RT Journal Article SR Electronic T1 Non-invasive measurements of ductus arteriosus flow directly after birth JF Archives of Disease in Childhood - Fetal and Neonatal Edition JO Arch Dis Child Fetal Neonatal Ed FD BMJ Publishing Group Ltd and Royal College of Paediatrics and Child Health SP F408 OP F412 DO 10.1136/archdischild-2014-306033 VO 99 IS 5 A1 Jeroen J van Vonderen A1 Arjan B te Pas A1 Clara Kolster-Bijdevaate A1 Jan M van Lith A1 Nico A Blom A1 Stuart B Hooper A1 Arno A W Roest YR 2014 UL http://fn.bmj.com/content/99/5/F408.abstract AB Objective To assess ductus arteriosus (DA) blood flow directly after birth in healthy term infants after elective caesarean section. Design 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. Setting The delivery rooms of the Leiden University Medical Center. Patients 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.