title: Non-invasive measurements of ductus arteriosus flow directly after birth.
abstract: OBJECTIVE
  To assess ductus arteriosus (DA) blood flow directly after birth in healthy term infants after elective caesarean section.
  
  
  METHODS
  In healthy term newborns, echocardiography was performed at 2, 5 and 10 min after birth to monitor cardiac output and DA blood flow. Heart rate (HR) was assessed using ECG.
  
  
  METHODS
  The delivery rooms of the Leiden University Medical Center.
  
  
  METHODS
  24 healthy term infants born after a caesarean section were included in this study.
  
  
  RESULTS
  Mean (SD) HR did not change (158 (18) beats per minute (bpm), 5 min (159 (23) bpm) and 10 min (156 (19) bpm). DA diameter decreased from 5.2 (1.3) mm at 2 min to 4.6 (1.3) mm at 5 min (p=0.01) to (3.9 (1.2) mm) (p=0.01) at 10 min. Right-to-left DA shunting was unaltered (median (IQR) 95 (64-154) mL/kg/min to 90 (56-168) mL/kg/min and 80 (64-120) mL/kg/min, respectively (ns)), whereas left-to-right shunting significantly increased between 2 and 5 min (41 (31-70) mL/kg/min vs 67 (37-102) mL/kg/min (p=0.01)) and increased significantly between 2 and 10 min (93 (67-125)) mL/kg/min (p<0.001). Right-to-left/left-to-right shunting ratio decreased significantly from 2.1 (1.4-3.1) at 2 min to 1.4 (1.0-1.8) at 5 min (p<0.0001) and to 0.9 (0.6-1.1) at 10 min (p<0.0001).
  
  
  CONCLUSIONS
  DA shunting changes swiftly from predominantly right-to-left shunting to predominantly left-to-right shunting at 10 min after birth, reflecting differential changes in pulmonary and systemic vascular resistance.
authors: Division of Neonatology, Department of Pediatrics, Leiden University Medical Center, Leiden, The Netherlands.
authors: Jeroen J
authors: JJ
authors: van Vonderen
authors: Division of Neonatology, Department of Pediatrics, Leiden University Medical Center, Leiden, The Netherlands.
authors: Arjan B
authors: AB
authors: te Pas
authors: Department of Gynaecology and Obstetrics, Leiden University Medical Center, Leiden, The Netherlands.
authors: Clara
authors: C
authors: Kolster-Bijdevaate
authors: Department of Gynaecology and Obstetrics, Leiden University Medical Center, Leiden, The Netherlands.
authors: Jan M
authors: JM
authors: van Lith
authors: Division of Pediatric Cardiology, Department of Pediatrics, Leiden University Medical Center, Leiden, The Netherlands.
authors: Nico A
authors: NA
authors: Blom
authors: The Ritchie Centre, Monash Institute for Medical Research, Monash University, Clayton, Victoria, Australia.
authors: Stuart B
authors: SB
authors: Hooper
authors: Division of Pediatric Cardiology, Department of Pediatrics, Leiden University Medical Center, Leiden, The Netherlands.
authors: Arno A W
authors: AA
authors: Roest
mesh_terms: D002302:Cardiac Output / Q000502:physiology; D002585:Cesarean Section; D004373:Ductus Arteriosus / Q000000981:diagnostic imaging / Q000502:physiology*; D015150:Echocardiography, Doppler / Q000379:methods; D005260:Female; D006339:Heart Rate / Q000502:physiology; D006439:Hemodynamics / Q000502:physiology; D006801:Humans; D007231:Infant, Newborn / Q000502:physiology*; D008991:Monitoring, Physiologic / Q000379:methods; D018743:Perinatal Care / Q000379:methods*; D011182:Postoperative Care / Q000379:methods; D011247:Pregnancy; D011651:Pulmonary Artery / Q000000981:diagnostic imaging / Q000502:physiology
keywords: Neonatology; ductus arteriosus; left ventricular output; neonatal transition; right ventricular output