Physiologically based cord clamping for infants ≥32+0 weeks gestation: A randomised clinical trial and reference percentiles for heart rate and oxygen saturation for infants ≥35+0 weeks gestation

Thermoregulation for very preterm infants in the delivery room: a narrative review

Abnormal temperature in preterm infants is associated with increased morbidity and mortality. Infants born prematurely are at risk of abnormal temperature immediately after birth in the delivery room (DR). The World Health Organization (WHO) recommends that the temperature of newly born infants is maintained between 36.5-37.5oC after birth. When caring for very preterm infants, the International Liaison Committee on Resuscitation (ILCOR) recommends using a combination of interventions to prevent heat loss. While hypothermia remains prevalent, efforts to prevent it have increased the incidence of hyperthermia, which may also be harmful. Delayed cord clamping (DCC) for preterm infants has been recommended by ILCOR since 2015. Little is known about the effect of timing of DCC on temperature, nor have there been specific recommendations for thermal care before DCC. This review article focuses on the current evidence and recommendations for thermal care in the DR, and considers thermoregulation in the context of emerging interventions and future research directions. IMPACT: Abnormal temperature is common amongst very preterm infants after birth, and is an independent risk factor for mortality. The current guidelines recommend a combination of interventions to prevent heat loss after birth. Despite this, abnormal temperature is still a problem, across all climates and economies. New and emerging delivery room practice (i.e., delayed cord clamping, mobile resuscitation trolleys, early skin to skin care) may have an effect on infant temperature. This article reviews the current evidence and recommendations, and considers future research directions.

Blood pressure and cerebral oxygenation with physiologically-based cord clamping: sub-study of the BabyDUCC trial

BACKGROUND

Cord-clamping strategies may modify blood pressure (BP) and cerebral tissue oxygen saturation (rStO2) immediately after birth.

METHODS

We conducted a sub-study nested within the Baby-Directed Umbilical Cord-Clamping trial. Infants ≥32+0 weeks' gestation assessed as requiring resuscitation were randomly allocated to either physiologically-based cord clamping (PBCC), where resuscitation commenced prior to umbilical cord clamping, or standard care where cord clamping occurred early (ECC). In this single-site sub-study, we obtained additional measurements of pre-ductal BP and rStO2. In a separate observational arm, non-randomised vigorous infants received 2 min of deferred cord clamping (DCC) and contributed data for reference percentiles.

RESULTS

Among 161 included infants, n = 55 were randomly allocated to PBCC (n = 30) or ECC (n = 25). The mean (SD) BP at 3-4 min after birth (primary outcome) in the PBCC group was 64 (10) mmHg compared to 62 (10) mmHg in the ECC group, mean difference 2 mmHg (95% confidence interval -3-8 mmHg, p = 0.42). BP and rStO2 were similar across both randomised arms and the observational arm (n = 106).

CONCLUSION

We found no difference in BP or rStO2 with the different cord clamping strategies. We report reference ranges for BP and rStO2 for late-preterm and full-term infants receiving DCC.

IMPACT

Among late-preterm and full-term infants receiving varying levels of resuscitation, blood pressure (BP, at 3-4 minutes and 6 min) and cerebral tissue oxygen saturation (rStO2) are not influenced by timing of cord clamping in relation to establishment of ventilation. Infants in this study did not require advanced resuscitation, where cord clamping strategies may yet influence BP and rStO2. The reference ranges for BP and rStO2 represent the first, to our knowledge, for vigorous late-preterm and full-term infants receiving deferred cord clamping. rStO2 > 90% (~90th percentile) may be used to define cerebral hyperoxia, for instance when studying oxygen supplementation after birth.

Extended period of ventilation before delayed cord clamping augments left-to-right shunting and decreases systemic perfusion at birth in preterm lambs

Previous studies have suggested that an extended period of ventilation before delayed cord clamping (DCC) augments birth-related rises in pulmonary arterial (PA) blood flow. However, it is unknown whether this greater rise in PA flow is accompanied by increases in left ventricular (LV) output and systemic arterial perfusion or whether it reflects enhanced left-to-right shunting across the ductus arteriosus and/or foramen ovale (FO), with decreased systemic arterial perfusion. Using an established preterm lamb birth transition model, this study compared the effect of a short (∼40 s, n = 11), moderate (∼2 min, n = 11) or extended (∼5 min, n = 12) period of initial mechanical lung ventilation before DCC on flow probe-derived perinatal changes in PA flow, LV output, total systemic arterial blood flow, ductal shunting and FO shunting. The LV output was relatively stable during initial ventilation but increased after DCC, with similar responses in all groups. Systemic arterial flow patterns displayed only minor differences during brief and moderate periods of initial ventilation and were similar after DCC. However, an increase in PA flow was augmented with an extended initial ventilation (P < 0.001), owing to an earlier onset of left-to-right ductal and FO shunting (P < 0.001), and was accompanied by a pronounced reduction in total systemic arterial flow (P = 0.005) that persisted for 4 min after DCC (P ≤ 0.039). These findings suggest that, owing to increased left-to-right shunting and a greater reduction in systemic arterial perfusion, an extended period of ventilation before DCC does not result in greater perinatal circulatory benefits than shorter periods of initial ventilation in the birth transition. KEY POINTS: Previous studies suggest that an extended period of initial ventilation before delayed cord clamping (DCC) augments birth-related rises in pulmonary arterial (PA) blood flow. It is unknown whether this greater rise in PA flow is accompanied by an increased left ventricular output and systemic arterial perfusion or whether it reflects enhanced left-to-right shunting across the ductus arteriosus and/or foramen ovale, with decreased systemic arterial perfusion. Anaesthetized preterm fetal lambs instrumented with central arterial flow probes underwent a brief (∼40 s), moderate (∼2 min) or extended (∼5 min) period of ventilation before DCC. Perinatal changes in left ventricular output were similar in all groups, but extended initial ventilation augmented both perinatal increases in PA flow, owing to earlier onset and greater left-to-right ductal and foramen ovale shunting, and perinatal reductions in total systemic arterial perfusion. Extended ventilation before DCC does not confer a greater perinatal circulatory benefit than shorter periods of initial ventilation.

Combining activity and grimace scores reflects perinatal stability in infants <32 weeks gestational age

BACKGROUND

Over 95% of infants less than 32 weeks gestational age-very preterm infants (VPTI)-require cardiorespiratory support at birth. Clinical condition at birth is assessed by the Apgar score, but the precision and accuracy of activity and grimace has not been evaluated. We hypothesised activity and grimace could predict the level of cardiorespiratory support required for stabilisation.

METHODS

Two hundred twenty-nine videos of VPTI resuscitations at Monash Children's Hospital and The Royal Women's Hospital, Melbourne were evaluated, with 78 videos eligible for assessment. Activity and grimace were scored (0, 1, or 2) by seven consultant neonatologists, with inter-rater reliability assessed. Activity and grimace were correlated with the maximum level of cardiorespiratory support required for stabilisation.

RESULTS

Kendall's Coefficient of Concordance (W) showed strong interobserver agreement for activity (W = 0.644, p < 0.001) and grimace (W = 0.722, p < 0.001). Neither activity nor grimace independently predicted the level of cardiorespiratory support required. Combining activity and grimace showed non-vigorous infants (combined score <2) received more cardiorespiratory support than vigorous (combined score ≥ 2).

CONCLUSION

Scoring of activity and grimace was consistent between clinicians. Independently, activity and grimace did not correlate with perinatal stabilisation. Combined scoring showed non-vigorous infants had greater resuscitation requirements.

IMPACT

Our study evaluates the precision and accuracy of activity and grimace to predict perinatal stability, which has not been validated in infants <32 weeks gestational age. We found strong score agreement between assessors, indicating video review is a practical and precise method for grading of activity and grimace. Combined scoring to allow a dichotomous evaluation of infants as non-vigorous or vigorous showed the former group required greater cardiorespiratory support at birth.

Deciphering Mechanisms of Respiratory Fetal-to-Neonatal Transition in Very Preterm Infants

Rationale: The respiratory mechanisms of a successful transition of preterm infants after birth are largely unknown. Objectives: To describe intrapulmonary gas flows during different breathing patterns directly after birth. Methods: Analysis of electrical impedance tomography data from a previous randomized trial in preterm infants at 26-32 weeks gestational age. Electrical impedance tomography data for individual breaths were extracted, and lung volumes as well as ventilation distribution were calculated for end of inspiration, end of expiratory braking and/or holding maneuver, and end of expiration. Measurements and Main Results: Overall, 10,348 breaths from 33 infants were analyzed. We identified three distinct breath types within the first 10 minutes after birth: tidal breathing (44% of all breaths; sinusoidal breathing without expiratory disruption), braking (50%; expiratory brake with a short duration), and holding (6%; expiratory brake with a long duration). Only after holding breaths did end-expiratory lung volume increase: Median (interquartile range [IQR]) = 2.0 AU/kg (0.6 to 4.3), 0.0 (-1.0 to 1.1), and 0.0 (-1.1 to 0.4), respectively; P < 0.001]. This was mediated by intrathoracic air redistribution to the left and non-gravity-dependent parts of the lung through pendelluft gas flows during braking and/or holding maneuvers. Conclusions: Respiratory transition in preterm infants is characterized by unique breathing patterns. Holding breaths contribute to early lung aeration after birth in preterm infants. This is facilitated by air redistribution during braking/holding maneuvers through pendelluft flow, which may prevent lung liquid reflux in this highly adaptive situation. This study deciphers mechanisms for a successful fetal-to-neonatal transition and increases our pathophysiological understanding of this unique moment in life. Clinical trial registered with www.clinicaltrials.gov (NCT04315636).

Impact of the Timing of Umbilical Cord Clamping on Maternal and Neonatal Outcomes in Saudi Arabia

INTRODUCTION

The optimal time for umbilical cord clamping after delivery has been under debate for several decades. This study aimed to assess the time-dependent effects of umbilical cord clamping on maternal and neonatal outcomes.

METHODS

An observational correlational design was used to recruit 161 pregnant women conveniently. Outcomes were observed and recorded using a structured checklist developed by the authors. Pregnant females aged ≥18 years, with uncomplicated delivery, and who were willing to participate were recruited. Exclusion criteria included stillbirths, newborns with congenital anomalies, newborns too small for their gestational age, intra-uterine growth restriction, nuchal cord, and meconium-stained liquor.

RESULTS

The mean age of the participants was 29.93 ± 6 years. Early clamping (<1 minute) was performed for 93.8% of the participants with a mean of 29.58 ± 18 seconds. Delayed clamping was associated with a decrease in blood loss and the length of hospital stay in addition to an increase in first-minute APGAR score and neonatal temperature (P < 0.05).

CONCLUSIONS

Delayed cord clamping was associated with improved maternal and neonatal outcomes.

Stabilisation and resuscitation with intact cord circulation is feasible using a wide variety of approaches; a scoping review

AIM

This scoping review identified studies on approaches to intact cord resuscitation and/or stabilisation (ICR/S) for neonates delivered by Caesarean section (C-section).

METHODS

A systematic literature search was carried out using the PubMed, Web of Science, Scopus, Cochrane and CINAHL databases to identify papers published in English from inception to 14 November 2022.

RESULTS

We assessed 2613 studies and included 18 from 10 countries, covering 1-125 C-sections: the United States, the United Kingdom, Australia, India, Italy, China, France, The Netherlands, New Zealand and Taiwan. The papers were published from 2014 to 2023, and the majority were randomised controlled trials and observational studies. Different platforms, equipment and staff positions in relation to the operating table were described. Options for resuscitation and stabilisation included different bedding and trolley approaches, and maintaining aseptic conditions was mainly addressed by the neonatal team scrubbing in. Hypothermia was prevented by using warm surfaces, polythene bags and radiant heaters. Equipment was kept easily accessible by mounting it on a trolley or a separate mobile pole.

CONCLUSION

We could not reach definitive conclusions on the optimal method for performing ICR/S during a C-section, due to study variations. However, a number of equipment and management options appeared to be feasible approaches.

Significance of Neonatal Heart Rate in the Delivery Room-A Review

BACKGROUND

Heart rate (HR) is considered the main vital sign in newborns during perinatal transition, with a threshold of 100 beats per minute (bpm), below which, intervention is recommended. However, recent changes in delivery room management, including delayed cord clamping, are likely to have influenced normal HR transition.

OBJECTIVE

To summarize the updated knowledge about the factors, including measurement methods, that influence HR in newborn infants immediately after birth. Additionally, this paper provides an overview of delivery room HR as a prognostic indicator in different subgroups of newborns.

METHODS

We searched PubMed, EMBASE, and Google Scholar with the terms infant, heart rate, delivery room, resuscitation, pulse oximetry, and electrocardiogram.

RESULTS

Seven studies that described HR values in newborn infants immediately after birth were included. Pulse oximetry-derived HR percentiles after immediate cord clamping may not be applicable to the current practice of delayed cord clamping and the increasing use of delivery room electrocardiograms. Mask ventilation may adversely affect HR, particularly in premature and non-asphyxiated infants. Prolonged bradycardia is a negative prognostic factor, especially if combined with hypoxemia in infants <32 weeks of gestation.

CONCLUSIONS

HR assessment in the delivery room remains important. However, the cardiopulmonary transition is affected by delayed cord clamping, gestational age, and underlying conditions.

Heart Rate Changes following Facemask Placement in Infants Born at ≥32+0 Weeks of Gestation

INTRODUCTION

Recent reports have raised concerns of cardiorespiratory deterioration in some infants receiving respiratory support at birth. We aimed to independently determine whether respiratory support with a facemask is associated with a decrease in heart rate (HR) in some late-preterm and term infants.

METHODS

Secondary analysis of data from infants born at ≥32+0 weeks of gestation at 2 perinatal centres in Melbourne, Australia. Change in HR up to 120 s after facemask placement, measured using 3-lead electrocardiography, was assessed every 3 s until 60 s and every 5 s thereafter from video recordings.

RESULTS

In the 15 s after facemask placement, 10/68 (15%) infants had a decrease in mean HR by >10 beats per minute (bpm) compared with their individual baseline mean HR in the 15 s before facemask placement. In 4 (6%) infants, HR decreased to <100 bpm. Nine out of 68 (13%) infants had an increase in mean HR by >10 bpm; 7 of these infants had a baseline HR <120 bpm. In univariable comparisons, the following characteristics were found not to be risk factors for a decrease in HR by >10 bpm: prematurity; type of respiratory support; hypoxaemia; early cord clamping; mode of birth; HR <120 bpm before mask placement. Six out of 63 infants (10%) who had HR ≥120 bpm after facemask placement had a late decrease in HR to <100 bpm between 30 and 120 s after facemask placement.

CONCLUSION

Facemask respiratory support at birth is temporally associated with a decrease in HR in a subset of late-preterm and term infants.

Assisted ventilation prior to umbilical cord clamping: Potential benefits, challenges, and research studies

Delayed cord clamping (DCC) is beneficial for many infants, and the American College of Obstetrics and Gynecology recommends at least 30-60 seconds of DCC for both term and preterm vigorous infants. For newly born infants that are not vigorous, some evidence in animal models suggests that providing assisted ventilation prior to cord clamping (V-DCC) leads to a more stable transition of cerebral, pulmonary and systemic circulation and oxygenation and may confer not only short-term physiologic benefits but perhaps also improvement in clinically important outcomes. This review is based around 7 questions to help the reader understand the physiologic underpinnings and challenges of V-DCC as well as the published and ongoing research studies aimed at determining whether V-DCC is beneficial for preterm or term infants.

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.

Observational study comparing heart rate in crying and non-crying but breathing infants at birth

BACKGROUND

Stimulating infants to elicit a cry at birth is common but could result in unnecessary handling. We evaluated heart rate in infants who were crying versus non-crying but breathing immediately after birth.

METHODS

This was single-centre observational study of singleton, vaginally born infants at ≥33 weeks of gestation. Infants who were crying or non-crying but breathing within 30 s after birth were included. Background demographic data and delivery room events were recorded using tablet-based applications and synchronised with continuous heart rate data recorded by a dry-electrode electrocardiographic monitor. Heart rate centile curves for the first 3 min of life were generated with piecewise regression analysis. Odds of bradycardia and tachycardia were compared using multiple logistic regression.

RESULTS

1155 crying and 54 non-crying but breathing neonates were included in the final analyses. There were no significant differences in the demographic and obstetric factors between the cohorts. Non-crying but breathing infants had higher rates of early cord clamping <60 s after birth (75.9% vs 46.5%) and admission to the neonatal intensive care unit (13.0% vs 4.3%). There were no significant differences in median heart rates between the cohorts. Non-crying but breathing infants had higher odds of bradycardia (heart rate <100 beats/min, adjusted OR 2.64, 95% CI 1.34 to 5.17) and tachycardia (heart rate ≥200 beats/min, adjusted OR 2.86, 95% CI 1.50 to 5.47).

CONCLUSION

Infants who are quietly breathing but do not cry after birth have an increased risk of both bradycardia and tachycardia, and admission to the neonatal intensive care unit.

TRIAL REGISTRATION NUMBER

ISRCTN18148368.

Optimizing cord management for each preterm baby - Challenges of collating individual participant data and recommendations for future collaborative research

The optimal cord management strategy at birth for each preterm baby is still unknown, despite more than 100 randomized controlled trials (RCTs) undertaken on this question. To address this, we brought together all RCTs examining cord management strategies at preterm birth in the iCOMP (individual participant data on COrd Management at Preterm birth) Collaboration, to perform an individual participant data network meta-analysis. In this paper, we describe the trials and tribulations around obtaining individual participant data to resolve controversies around cord clamping, and we derive key recommendations for future collaborative research in perinatology. To reliably answer outstanding questions, future cord management research needs to be collaborative and coordinated, by aligning core protocol elements, ensuring quality and reporting standards are met, and carefully considering and reporting on vulnerable sub-populations. The iCOMP Collaboration is an example of the power of collaboration to address priority research questions, and ultimately improve neonatal outcomes worldwide.

Perinatal predictors of clinical instability at birth in late-preterm and term infants

To identify characteristics associated with delivery room clinical instability in at-risk infants. Prospective cohort study. Two perinatal centres in Melbourne, Australia. Infants born at ≥ 35⁺⁰ weeks' gestation with a first-line paediatric doctor requested to attend. Clinical instability defined as any one of heart rate < 100 beats per minute for ≥ 20 s in the first 10 min after birth, maximum fraction of inspired oxygen of ≥ 0.70 in the first 10 min after birth, 5-min Apgar score of < 7, intubated in the delivery room or admitted to the neonatal unit for respiratory support. Four hundred and seventy-three infants were included. The median (IQR) gestational age at birth was 39⁺⁴ (38⁺⁴-40⁺⁴) weeks. Eighty (17%) infants met the criteria for clinical instability. Independent risk factors for clinical instability were labour without oxytocin administration, presence of a medical pregnancy complication, difficult extraction at birth and unplanned caesarean section in labour. Decision tree analysis determined that infants at highest risk were those whose mothers did not receive oxytocin during labour (25% risk). Infants at lowest risk were those whose mothers received oxytocin during labour and did not have a medical pregnancy complication (7% risk).

CONCLUSIONS

We identified characteristics associated with clinical instability that may be useful in alerting less experienced clinicians to call for senior assistance early. The decision trees provide intuitive visual aids but require prospective validation.

WHAT IS KNOWN

• First-line clinicians attending at-risk births may need to call senior colleagues for assistance depending on the infant's condition. • Delays in effectively supporting a compromised infant at birth is an important cause of neonatal morbidity and infant-mother separation.

WHAT IS NEW

• This study identifies risk factors for delivery room clinical instability in at-risk infants born at ≥ 35⁺⁰ weeks' gestation. • The decision trees presented provide intuitive visual tools to aid in determining the need for senior paediatric presence.

The Respiratory Management of the Extreme Preterm in the Delivery Room

The fetal-to-neonatal transition poses an extraordinary challenge for extremely low birth weight (ELBW) infants, and postnatal stabilization in the delivery room (DR) remains challenging. The initiation of air respiration and the establishment of a functional residual capacity are essential and often require ventilatory support and oxygen supplementation. In recent years, there has been a tendency towards the soft-landing strategy and, subsequently, non-invasive positive pressure ventilation has been generally recommended by international guidelines as the first option for stabilizing ELBW in the delivery room. On the other hand, supplementation with oxygen is another cornerstone of the postnatal stabilization of ELBW infants. To date, the conundrum concerning the optimal initial inspired fraction of oxygen, target saturations in the first golden minutes, and oxygen titration to achieve desired stability saturation and heart rate values has not yet been solved. Moreover, the retardation of cord clamping together with the initiation of ventilation with the patent cord (physiologic-based cord clamping) have added additional complexity to this puzzle. In the present review, we critically address these relevant topics related to fetal-to-neonatal transitional respiratory physiology, ventilatory stabilization, and oxygenation of ELBW infants in the delivery room based on current evidence and the most recent guidelines for newborn stabilization.

Effect of Breathing Support in Very Preterm Infants Not Breathing During Deferred Cord Clamping: A Randomized Controlled Trial (The ABC Study)

OBJECTIVE

To determine if providing respiratory support to very preterm infants who fail to breathe regularly during deferred cord clamping (DCC) decreased red cell transfusion.

STUDY DESIGN

Infants less than 31 weeks of gestation undergoing DCC who were apneic or not breathing regularly at 15 seconds underwent stratified randomization. Pale, limp, and nonresponsive infants were excluded. The standard group received gentle stimulation in a neutral position for 50 seconds; the intervention group received intermittent positive pressure ventilation via face mask and T piece from 20 to 50 seconds of age with a fractional inspired oxygen of 0.3. The primary outcome was the proportion transfused, with a secondary composite outcome of death, severe intraventricular hemorrhage, or chronic lung disease.

RESULTS

Of 311 assessed infants, 113 met the inclusion criteria and were studied; 57 received the intervention and 56 standard treatment. Patient characteristics were similar. Overall, 105 infants (93%) received the intended 50 seconds DCC (54 in the intervention group and 51 in the standard group). Rates of transfusion were similar (28% vs 30% in the intervention vs control groups), as were rates of the composite outcome (46% vs 38% in the intervention vs the control arms; P = .45).

CONCLUSIONS

Providing breathing support during 50 seconds of DCC in this single-center cohort seemed to be safe and feasible, but did not decrease the transfusion rates or improve outcomes.

TRIAL REGISTRATION

http://www.anzctr.org.au/ACTRN12615001026516.aspx.

Does physiological-based cord clamping improve cerebral tissue oxygenation and perfusion in healthy term neonates? - A randomized controlled trial

OBJECTIVES

To evaluate cerebral tissue oxygenation index (cTOI) during neonatal transition in a group of healthy full-term neonates receiving either a physiological-based approach of deferred cord clamping (CC) after the onset of stable regular breathing (PBCC group) or a standard approach of time-based CC < 1 min (control group). Secondary aim was to evaluate changes in cerebral blood volume (ΔCBV), peripheral arterial oxygen saturation (SpO2) and heart rate (HR) in those neonates.

MATERIALS AND METHODS

We conducted a randomized controlled trial (clinicaltrials.gov: NCT02763436) including vaginally delivered healthy full-term neonates. Continuous measurements of cTOI and ΔCBV using near-infrared spectroscopy, and of SpO2 and HR using pulse oximetry were performed within the first 15 min after birth. Data of each minute of the PBCC group were compared to those of the control group.

RESULTS

A total of 71 full-term neonates (PBCC: n = 35, control: n = 36) with a mean (SD) gestational age of 40.0 (1.0) weeks and a birth weight of 3,479 (424) grams were included. Median (IQR) time of CC was 275 (197-345) seconds and 58 (35-86) seconds in the PBCC and control group, respectively (p < 0.001). There were no significant differences between the two groups regarding cTOI (p = 0.319), ΔCBV (p = 0.814), SpO2 (p = 0.322) and HR (p = 0.878) during the first 15 min after birth.

CONCLUSION

There were no significant differences in the course of cTOI as well as ΔCBV, SpO2 and HR during the first 15 min after birth in a group of healthy full-term neonates, who received either deferred CC after the onset of stable regular breathing or standard CC < 1 min. Thus, deferring CC ≥ 1 min following a physiological-based approach offers no benefits regarding cerebral tissue oxygenation and perfusion after uncomplicated vaginal delivery compared to a time-based CC approach.