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

Background: Cardiovascular changes during the transition from intra- to extrauterine life, alters pressure gradient across ductus arteriosus (DA). DA flow ratio (R-L/L-R) has been suggested reflect infant's transitional status and could potentially predict neonatal outcomes after preterm birth. Aim: Determine whether correlates with oxygenation parameters in infants at 1 h Methods: Echocardiography was performed born <32 weeks gestational age (GA), as part of an ancillary study. measured correlated FiO 2 , SpO /FiO (SF) ratio. The receiving physiological-based cord clamping (PBCC) or time-based (TBCC) were compared. Results: Measurements 16 analysed (median [IQR] GA 29 [27–30] weeks; birthweight 1,176 [951–1,409] grams). R-L shunting [17–27] ml/kg/min L-R 110 [81–124] ml/kg/min. 0.18 [0.11–0.28], 94 [93–96]%, 23 [21–28]% SF 4.1 [3.3–4.5]. There a moderate correlation between [correlation coefficient (CC) −0.415; p = 0.110], (CC 0.384; 0.142) −0.356; 0.175). no differences measurements where PBBC TBCC performed. Conclusion: In this pilot study we observed non-significant positive birth infants.