ACTA MEDICA OKAYAMA

Postnatal adaptations of cardiac hemodynamics in infants born vaginally or by caesarean section may be different. These cardiac functions were evaluated by Doppler echocardiography to assess adaptation differences. Cardiac output, heart rate, stroke volume, mean arterial pressure, total systemic vascular resistance, ejection fraction, and ductus arteriosus diameter were determined and compared at 1, 24 and 72 h of life in 22 infants born vaginally (group 1) and 23 born by caesarean section (group 2). One hour after delivery, heart rate, mean blood pressure, and total systemic resistance were found to be higher in group 1 infants (P < 0.01, P < 0.05, P < 0.05 respectively). Stroke-volume measurements were significantly higher in group 2 (P < 0.05). The ejection fraction and cardiac output values were similar in both groups. At 24 and 72 h, no significant differences were observed in measurements of infants born vaginally or by caesarean section. We did not find a parameter negatively affecting healthy newborns in either mode of delivery. However, under pathological conditions affecting the cardiovascular system at 1 h of life, including perinatal infections and hypoxemia, a lower stroke volume, higher heart rate, higher mean blood pressure, and higher peripheral resistance may cause additional work load to the cardiovascular system in infants born vaginally