Search

Real-time echocardiographic monitoring of blood flow in the ductus venosus and hepatic vein was undertaken during perinatal transition with intact umbilical cord of term born infants. Antegrade flow increased during inspiration, preferentially directing blood flow from the ductus venosus into the right atrium.Objective To investigate the effect of spontaneous breathing on venous return in term infants during delayed cord clamping at birth. Methods Echocardiographic ultrasound recordings were obtained directly after birth in healthy term-born infants. A subcostal view was used to obtain an optimal view of the inferior vena cava (IVC) entering the right atrium, including both the ductus venosus (DV) and the hepatic vein (HV). Colour Doppler was used to assess flow direction and flow velocity. Recordings continued until the umbilical cord was clamped and were stored in digital format for offline analyses. Results Ultrasound recordings were obtained in 15 infants, with a median (IQR) gestational age of 39.6 (39.0-40.9) weeks and a birth weight of 3560 (3195-4205) g. Flow was observed to be antegrade in the DV and HV in 98% and 82% of inspirations, respectively, with flow velocity increasing in 74% of inspirations. Retrograde flow in the DV was observed sporadically and only occurred during expiration. Collapse of the IVC occurred during 58% of inspirations and all occurred caudal to the DV inlet (100%). Conclusion Spontaneous breathing was associated with collapse of the IVC and increased antegrade DV and HV flow velocity during inspiration. Therefore, inspiration appears to preferentially direct blood flow from the DV into the right atrium. This indicates that inspiration could be a factor driving placental transfusion in infants.

Fetal to neonatal transition is characterised by major pulmonary and haemodynamic changes occurring in a short period of time. In the international neonatal resuscitation guidelines, comprehensive recommendations are available on supporting pulmonary transition and delaying clamping of the cord in preterm infants. Recent experimental studies demonstrated that the pulmonary and haemodynamic transition are intimately linked, could influence each other and that the timing of umbilical cord clamping should be incorporated into the respiratory stabilisation. We reviewed the current knowledge on how to incorporate cord clamping into stabilisation of preterm infants and the physiological-based cord clamping (PBCC) approach, with the infant’s transitional status as key determinant of timing of cord clamping. This approach could result in optimal timing of cord clamping and has the potential to reduce major morbidities and mortality in preterm infants.

Aim: To test whether stabilising very preterm infants while performing physiological-based cord clamping (PBCC) is at least as effective as the standard approach of time-based delayed cord clamping (DCC).Methods: A randomised controlled non-inferiority study was performed in two centres from May until November 2018, including preterm infants born below 32 weeks of gestational age. Infants were allocated to PBCC or standard DCC. Infants receiving PBCC were stabilised on a purpose-built resuscitation table with an intact umbilical cord. The cord was clamped when the infant had regular spontaneous breathing, heart rate >= 100 bpm and SpO(2) 90% while using FiO(2) 0.40. In infants receiving DCC, the cord was clamped at 30 60 seconds after birth before they were transferred to the standard resuscitation table for further treatment and stabilisation. Primary outcome was time to reach respiratory stability.Results: Thirty-seven infants (mean gestational age 29+0 weeks) were included. Mean cord clamping time was 5:49 +/- 2:37 min in the PBCC (n = 20) and 1:02 +/- 0:30 min in the DCC group (n = 17). Infants receiving PBCC needed less time to reach respiratory stability (PBCC 5:54 +/- 2:27 min; DCC 7:07 +/- 2:54 min; mean difference corrected for gestational age 1:19 min, 95 degrees 6 CI [3:04 0:27]), showing non-inferiority with the pre-defined limit of 1:15 min. No significant differences between the groups were found for maternal blood loss, postpartum haemorrhage, infant temperature at admission or short-term neonatal outcomes.Conclusion: Stabilisation of very preterm infants with physiological-based cord clamping is at least as effective as with standard DCC.

ObjectivePhysiological-based cord clamping (PBCC) led to a more stable cardiovascular adaptation and better oxygenation in preterm lambs, but in preterm infants, this approach has been challenging. Our aim was to assess the feasibility of PBCC, including patterns of oxygen saturation (SpO2) and heart rate (HR) during stabilisation in preterm infants using a new purpose-built resuscitation table.DesignObservational study.SettingTertiary referral centre, Leiden University Medical Centre, The Netherlands.PatientsInfants born below 35 weeks’ gestational age.InterventionsInfants were stabilised on a new purpose-built resuscitation table (Concord), provided with standard equipment needed for stabilisation. Cord clamping was performed when the infant was stable (HR >100 bpm, spontaneous breathing on continuous positive airway pressure with tidal volumes >4 mL/kg, SpO2 ≥25th percentile and fraction of inspired oxygen (FiO2) ResultsThirty-seven preterm infants were included; mean (SD) gestational age of 30.9 (2.4) weeks, birth weight 1580 (519) g. PBCC was successful in 33 infants (89.2%) and resulted in median (IQR) cord clamping time of 4:23 (3:00–5:11) min after birth. There were no maternal or neonatal adverse events. In 26/37 infants, measurements were adequate for analysis. HR was 113 (81–143) and 144 (129–155) bpm at 1 min and 5 min after birth. SpO2 levels were 58%(49%–60%) and 91%(80%–96%)%), while median FiO2 given was 0.30 (0.30–0.31) and 0.31 (0.25–0.97), respectively.ConclusionPBCC in preterm infants using the Concord is feasible. HR remained stable, and SpO2 quickly increased with low levels of oxygen supply.Trial registration numberNTR6095, results.

IntroductionDuring delayed umbilical cord clamping, the factors underpinning placental transfusion remain unknown. We hypothesised that reductions in thoracic pressure during inspiration would enhance placental transfusion in spontaneously breathing preterm lambs.ObjectiveInvestigate the effect of spontaneous breathing on umbilical venous flow and body weight in preterm lambs.MethodsPregnant sheep were instrumented at 132–133 days gestational age to measure fetal common umbilical venous, pulmonary and cerebral blood flows as well as arterial and intrapleural (IP) pressures. At delivery, doxapram and caffeine were administered to promote breathing. Lamb body weights were measured continuously and breathing was assessed by IP pressure changes.ResultsIn 6 lambs, 491 out of 1117 breaths were analysed for change in body weight. Weight increased in 46.6% and decreased in 47.5% of breaths. An overall mean increase of 0.02±2.5 g per breath was calculated, and no net placental transfusion was observed prior to cord clamping (median difference in body weight 52.3 [−54.9–166.1] g, p=0.418). Umbilical venous (UV) flow transiently decreased with each inspiration, and in some cases ceased, before UV flow normalised during expiration. The reduction in UV flow was positively correlated with the standardised reduction in (IP) pressure, increasing by 109 mL/min for every SD reduction in IP pressure. Thus, the reduction in UV flow was closely related to inspiratory depth.ConclusionsSpontaneous breathing had no net effect on body weight in preterm lambs at birth. UV blood flow decreased as inspiratory effort increased, possibly due to constriction of the inferior vena cava caused by diaphragmatic contraction, as previously observed in human fetuses.

Background: Most preterm infants fail to aerate their immature lungs at birth and need respiratory support for cardiopulmonary stabilization. Cord clamping before lung aeration compromises cardiovascular function. Delaying cord clamping until the lung has aerated may be beneficial for preterm infants by optimizing hemodynamic transition and placental transfusion. A new purpose-built resuscitation table (the Concord) has been designed making it possible to keep the cord intact after preterm birth until the lung is aerated and the infant is respiratory stable and breathing [Physiological-Based Cord Clamping (PBCC)]. The aim of this study is to test the hypothesis whether stabilizing preterm infants by PBCC is at least as effective as the standard approach using time-based Delayed Cord Clamping (DCC). Study design: This is a randomized controlled non-inferiority study including 64 preterm infants born at >32 weeks of gestation. Infants will be randomized to either the PBCC approach or standard DCC. In case of PBCC, infants will be stabilized with an intact umbilical cord and the cord will only be clamped when the infant is considered respiratory stable, defined as the establishment of regular spontaneous breathing, a heart rate =100 bpm and oxygen saturation above 90% while using inspired fraction of oxygen (FiO 2 ) > 0.40. The Concord will be used, which allows giving respiratory support with an intact umbilical cord. In the DCC group infants are clamped first before they are transferred to the standard resuscitation table for further treatment and stabilization. Cord clamping is time-based and delayed at 30-60 s. The primary outcome will be the time to respiratory stability of the infant, starting from birth. Secondary outcomes will include details of stabilization, important clinical outcomes of prematurity and maternal safety outcomes. Discussion: We expect that PBCC using the Concord may reduce major morbidities and mortality in preterm infants. The current study protocol will assess the effectivity of stabilization. Once effectivity of stabilization is confirmed, we will start a large multicenter randomized clinical trial to investigate whether PBCC reduces mortality and morbidity in preterm infants compared to the standard approach. Trial registration: Netherlands Trial Registry NTR7194, registered on April 20th, 2018.

Background: Doxapram has been advocated as a treatment for persistent apnea of prematurity (AOP). Objective: To evaluate the effect of doxapram on long-term neurodevelopmental outcome in preterm infants as its safety still needs to be established. Methods: From a retrospective cohort of preterm infants with a gestational age (GA) Results: Infants treated with doxapram had a lower GA compared to controls. The number of infants with a MDI or PDI Conclusions: This study suggests that doxapram is not associated with an increased risk of ND. These findings need to be confirmed or refuted by a large, well-designed, placebo-controlled randomized trial.