Ductal Flow Ratio as Measure of Transition in Preterm Infants After Birth: A Pilot Study

Emma Brouwer*, Ronny Knol, Nathan D. Hahurij, Stuart B. Hooper, Arjan B. Te Pas, Arno A.W. Roest

*Corresponding author for this work

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Background: Cardiovascular changes during the transition from intra- to extrauterine life, alters the pressure gradient across the ductus arteriosus (DA). DA flow ratio (R-L/L-R) has been suggested to reflect the infant's transitional status and could potentially predict neonatal outcomes after preterm birth. Aim: Determine whether DA flow ratio correlates with oxygenation parameters in preterm infants at 1 h after birth. Methods: Echocardiography was performed in preterm infants born <32 weeks gestational age (GA), as part of an ancillary study. DA flow was measured at 1 h after birth. DA flow ratio was correlated with FiO2, SpO2, and SpO2/FiO2 (SF) ratio. The DA flow ratio of infants receiving physiological-based cord clamping (PBCC) or time-based cord clamping (TBCC) were compared. Results: Measurements from 16 infants were analysed (median [IQR] GA 29 [27–30] weeks; birthweight 1,176 [951–1,409] grams). R-L DA shunting was 16 [17–27] ml/kg/min and L-R was 110 [81–124] ml/kg/min. The DA flow ratio was 0.18 [0.11–0.28], SpO2 94 [93–96]%, FiO2 was 23 [21–28]% and SF ratio 4.1 [3.3–4.5]. There was a moderate correlation between DA flow ratio and SpO2 [correlation coefficient (CC) −0.415; p = 0.110], FiO2 (CC 0.384; p = 0.142) and SF ratio (CC −0.356; p = 0.175). There were no differences in DA flow measurements between infants where PBBC or TBCC was performed. Conclusion: In this pilot study we observed a non-significant positive correlation between DA flow ratio at 1 h after birth and oxygenation parameters in preterm infants.

Original languageEnglish
Article number668744
JournalFrontiers in Pediatrics
Publication statusPublished - 19 Jul 2021

Bibliographical note

Funding Information:
AT was the recipient of a Vidi grant, The Netherlands Organisation for Health Research and Development (ZonMw), part of the Innovational Research Incentives Scheme Veni-Vidi-Vici (NWOVidi 2015/2016).

Publisher Copyright:
© Copyright © 2021 Brouwer, Knol, Hahurij, Hooper, Te Pas and Roest.

Research programs

  • EMC MM-03-54-04-A


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