJ, Benson M: Assessment of autonomic function in humans by heart rate spectral analysis. Am J Physiol 1985;248:H151–H153.
Malliani A, Pagani M, Lombardi F, Cerutti S: Cardiovascular neural regulation explored in the frequency domain. Circulation 1991;84:482–492.
Cerati D, Schwartz PJ: Single cardiac vagal fiber activity, acute myocardial ischemia, and risk for sudden death. Circ Res 1991;69:1389–1401.
Kamath MV, Fallen EL: Power spectral analysis of heart rate variability: a noninvasive signature of cardiac autonomic function. Crit Rev Biomed Eng 1993;21:245–311.
Rimoldi O, Pierini S, Ferrari A, Cerutti S, Pagani M, Malliani A: Analysis of short-term oscillations of R-R and arterial pressure in conscious dogs. Am J Physiol 1990;258:H967–H976.
Appel ML, Berger RD, Saul JP, Smith JM, Cohen RJ: Beat to beat variability in cardiovascular variables: noise or music? J Am Coll Cardiol 1989;14:1139–1148.
Saul JP: Beat-to-beat variations of heart rate reflect modulation of cardiac autonomic outflow. NIPS 1990;5:32–37.
Elkayam U, Gleicher N: Hemodynamic and cardiac function during normal pregnancy and the puerperium; in Elkayam U, Gleicher N (eds): Cardiac Problems in Pregnancy. New York, Wiley-Liss, 1998, pp 3–19.
Wang L, Zhang W, Zhao Y: The study of maternal and fetal plasma catecholamine levels during pregnancy and delivery. J Perinat Med 1999;27:195–198.
Alehagen S, Wijma K, Lundberg U, Melin B, Wijma B: Catecholamine and cortisol reaction to childbirth. Int J Behav Med 2001;8:50–65.
Hyndman BW, Kitney RI, Sayers BM: Spontaneous rhythms in physiological control systems. Nature 1971;233:339–341.
Taylor JA, Carr DL, Myers CW, Eckberg DL: Mechanisms underlying very-low-frequency RR-interval oscillations in humans. Circulation 1998;98:547–555.
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