Neonatal Resuscitation with an Intact Cord: Current and Ongoing Trials

Extrauterine Placental Perfusion and Oxygenation in Infants With Very Low Birth Weight: A Randomized Clinical Trial

Importance

An extrauterine placental perfusion (EPP) approach for physiological-based cord clamping (PBCC) may support infants with very low birth weight (VLBW) during transition without delaying measures of support.

Objective

To test whether EPP in resuscitation of infants with VLBW results in higher hematocrit levels, better oxygenation, or improved infant outcomes compared with delayed cord clamping (DCC).

Design, Setting, and Participants

This nonblinded, single-center randomized clinical trial was conducted at a tertiary care neonatal intensive care unit. Infants with a gestational age greater than 23 weeks and birth weight less than 1500 g born by cesarean delivery between May 2019 and June 2021 were included. Data were analyzed from October through December 2021.

Intervention

Prior to cesarean delivery, participants were allocated to receive EPP or DCC. In the EPP group, infant and placenta, connected by an intact umbilical cord, were detached from the uterus and transferred to the resuscitation unit. Respiratory support was initiated while holding the placenta over the infant. The umbilical cord was clamped when infants showed regular spontaneous breathing, stable heart rates greater than 100 beats/min, and adequate oxygen saturations. In the DCC group, cords were clamped 30 to 60 seconds after birth before infants were transferred to the resuscitation unit, where respiratory support was started.

Main Outcomes and Measure

The primary outcome was the mean hematocrit level in the first 24 hours after birth. Secondary prespecified outcome parameters comprised oxygenation during transition and short-term neonatal outcome.

Results

Among 60 infants randomized and included, 1 infant was excluded after randomization; there were 29 infants in the EPP group (mean [SD] gestational age, 27 weeks 6 days [15.0 days]; 14 females [48.3%]) and 30 infants in the DCC group (mean [SD] gestational age, 28 weeks 1 day [17.1 days]; 17 females [56.7%]). The mean (SD) birth weight was 982.8 (276.6) g and 970.2 (323.0) g in the EPP and DCC group, respectively. Intention-to-treat analysis revealed no significant difference in mean hematocrit level (mean difference [MD], 2.1 percentage points; [95% CI, -2.2 to 6.4 percentage points]). During transition, infants in the EPP group had significantly higher peripheral oxygen saturation as measured by pulse oximetry (adjusted MD at 5 minutes, 15.3 percentage points [95% CI, 2.0 to 28.6 percentage points]) and regional cerebral oxygen saturation (adjusted MD at 5 minutes, 11.3 percentage points [95% CI, 2.0 to 20.6 percentage points]). Neonatal outcome parameters were similar in the 2 groups.

Conclusions and Relevance

This study found that EPP resulted in similar hematocrit levels as DCC, with improved cerebral and peripheral oxygenation during transition. These findings suggest that EPP may be an alternative procedure for PBCC in infants with VLBW.

Trial Registration

ClinicalTrials.gov Identifier: NCT03916159.

Cord clamping - 'hold on a minute' is not enough, and sample your blood gases while waiting

There is confusion regarding the dynamics of the umbilical cord circulation and the concomitant placental transfusion. How long does it continue, and at what rate? These questions remain an enigma for many. In this article we will address some common misconceptions about the management of cord circulation, try to explain why there is a lack of clarity, and call in to question the conclusions from an influential meta-analysis and a recently published guideline on cord clamping. We will do that partly by reviewing the rather extensive literature published on the subject over the past 50 to 70 years, which is easily forgotten, but worth considering. In this review, we will also address the important subject of why and how to sample cord blood correctly and to interpret umbilical gases with a sustained cord circulation, which is a crucial part of our ongoing multicenter study 'Sustained cord circulation And Ventilation', the SAVE-study.

Respiratory management in the premature neonate

INTRODUCTION

Advances in neonatal care have made possible the increased survival of extremely preterm infants. Even though there is widespread recognition of the harmful effects of mechanical ventilation on the developing lung, its use has become imperative in the management of micro-/nano-preemies. There is an increased emphasis on the use of less-invasive approaches such as minimally invasive surfactant therapy and non-invasive ventilation that have been proven to result in improved outcomes.

AREAS COVERED

Here, we review the evidence-based practices surrounding the respiratory management of extremely preterm infants including delivery room interventions, invasive and non-invasive ventilation approaches, and specific ventilator strategies in respiratory distress syndrome and bronchopulmonary dysplasia. Adjuvant relevant respiratory pharmacotherapies used in preterm neonates are also discussed.

EXPERT OPINION

Early use of non-invasive ventilation and use of less invasive surfactant administration are key strategies in the management of respiratory distress syndrome in preterm infants. Ventilator management in bronchopulmonary dysplasia must be tailored according to the individual phenotype. There is strong evidence to start caffeine early to improve respiratory outcomes, but evidence is lacking on the use of other pharmacological agents in preterm neonates, and an individualized approach has to be considered for their use.

Transitional circulation and hemodynamic monitoring in newborn infants

Transitional circulation is normally transient after birth but can vary markedly between infants. It is actually in a state of transition between fetal (in utero) and neonatal (postnatal) circulation. In the absence of definitive clinical trials, information from applied physiological studies can be used to facilitate clinical decision making in the presence of hemodynamic compromise. This review summarizes the peculiar physiological features of the circulation as it transitions from one phenotype into another in term and preterm infants. The common causes of hemodynamic compromise during transition, intact umbilical cord resuscitation, and advanced hemodynamic monitoring are discussed. IMPACT: Transitional circulation can vary markedly between infants. There are alterations in preload, contractility, and afterload during the transition of circulation after birth in term and preterm infants. Hemodynamic monitoring tools and technology during neonatal transition and utilization of bedside echocardiography during the neonatal transition are increasingly recognized. Understanding the cardiovascular physiology of transition can help clinicians in making better decisions while managing infants with hemodynamic compromise. The objective assessment of cardio-respiratory transition and understanding of physiology in normal and disease states have the potential of improving short- and long-term health outcomes.

What does the evidence tell us? Revisiting optimal cord management at the time of birth

A newborn who receives a placental transfusion at birth from delayed cord clamping (DCC) obtains about 30% more blood volume than those with immediate cord clamping (ICC). Benefits for term neonates include higher hemoglobin levels, less iron deficiency in infancy, improved myelination out to 12 months, and better motor and social development at 4 years of age especially in boys. For preterm infants, benefits include less intraventricular hemorrhage, fewer gastrointestinal issues, lower transfusion requirements, and less mortality in the neonatal intensive care unit by 30%. Ventilation before clamping the umbilical cord can reduce large swings in cardiovascular function and help to stabilize the neonate. Hypovolemia, often associated with nuchal cord or shoulder dystocia, may lead to an inflammatory cascade and subsequent ischemic injury. A sudden unexpected neonatal asystole at birth may occur from severe hypovolemia. The restoration of blood volume is an important action to protect the hearts and brains of neonates. Currently, protocols for resuscitation call for ICC. However, receiving an adequate blood volume via placental transfusion may be protective for distressed neonates as it prevents hypovolemia and supports optimal perfusion to all organs. Bringing the resuscitation to the mother's bedside is a novel concept and supports an intact umbilical cord. When one cannot wait, cord milking several times can be done quickly within the resuscitation guidelines. Cord blood gases can be collected with optimal cord management.   Conclusion: Adopting a policy for resuscitation with an intact cord in a hospital setting takes a coordinated effort and requires teamwork by obstetrics, pediatrics, midwifery, and nursing.

Placental transfusion: may the "force" be with the baby

Placental transfusion results in a significant decrease in the risk of death for extremely preterm infants. With immediate cord clamping (ICC), these infants can leave up to one-half of their normal circulating in utero blood volume in the placenta. Extremely preterm infants are at highest risk of harm from ICC yet are currently the most likely to receive ICC. Receiving a placenta transfusion provides infants with life-saving components and enhanced perfusion. We present some lesser-known but important effects of placental transfusion. New research reveals that enhanced vascular perfusion causes an organ's endothelial cells to release angiocrine responses to guide essential functions. High progesterone levels and pulmonary artery pressure in the first few hours of life assist with neonatal adaptation. We propose that lack of essential blood volume may be a major factor contributing to inflammation, morbidities, and mortality that preterm infants frequently encounter.

The Assisted Breathing before Cord Clamping (ABC) Study Protocol

Major physiologic changes occur during the transition after birth. For preterm infants, current understanding favours allowing the initial changes to occur prior to cord clamping. Amongst other improved outcomes, systematic reviews have indicated a significant reduction in neonatal blood transfusions following delayed cord clamping. This may be due to a placental transfusion, facilitated by the onset of respiration. If breathing is compromised, placental transfusion may be reduced, resulting in a greater red cell transfusion rate. We designed a randomised trial to investigate whether assisting respiration in this high-risk group of babies would decrease blood transfusion and improve outcomes. The Assisted Breathing before Cord Clamping (ABC) study is a single-centre randomised controlled trial. Preterm infants < 31 weeks that have not established regular breathing before 15 s are randomised to a standard or intervention group. The intervention is intermittent positive pressure ventilation via T piece for 30 s, whilst standard management consists of 30 s of positioning and gentle stimulation. The cord is clamped at 50 s in both groups. The primary outcome is the proportion of infants in each group receiving blood transfusion during the neonatal admission. Secondary outcomes include requirement for resuscitation, the assessment of circulatory status and neonatal outcomes.

Delivery room handling of the newborn

For newly born babies, especially those in need of intervention at birth, actions taken during the first minute after birth, the so-called "Golden Minute", can have important implications for long-term outcomes. Both delivery room handling, including identification of maternal and infant risk factors and provision of effective resuscitation interventions, and antenatal care decisions regarding antenatal steroid administration and mode of delivery, are important and can affect outcomes. Anticipating risk factors for neonates at high risk of requiring resuscitation can decrease time to resuscitation and improve the prognosis. Following a review of maternal and fetal risk factors affecting newborn resuscitation, we summarize the current recommendations for delivery room handling of the newborn. This includes recommendations and rationale for the use of delayed cord clamping and cord milking, heart rate assessment [including the use of electrocardiogram (ECG) electrodes in the delivery room], role of suctioning in newborn resuscitation, and the impact of various ventilatory modes. Oxygenation should be monitored by pulse oximetry. Effects of oxygen and surfactant on subsequent pulmonary outcomes, and recommendations for provisions of appropriate thermoregulatory support are discussed. Regular teaching of delivery room handling should be mandatory.