Comparison of the effects of antenatal magnesium sulphate and ritodrine exposure on circulatory adaptation in preterm infants

• Published in: Clinical physiology and functional imaging Vol. 22; no. 1; pp. 13 - 17
• Main Authors: Rantonen, T.H., Grönlund, J.U., Jalonen, J.O., Ekblad, U.U., Kääpä, P.O., Kero, P.O., Välimäki, I. A.T.
• Format: Journal Article
• Language: English
• Published: Oxford UK Blackwell Science Ltd 01-01-2002; Blackwell Science
• Subjects: Adaptation, Physiological - drug effects; Aging - physiology; autonomic nervous system; Biological and medical sciences; Blood Circulation - drug effects; Blood Circulation - physiology; Blood Pressure - drug effects; blood pressure variability; Cardiovascular system; Fetus - drug effects; Heart Rate - drug effects; heart rate variability; Hemodynamics - drug effects; Humans; Infant, Newborn; Infant, Premature; Magnesium Sulfate - therapeutic use; magnesium sulphate; Medical sciences; Miscellaneous; Pharmacology. Drug treatments; power spectrum; Ritodrine - therapeutic use; Tocolytic Agents - therapeutic use; Heart; Premature; Agonist; Cardiovascular control; Variability; β2-Adrenergic receptor; β-Adrenergic receptor agonist; Infant; Anticonvulsant; Mother; Autonomic nervous system; Respiratory distress; Blood pressure; Human; Magnesium sulfate; Respiratory disease; Muscle relaxant; Biological activity; Pregnancy; Heart rate; Newborn diseases; Treatment; Ritodrine; Circulatory system; Hemodynamics
• ISSN: 1475-0961; 1475-097X
• DOI: 10.1046/j.1475-097X.2002.00387.x

We examined the effects of maternal magnesium sulphate (MgSO4) and ritodrine treatments on the autonomic cardiovascular control in preterm neonates with respiratory distress syndrome during the first 2 days of life. Serial measurements of heart rate (HR), blood pressure (BP) and respirogram were performed during the first 2 days of life in 28 preterm infants below 33 weeks of gestation with antenatal exposure to MgSO4 (n=13) or ritodrine (n=15), and in 12 non‐exposed preterm controls. Spectral analysis was used for the quantification of HR and BP variability. Although antenatal MgSO4 exposure had no effect on HR or the systolic, diastolic or mean BP, it was associated with significant decreased beat‐to‐beat changes in BP. In contrast, ritodrine exposure had no consistent effects on the autonomic cardiovascular control during the first 2 days of life. Our data suggest that maternal MgSO4 treatment decreases the neonatal high frequency changes in BP. This early vascular stabilizing effect of antenatal MgSO4 exposure may contribute to a lowered risk of cerebral vascular catastrophes, in the vulnerable areas of the brain, among the preterm infants with respiratory distress syndrome.