Echocardiographic assessment of systolic time intervals in vaginal and cesarean delivered neonates.

Echocardiographic assessments of fetal and neonatal systolic time intervals were made to determine differences in circulatory changes in 40 neonates delivered vaginally and 30 delivered by elective cesarean section. Left preejection period (LPEP), left ventricular ejection time (LVET), LPEP/LVET, right preejection period (RPEP), right ventricular ejection time (RVET), RPEP/RVET, and heart rate were determined at various time points from antenatal to 120 hours after delivery. There were no significant changes in left systolic time intervals between the two groups at any various time points. However, RPEP and RPEP/RVET values were significantly higher in the cesarean section group than in those in normal vaginal delivery group within 12 hours after delivery. These results suggest that the transient pulmonary hypertension after delivery is prolonged in babies delivered by elective cesarean section.