Using physiology to guide time to cord clamping

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.

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.

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).

Timing of umbilical cord occlusion, delayed vs early, in preterm babies: A randomized controlled trial (CODE-P Trial)

INTRODUCTION

Our hypothesis was that delayed cord clamping (DCC) (not earlier than 30 s; at 30-60 s) in premature neonates (born between 26.0 and 32.6 weeks of gestation), as compared with the usual early cord clamping (ECC), significantly reduces the need for blood transfusions and incidence of intraventricular haemorrhage (IVH) without an increased rate of maternal postpartum haemorrhage.

MATERIAL AND METHODS

A prospective, open-label, randomized, controlled trial was conducted at Vall d'Hebron Hospital from July 2014 to December 2018. All pregnant women at risk of impending preterm birth (≥26.0-<33.0 weeks of gestation) who were admitted to the obstetrics emergency department were evaluated for eligibility. If they met the eligibility criteria, they were invited to participate in the study and, if they agreed, they signed an informed consent. Patients were randomly assigned to one of two groups: ECC group and DCC group.

RESULTS

Our study included a total of 57 patients: 30 in the ECC group and 27 in the DCC group. Due to a lack of funding and low recruitment rates, the study was discontinued in 2018. Maternal characteristics and obstetric outcomes were similar between both groups. The intention-to-treat analysis did not reveal any differences between groups for neonatal red blood cell transfusions, neonatal IVH or maternal postpartum haemorrhage. There were no differences for secondary outcomes. Similarly, no differences were observed in the as-treated analysis.

CONCLUSION

The primary and secondary outcomes of our study were not achieved. Therefore, more meta-analysis and trials are needed to evaluate the appropriate timing of cord clamping in preterm birth.

Cord management in non-vigorous newborns

Cord management in non-vigorous newborns remains up for debate, as limited studies have validated strategies in this high-risk population. While multiple national and international governing bodies now recommend the routine practice of delayed cord clamping (DCC) in vigorous neonates, these organizations have not reached a consensus on the appropriate approach in non-vigorous neonates.1 Benefits of placental transfusion are greatly needed amongst non-vigorous neonates who are at risk of asphyxiation-associated mortality and morbidities, but the need for immediate resuscitation complicates matters. This chapter discusses the physiological benefits of placental transfusion for non-vigorous neonates and reviews the available literature on different umbilical cord management strategies for this population.

The effect of delayed umbilical cord clamping on the infant's beta-endorphin level, mother-infant attachment and breastfeeding

OBJECTIVES

To examine the effect of delayed umbilical cord clamping on the infant's betaendorphin level, mother-infant attachment and breastfeeding.

STUDY DESIGN

This study had an experimental design with a control group. The study was undertaken between October and December 2017 in a maternity hospital in the east of Turkey. In total, 107 pregnant women [55 in the experimental group (delayed cord clamping) and 52 in the control group (early cord clamping)] participated in the study.

RESULTS

The beta-endorphin level in the umbilical cord was 775.80 ± 229.35 in the experimental group and 547.91 ± 290.01 in the control group, and the difference was significant (t = 4.492, p = 0.000). Similarly, the prolactin level in the umbilical cord was 174.26 ± 47.20 in the experimental group and 119.06 ± 47.74 in the control group, and the difference was significant (t = 6.012, p = 0.000). Mother-infant attachment and breastfeeding success were higher in the experimental group.

CONCLUSIONS

Beta-endorphin and prolactin levels in the umbilical cord, mother-infant attachment and breastfeeding success were higher in the group which underwent delayed cord clamping.

A newborn's "life line" - A review of umbilical cord management strategies

Literature supporting various umbilical management strategies have increased substantially over the past decade. Delayed cord clamping and umbilical cord milking are increasing embraced by obstetricians and neonatologists, and multiple international governing bodies now endorse these practices. This review summarizes the benefits and limitations of the different umbilical cord management strategies for term, near-term, and preterm neonates. Additional studies are underway to elucidate the safety profile of these practices, long term outcomes, and variations within these strategies that could potentially augment the benefits.

Optimal time intervals for vaginal breech births: a case-control study

Background

Breech births are associated with a high rate of hypoxic injury, in part due to cord occlusion during emergence. Maximum time intervals and guidelines oriented toward earlier intervention have been proposed in a Physiological Breech Birth Algorithm. We wished to further test and refine the Algorithm for use in a clinical trial.

Methods

We conducted a retrospective case-control study in a London teaching hospital, including 15 cases and 30 controls, during the period of April 2012 to April 2020. Our sample size was powered to test the hypothesis that exceeding recommended time limits is associated with neonatal admission or death. Data collected from intrapartum care records was analysed using SPSS v26 statistical software. Variables were intervals between the stages of labour and various stages of emergence (presenting part, buttocks, pelvis, arms, head). The chi-square test and odds ratios were used to determine association between exposure to the variables of interest and composite outcome. Multiple logistic regression was used to test the predictive value of delays defined as non-adherence the Algorithm.

Results

Logistic regression modelling using the Algorithm time frames had an 86.8% accuracy, a sensitivity of 66.7% and a specificity of 92.3% for predicting the primary outcome. Delays between umbilicus and head >3 minutes (OR: 9.508 [95% CI: 1.390-65.046] p=0.022) and from buttocks on the perineum to head >7 minutes (OR: 6.682 [95% CI: 0.940-41.990] p=0.058) showed the most effect. Lengths of time until the first intervention were consistently longer among the cases. Delay in intervention was more common among cases than head or arm entrapment.

Conclusion

Emergence taking longer than the limits recommended in the Physiological Breech Birth algorithm may be predictive of adverse outcomes. Some of this delay is potentially avoidable. Improved recognition of the boundaries of normality in vaginal breech births may help improve outcomes.

Cardiopulmonary Resuscitation with an Intact Umbilical Cord

The body of literature supporting different umbilical management strategies has increased over the past decade as the role of cord management in neonatal transition is realized. Multiple international governing bodies endorse delayed cord clamping, and this practice is now widely accepted by obstetricians and neonatologists. Although term and preterm neonates benefit in some ways from delayed cord clamping, additional research on variations in this practice, including resuscitation with an intact cord, aim to find the optimal cord management practice that reduces mortality and major morbidities.

Divergent effects of initial ventilation with delayed cord clamping on systemic and pulmonary arterial flows in the birth transition of preterm lambs

A current view that delayed cord clamping (DCC) results in greater haemodynamic stability at birth than immediate cord clamping (ICC) is based on comparison of DCC vs. ICC followed by an asphyxial (∼2 min) cord clamp-to-ventilation (CC-V) interval. More recent data suggest that relatively minor perinatal differences in heart rate and blood pressure fluctuations exist between DCC and ICC with a non-asphyxial (<45 s) CC-V interval, but it is unknown how ventricular output and central arterial blood flow effects of DCC compare with those of non-asphyxial ICC. Anaesthetized preterm fetal lambs instrumented with flow probes on major central arteries were ventilated for 97 (7) s (mean (SD)) before DCC at birth (n = 10), or underwent ICC 40 (6) s before ventilation (n = 10). Compared to ICC, initial ventilation and DCC was accompanied by (1) redistribution of a similar level of ascending aortic flow away from cephalic arteries and towards the aortic isthmus after ventilation; (2) a lower right ventricular output after cord clamping that was redistributed towards the lungs, thereby maintaining the absolute contribution of this output to a similar increase in pulmonary arterial flow after birth; and (3) a lower descending thoracic aortic flow after birth, related to a more rapid decline in phasic right-to-left ductal flow only partially offset by increased aortic isthmus flow. However, systemic arterial flows were similar between DCC and non-asphyxial ICC within 5 min after birth. These findings suggest that compared to non-asphyxial ICC, initial ventilation with DCC transiently redistributed central arterial flows, resulting in lower perinatal systemic arterial, but not pulmonary arterial, flows. KEY POINTS: A current view that delayed cord clamping (DCC) results in greater haemodynamic stability at birth than immediate cord clamping (ICC) is based on comparison of DCC vs. ICC with an asphyxial (∼2 min) cord clamp-to-ventilation (CC-V) interval. Recent data suggest that relatively minor perinatal differences in heart rate and blood pressure fluctuations exist between DCC and ICC with a non-asphyxial (<45 s) CC-V interval, but how central arterial blood flow effects of DCC compare with those of non-asphyxial ICC is unknown. Anaesthetized preterm fetal lambs instrumented with central arterial flow probes underwent initial ventilation for ∼90 s before DCC at birth, or ICC for ∼40 s before ventilation. Compared to non-asphyxial ICC, initial ventilation with DCC redistributed central blood flows, resulting in lower systemic, but not pulmonary, arterial flows during this period of transition. This flow redistribution was transitory, however, with systemic arterial flows similar between DCC and non-asphyxial ICC within minutes after birth.

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.

Characteristics and physiological basis of falls in ventricular outputs after immediate cord clamping at delivery in preterm fetal lambs

KEY POINTS

Controversy exists about the physiological mechanism(s) underlying decreases in cardiac output after immediate clamping of the umbilical cord at birth. To define these mechanisms, the four major determinants of ventricular output (afterload, preload, heart rate and contractility) were measured concurrently in fetal lambs at 15 s intervals over a 2 min period after cord clamping and before ventilation following delivery. After cord clamping, right (but not left) ventricular output fell by 20% in the initial 30 s, due to increased afterload associated with higher arterial blood pressures, but both outputs then halved over 45 s, due to a falling heart rate and deteriorating ventricular contractility accompanying rapid declines in arterial oxygenation to asphyxial levels. Ventricular outputs subsequently plateaued from 75 to 120 s, associated with rebound rises in ventricular contractility accompanying asphyxia-induced surges in circulating catecholamines. These findings provide a physiological basis for the clinical recommendation that effective ventilation should occur within 60 s after immediate cord clamping.

ABSTRACT

Controversy exists about the physiological mechanism(s) underlying large decreases in cardiac output after immediate clamping of the umbilical cord at birth. To define these mechanisms, anaesthetized preterm fetal lambs (127(1)d, n = 12) were instrumented with flow probes and catheters in major central arteries, and a left ventricular (LV) micromanometer-conductance catheter. Following immediate cord clamping at delivery, haemodynamics, LV and right ventricular (RV) outputs, and LV contractility were measured at 15 s intervals during a 2 min non-ventilatory period, with aortic blood gases and circulating catecholamine (noradrenaline and adrenaline) concentrations measured at 30 s intervals. After cord clamping, (1) RV (but not LV) output fell by 20% in the initial 30 s, due to a reduced stroke volume associated with increased arterial blood pressures, (2) both outputs then halved over the next 45 s, associated with falls in heart rate, arterial blood pressures and ventricular contractility accompanying a rapid decline in arterial oxygenation to asphyxial levels, (3) reduced outputs subsequently plateaued from 75 to 120 s, associated with rebound rises in blood pressures and ventricular contractility accompanying exponential surges in circulating catecholamines. These findings are consistent with a time-dependent decline of ventricular outputs after immediate cord clamping, which comprised (1) an initial, minor fall in RV output related to altered loading conditions, (2) ensuing large decreases in both LV and RV outputs related to the combination of bradycardia and ventricular dysfunction during emergence of an asphyxial state, and (3) subsequent stabilization of reduced LV and RV outputs during ongoing asphyxia, supported by cardiovascular stimulatory effects of marked sympathoadrenal activation.

Effect of maternal oxytocin on umbilical venous and arterial blood flows during physiological-based cord clamping in preterm lambs

BACKGROUND

Delayed umbilical cord clamping (UCC) after birth is thought to cause placental to infant blood transfusion, but the mechanisms are unknown. It has been suggested that uterine contractions force blood out of the placenta and into the infant during delayed cord clamping. We have investigated the effect of uterine contractions, induced by maternal oxytocin administration, on umbilical artery (UA) and venous (UV) blood flows before and after ventilation onset to determine whether uterine contractions cause placental transfusion in preterm lambs.

METHODS AND FINDINGS

At ~128 days of gestation, UA and UV blood flows, pulmonary arterial blood flow (PBF) and carotid arterial (CA) pressures and blood flows were measured in three groups of fetal sheep during delayed UCC; maternal oxytocin following mifepristone, mifepristone alone, and saline controls. Each successive uterine contraction significantly (p<0.05) decreased UV (26.2±6.0 to 14.1±4.5 mL.min-1.kg-1) and UA (41.2±6.3 to 20.7 ± 4.0 mL.min-1.kg-1) flows and increased CA pressure and flow (47.1±3.4 to 52.8±3.5 mmHg and 29.4±2.6 to 37.3±3.4 mL.min-1.kg-1). These flows and pressures were partially restored between contractions, but did not return to pre-oxytocin administration levels. Ventilation onset during DCC increased the effects of uterine contractions on UA and UV flows, with retrograde UA flow (away from the placenta) commonly occurring during diastole.

CONCLUSIONS

We found no evidence that amplification of uterine contractions with oxytocin increase placental transfusion during DCC. Instead they decreased both UA and UV flow and caused a net loss of blood from the lamb. Uterine contractions did, however, have significant cardiovascular effects and reduced systemic and cerebral oxygenation.

The Impact of Umbilical Cord Clamping Time on the Infant Anemia: A Randomized Controlled Trial

Background

Anemia during infancy causes irreversible physical, cognitive, motor, and behavioral development disorders. This study aimed to determine the effect of delaying umbilical cord clamping time on certain parameters regarding anemia during the infancy.

Methods

This randomized controlled trial was conducted at a university hospital in west of Turkey (Dec 2017-Dec 2018). Overall, 110 participants were evaluated for the research, 65 participants were randomized after excluding those who did not meet the inclusion criteria (intervention=32, control=33). Randomly assigned to delayed clamping (1 min after delivery) or early clamping (in 15 sec after delivery), and followed up until 4 months postpartum. 48^th-hour hematocrit, bilirubin values, need for phototherapy and hematocrit, hemoglobin values, diagnosis of anemia at the postnatal fourth month were compared between two groups. The data showing normal distribution were assessed using the parametric tests. The level of statistical significance was determined as P<0.05.

Results

The 48^th-hour hematocrit and bilirubin levels of the intervention group were significantly higher than the control (P<0.01 and P<0.05, respectively). No significant difference regarding the need for phototherapy due to postnatal hyperbilirubinemia was observed between the two groups (P>0.05). Means of the intervention group hematocrit and hemoglobin levels measured during anemia screening performed at the fourth month were found to be higher than those of the infants in the control group (P<0.05 and P<0.05, respectively).

Conclusion

Delaying umbilical cord clamping had a positive impact on the haematological parameters of infants. Clamping the cord at least one minute in birth can be performed to prevent the iron deficit anemia that could be seen during the first years of infants' lives.

Umbilical Cord Management for Newborns <34 Weeks' Gestation: A Meta-analysis

CONTEXT

The International Liaison Committee on Resuscitation prioritized scientific review of umbilical cord management strategies at preterm birth.

OBJECTIVE

To determine the effects of umbilical cord management strategies (including timing of cord clamping and cord milking) in preterm infants <34 weeks' gestation.

DATA SOURCES

Cochrane Central Register of Controlled Trials, Medline, PubMed, Embase, CINAHL, and trial registries were searched through July 2019 for randomized controlled trials assessing timing of cord clamping and/or cord milking.

STUDY SELECTION

Two authors independently assessed trial eligibility, extracted data, appraised risk of bias, and assessed evidence certainty (GRADE).

DATA EXTRACTION

We identified 42 randomized controlled trials (including 5772 infants) investigating 4 different comparisons of cord management interventions.

RESULTS

Compared to early cord clamping, delayed cord clamping (DCC) and intact-cord milking (ICM) may slightly improve survival; however, both are compatible with no effect (DCC: risk ratio: 1.02, 95% confidence interval: 1.00 to 1.04, n = 2988 infants, moderate certainty evidence; ICM: risk ratio: 1.02, 95% confidence interval: 0.98 to 1.06, n = 945 infants, moderate certainty evidence). DCC and ICM both probably improve hematologic measures but may not affect major neonatal morbidities.

LIMITATIONS

For many of the included comparisons and outcomes, certainty of evidence was low. Our subgroup analyses were limited by few researchers reporting subgroup data.

CONCLUSIONS

DCC appears to be associated with some benefit for infants born <34 weeks. Cord milking needs further evidence to determine potential benefits or harms. The ideal cord management strategy for preterm infants is still unknown, but early clamping may be harmful.

Australian maternity healthcare professionals' knowledge, attitudes and practices relevant to cord blood banking, donation and clamp timing: A cross-sectional survey

PROBLEM

Australian health professionals' knowledge and attitudes towards third stage labour options of cord clamp timing, cord blood banking and donation and their practice of informing parents of these options is unknown.

BACKGROUND

Parents have several options for the management of their infant' cord blood during the third stage of labour. Early or deferred cord clamping practices may affect parent choices about physiological transfusion to the neonate and/or cord blood collection for private or public banking or donation.

AIM

To identify health professionals' knowledge and attitudes towards third stage labour options of cord clamp timing, cord blood banking and donation and their practice of informing parents of these options.

METHODS

A total of 129 Australian maternity healthcare professionals responded to the self-administered survey between December 2017 and June 2018.

FINDINGS

Occupational differences were revealed in regard to cord clamp timing, cord blood banking and donation knowledge, attitudes and practices. Midwives were more likely to discuss cord clamp timing with parents and to clamp the cord later than obstetricians. Obstetricians were more knowledgeable of cord blood banking and donation options than midwives. Cord blood banking and donation options were discussed by both groups if parents asked.

DISCUSSION

Identification of gaps in knowledge should guide future maternity health professional education that is inclusive of all third stage labour options to ensure that open discussion and informing parents of options is consistent, contemporary and evidence-based.

CONCLUSION

To make informed decisions, parents need evidence-based information on all third stage labour options.

A Comparison of Strategies for Managing the Umbilical Cord at Birth in Preterm Infants

OBJECTIVE

To evaluate the rates of practice, and the associations between different cord management strategies at birth (delayed cord clamping [DCC], umbilical cord milking [UCM], and early cord clamping [ECC]) and mortality or major morbidity, rates of blood transfusion, and peak serum bilirubin in a large national cohort of very preterm infants.

STUDY DESIGN

We retrospectively studied preterm infants <33 weeks of gestation admitted to the Canadian Neonatal Network between January 2015 and December 2017. Patients who received ECC (<30 seconds), UCM, or DCC (≥30 seconds) were compared. Multiple generalized linear/quantile logistic regression models were used.

RESULTS

Of 12 749 admitted infants, 9729 were included; 4916 (50.5%) received ECC, 394 (4.1%) UCM, and 4419 (45.4%) DCC. After adjustment for potential confounders identified between groups in univariate analyses, the odds of mortality or major morbidity were higher in the ECC group when compared with UCM group (aOR, 1.18; 95% CI, 1.03-1.35). Mortality and intraventricular hemorrhage were associated with ECC as compared with DCC (aOR, 1.6 [95% CI, 1.22-2.1] and aOR, 1.29 [95% CI, 1.19-1.41], respectively). The odds of severe intraventricular hemorrhage were higher with UCM compared with DCC (aOR, 1.38; 95% CI, 1.05-1.81). Rates of blood transfusion were higher with ECC compared with UCM and DCC (aOR, 1.67 [95% CI, 1.31-2.14] and aOR, 1.68 [95% CI, 1.35-2.09], respectively), although peak serum bilirubin levels were not significantly different.

CONCLUSIONS

Both DCC and UCM were associated with better short-term outcomes than ECC; however, the odds of severe intraventricular hemorrhage were higher with UCM compared with DCC.

Identifying women giving birth preterm and care at the time of birth: a prospective audit of births at six hospitals in India, Kenya, Pakistan and Uganda

Background

Globally, 15 million infants are born preterm each year, and 1 million die due to complications of prematurity. Over 60% of preterm births occur in Sub-Saharan Africa and south Asia. Care at birth for premature infants may be critical for survival and long term outcome. We conducted a prospective audit to assess whether women giving birth preterm could be identified, and to describe cord clamping and neonatal care at hospitals in Africa and south Asia.

Methods

This prospective audit of livebirths was conducted at six hospitals in Uganda, Kenya, India and Pakistan. Births were considered preterm if between 28^+ 0 and 33^+ 6 weeks gestation and/or the birthweight was 1.00 to 1.99 kg. A pre-specified audit plan was agreed with each hospital. Livebirths before 28 weeks gestation with birthweight less than 1.0 kg were excluded. Data were collected on estimated and actual gestation and birthweight, cord clamping, and neonatal care.

Results

Of 4149 women who gave birth during the audit, data were available for 3687 (90%). As 107 were multiple births, 3781 livebirths were included, of which 257 (7%) were preterm. Antenatal assessment correctly identified 148 infants as ‘preterm’ and 3429 as ‘term’, giving a positive predictive value of 72% and negative predictive value of 97%. For term births, cord clamping was usually later at the two Ugandan hospitals, median time to clamping 50 and 76 s, compared with 23 at Kenyatta (Kenya), 7 at CMC (India) and 12 at FBH/LNH (Pakistan). At the latter two, timing was similar between term and preterm births, and between vaginal and Caesarean births. For all the hospitals, the cord was clamped quickly at Caesarean births, with Mbale (Uganda) having the highest median time to clamping (15 s ‘term’, 19 ‘preterm’). For preterm infants temperature on admission to the neonatal unit was below 35.5 °C for 50%, and 59 (23%) died before hospital discharge.

Conclusions

Antenatal identification of preterm birth was good. Timing of cord clamping varied between hospitals, although at each there was no difference between ‘term’ and ‘preterm’ births. For premature infants hypothermia was common, and mortality before hospital discharge was high.

Systematic review and network meta-analysis with individual participant data on cord management at preterm birth (iCOMP): study protocol

INTRODUCTION

Timing of cord clamping and other cord management strategies may improve outcomes at preterm birth. However, it is unclear whether benefits apply to all preterm subgroups. Previous and current trials compare various policies, including time-based or physiology-based deferred cord clamping, and cord milking. Individual participant data (IPD) enable exploration of different strategies within subgroups. Network meta-analysis (NMA) enables comparison and ranking of all available interventions using a combination of direct and indirect comparisons.

OBJECTIVES

(1) To evaluate the effectiveness of cord management strategies for preterm infants on neonatal mortality and morbidity overall and for different participant characteristics using IPD meta-analysis. (2) To evaluate and rank the effect of different cord management strategies for preterm births on mortality and other key outcomes using NMA.

METHODS AND ANALYSIS

Systematic searches of Medline, Embase, clinical trial registries, and other sources for all ongoing and completed randomised controlled trials comparing cord management strategies at preterm birth (before 37 weeks' gestation) have been completed up to 13 February 2019, but will be updated regularly to include additional trials. IPD will be sought for all trials; aggregate summary data will be included where IPD are unavailable. First, deferred clamping and cord milking will be compared with immediate clamping in pairwise IPD meta-analyses. The primary outcome will be death prior to hospital discharge. Effect differences will be explored for prespecified participant subgroups. Second, all identified cord management strategies will be compared and ranked in an IPD NMA for the primary outcome and the key secondary outcomes. Treatment effect differences by participant characteristics will be identified. Inconsistency and heterogeneity will be explored.

ETHICS AND DISSEMINATION

Ethics approval for this project has been granted by the University of Sydney Human Research Ethics Committee (2018/886). Results will be relevant to clinicians, guideline developers and policy-makers, and will be disseminated via publications, presentations and media releases.

REGISTRATION NUMBER

Australian New Zealand Clinical Trials Registry (ANZCTR) (ACTRN12619001305112) and International Prospective Register of Systematic Reviews (PROSPERO, CRD42019136640).

Brief asphyxial state following immediate cord clamping accelerates onset of left-to-right shunting across the ductus arteriosus after birth in preterm lambs

Reversal of shunting across the ductus arteriosus from right-to-left to left-to-right is a characteristic feature of the birth transition. Given that immediate cord clamping (ICC) followed by an asphyxial cord clamp-to-ventilation (CC-V) interval may augment left ventricular (LV) output and central blood flows after birth, we tested the hypothesis that an asphyxial CC-V interval accelerates the onset of postnatal left-to-right ductal shunting. High-fidelity central blood flow signals were obtained in anesthetized preterm lambs (gestation 128 ± 2 days) after ICC followed by a nonasphyxial (∼40 s, n = 9) or asphyxial (∼90 s, n = 9) CC-V interval before mechanical ventilation for 30 min after birth. Left-to-right ductal flow segments were related to aortic isthmus and descending aortic flow profiles to quantify sources of ductal shunting. In the nonasphyxial group, phasic left-to-right ductal shunting was initially minor after birth, but then rose progressively to 437 ± 164 ml/min by 15 min (P < 0.001). However, in the asphyxial group, this shunting increased from 24 ± 21 to 199 ± 93 ml/min by 15 s after birth (P < 0.001) and rose further to 471 ± 190 ml/min by 2 min (P < 0.001). This earlier onset of left-to-right ductal shunting was supported by larger contributions (P < 0.001) from direct systolic LV flow and retrograde diastolic discharge from an arterial reservoir/windkessel located in the descending aorta and its major branches, and associated with increased pulmonary arterial blood flow having a larger ductal component. These findings suggest that the duration of the CC-V interval after ICC is an important modulator of left-to-right ductal shunting, LV output and pulmonary perfusion at birth.NEW & NOTEWORTHY This birth transition study in preterm lambs demonstrated that a brief (∼90 s) asphyxial interval between umbilical cord clamping and ventilation onset resulted in earlier and greater left-to-right shunting across the ductus arteriosus after birth. This greater shunting 1) resulted from an increased left ventricular output associated with a higher systolic left-to-right ductal flow and increased retrograde diastolic discharge from a lower body arterial reservoir/windkessel, and 2) was accompanied by greater lung perfusion after birth.

Issues in cardiopulmonary transition at birth

The transition from fetal to newborn life involves a complex series of physiological events that commences with lung aeration, which is thought to involve 3 mechanisms. Two mechanisms occur during labour, Na⁺ reabsorption and fetal postural changes, and one occurs after birth due to pressure gradients generated by inspiration. However, only one of these mechanisms, fetal postural changes, involves the loss of liquid from the respiratory system. Both other mechanisms involve liquid being reabsorbed from the airways into lung tissue. While this stimulates an increase in pulmonary blood flow (PBF), in large quantities this liquid can adversely affect postnatal respiratory function. The increase in PBF (i) facilitates the onset of pulmonary gas exchange and (ii) allows pulmonary venous return to take over the role of providing preload for the left ventricle, a role played by umbilical venous return during fetal life. Thus, aerating the lung and increasing PBF before umbilical cord clamping (known as physiological based cord clamping), can avoid the loss of preload and reduction in cardiac output that normally accompanies immediate cord clamping.

Blunted sympathoadrenal activation accompanies hemodynamic stability after early ventilation and delayed cord clamping at birth in preterm lambs

BACKGROUND

As surges in circulating norepinephrine and epinephrine have chronotropic, pressor, and inotropic effects, we tested the hypothesis that blunted rises in these catecholamines during preterm birth accompanied hemodynamic stability observed after early ventilation and delayed cord clamping (DCC), with findings compared to immediate cord clamping (ICC) and a non-asphyxial cord clamp-to-ventilation interval.

METHODS

Anesthetized preterm fetal lambs were instrumented with arterial micromanometers to obtain pressure and the maximal rate of pressure rise (dP/dt_max) as a surrogate of ventricular contractility and an aortic catheter to obtain blood samples for catecholamine assay. Fetuses were delivered and mechanically ventilated before cord clamping ∼1.5 min later (DCC, n = 9) or subjected to ICC with ventilation started ∼40 s later (n = 8).

RESULTS

Perinatal hemodynamics were stable after DCC, with greater fluctuations evident following birth after ICC (P ≤ 0.05). With DCC, circulating norepinephrine and epinephrine were unchanged after early ventilation but rose following cord clamping (P ≤ 0.01), with concentrations below the threshold for hemodynamic effects. Norepinephrine was higher in the ICC group after cord clamping and immediately after ventilation (P < 0.025), but catecholamine levels were otherwise similar between groups.

CONCLUSION

Hemodynamic stability at birth after DCC is accompanied by sub-threshold rises in circulating norepinephrine and epinephrine and thus blunted sympathoadrenal activation.

Effect of timing of umbilical cord clamping and other strategies to influence placental transfusion at preterm birth on maternal and infant outcomes

BACKGROUND

Infants born preterm (before 37 weeks' gestation) have poorer outcomes than infants at term, particularly if born before 32 weeks. Early cord clamping has been standard practice over many years, and enables quick transfer of the infant to neonatal care. Delayed clamping allows blood flow between the placenta, umbilical cord and baby to continue, and may aid transition. Keeping baby at the mother's side enables neonatal care with the cord intact and this, along with delayed clamping, may improve outcomes. Umbilical cord milking (UCM) is proposed for increasing placental transfusion when immediate care for the preterm baby is needed. This Cochrane Review is a further update of a review first published in 2004 and updated in 2012.

OBJECTIVES

To assess the effects on infants born at less than 37 weeks' gestation, and their mothers of: 1) delayed cord clamping (DCC) compared with early cord clamping (ECC) both with immediate neonatal care after cord clamping; 2) DCC with immediate neonatal care with cord intact compared with ECC with immediate neonatal care after cord clamping; 3) DCC with immediate neonatal care after cord clamping compared with UCM; 4) UCM compared with ECC with immediate neonatal care after cord clamping.

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth Group Trials Register, ClinicalTrials.gov, the WHO International Clinical Trials Registry Platform (ICTRP) (10 November 2017), and reference lists of retrieved studies. We updated the search in November 2018 and added nine new trial reports to the awaiting classification section to be assessed at the next update.

SELECTION CRITERIA

Randomised controlled trials (RCTs) comparing delayed with early clamping of the umbilical cord (with immediate neonatal care after cord clamping or with cord intact) and UCM for births before 37 weeks' gestation. Quasi-RCTs were excluded.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trials for inclusion and risk of bias, extracted data and checked them for accuracy. Random-effects are used in all meta-analyses. Review authors assessed the certainty of the evidence using the GRADE approach.

MAIN RESULTS

This update includes forty-eight studies, involving 5721 babies and their mothers, with data available from 40 studies involving 4884 babies and their mothers. Babies were between 24 and 36+6 weeks' gestation at birth and multiple births were included. The data are mostly from high-income countries. Delayed clamping ranged between 30 to 180 seconds, with most studies delaying for 30 to 60 seconds. Early clamping was less than 30 seconds and often immediate. UCM was mostly before cord clamping but some were milked after cord clamping. We undertook subgroup analysis by gestation and type of intervention, and sensitivity analyses by low risk of selection and attrition bias.All studies were high risk for performance bias and many were unclear for other aspects of risk of bias. Certainty of the evidence using GRADE was mostly low, mainly due to imprecision and unclear risk of bias.Delayed cord clamping (DCC) versus early cord clamping (ECC) both with immediate neonatal care after cord clamping (25 studies, 3100 babies and their mothers)DCC probably reduces the number of babies who die before discharge compared with ECC (average risk ratio (aRR) 0.73, 95% confidence interval (CI) 0.54 to 0.98, 20 studies, 2680 babies (moderate certainty)).No studies reported on 'Death or neurodevelopmental impairment' in the early years'.DCC may make little or no difference to the number of babies with severe intraventricular haemorrhage (IVH grades 3 and 4) (aRR 0.94, 95% CI 0.63 to 1.39, 10 studies, 2058 babies, low certainty) but slightly reduces the number of babies with any grade IVH (aRR 0.83, 95% CI 0.70 to 0.99, 15 studies, 2333 babies, high certainty).DCC has little or no effect on chronic lung disease (CLD) (aRR 1.04, 95% CI 0.94 to 1.14, 6 studies, 1644 babies, high certainty).Due to insufficient data, we were unable to form conclusions regarding periventricular leukomalacia (PVL) (aRR 0.58, 95% CI 0.26 to 1.30, 4 studies, 1544 babies, low certainty) or maternal blood loss of 500 mL or greater (aRR 1.14, 95% CI 0.07 to 17.63, 2 studies, 180 women, very low certainty).We identified no important heterogeneity in subgroup or sensitivity analyses.Delayed cord clamping (DCC) with immediate neonatal care with cord intact versus early cord clamping (ECC) (one study, 276 babies and their mothers)There are insufficient data to be confident in our findings, but DCC with immediate neonatal care with cord intact may reduce the number of babies who die before discharge, although the data are also compatible with a slight increase in mortality, compared with ECC (aRR 0.47, 95% CI 0.20 to 1.11, 1 study, 270 babies, low certainty). DCC may also reduce the number of babies who die or have neurodevelopmental impairment in early years (aRR 0.61, 95% CI 0.39 to 0.96, 1 study, 218 babies, low certainty). There may be little or no difference in: severe IVH; all grades IVH; PVL; CLD; maternal blood loss ≥ 500 mL, assessed as low certainty mainly due to serious imprecision.Delayed cord clamping (DCC) with immediate neonatal care after cord clamping versus umbilical cord milking (UCM) (three studies, 322 babies and their mothers) and UCM versus early cord clamping (ECC) (11 studies, 1183 babies and their mothers)There are insufficient data for reliable conclusions about the comparative effects of UCM compared with delayed or early clamping (mostly low or very low certainty).

AUTHORS' CONCLUSIONS

Delayed, rather than early, cord clamping may reduce the risk of death before discharge for babies born preterm. There is insufficient evidence to show what duration of delay is best, one or several minutes, and therefore the optimum time to clamp the umbilical cord remains unclear. Whilst the current evidence supports not clamping the cord before 30 seconds at preterm births, future trials could compare different lengths of delay. Immediate neonatal care with the cord intact requires further study, and there are insufficient data on UCM.The nine new reports awaiting further classification may alter the conclusions of the review once assessed.

Skin-to-skin contact the first hour after birth, underlying implications and clinical practice

AIM

This paper integrates clinical expertise to earlier research about the behaviours of the healthy, alert, full-term infant placed skin-to-skin with the mother during the first hour after birth following a noninstrumental vaginal birth.

METHOD

This state-of-the-art article forms a link within the knowledge-to-action cycle, integrating clinical observations and practice with evidence-based findings to guide clinicians in their work to implement safe uninterrupted skin-to-skin contact the first hours after birth.

RESULTS

Strong scientific research exists about the importance of skin-to-skin in the first hour after birth. This unique time for both mother and infant, individually and in relation to each other, provides vital advantages to short- and long-term health, regulation and bonding. However, worldwide, clinical practice lags. A deeper understanding of the implications for clinical practice, through review of the scientific research, has been integrated with enhanced understanding of the infant's instinctive behaviour and maternal responses while in skin-to-skin contact.

CONCLUSION

The first hour after birth is a sensitive period for both the infant and the mother. Through an enhanced understanding of the newborn infant's instinctive behaviour, practical, evidence-informed suggestions strive to overcome barriers and facilitate enablers of knowledge translation. This time must be protected by evidence-based routines of staff.

Evaluation of umbilical cord pulsatility after vaginal delivery in singleton pregnancies at term

OBJECTIVES

To define the duration of umbilical cord pulsatility (UCP) after vaginal delivery and to evaluate its possible association with maternal characteristics and obstetric and neonatal variables.

STUDY DESIGN

Prospective observational study on women with a singleton pregnancy at term who had a vaginal delivery and cord clamping at the cessation of pulsations. The collection of UCP duration was performed through a stopwatch and by manual palpation of the umbilical cord. Maternal (age, BMI, parity, antepartum hemoglobin), obstetric (pregnancy characteristics, gestational age at delivery, induction of labor, duration of the first, the second and the third stage of labor, post-partum blood loss, umbilical cord length) and neonatal (birthweight, Apgar score, hematocrit, hemoglobin) variables were then compared between two groups: long-term vs. short-term UCP.

RESULTS

A total of 102 women were identified. The median duration of UCP after birth was 213 s (IQR 120, 420), corresponding to 3 min and 33 s. The long-term UCP group (n = 51) had a significantly longer duration of third stage of labor (median 12 vs. 8 min, p < 0.001) and a significantly higher birthweight (median 3530 g vs. 3250 g, p = 0.005) compared with the short-term UCP group (n = 51). No differences in the other variables were found between groups.

CONCLUSION

For the first time we have reported the duration of UCP after vaginal delivery. An increased duration of UCP is associated with a prolonged duration of third stage of labor and a higher birthweight.

Effects of delayed cord clamping on infants after neonatal period: A systematic review and meta-analysis

BACKGROUND

The majority of current evidences simply showed the short-term benefits of delayed cord clamping, mainly focusing on the first week after birth. Without follow-up data, we can hardly come to the conclusion that delayed cord clamping may do more harm than good.

OBJECTIVE

To evaluate the long-term effects of delayed cord clamping compared with early cord clamping on infants after neonatal period.

DESIGN

Systematic review and meta-analysis of randomized controlled trials (RCTs).

DATA SOURCES

PubMed, EMBASE, and the Cochrane Library were systematically searched from inception date to June 22, 2018 for randomized clinical trials comparing early cord clamping with delayed cord clamping in infants beyond 1 month of age.

REVIEW METHODS

Two reviewers independently assessed trial eligibility and quality and extracted all infants' follow-up data after one month of age, which were divided into two groups for analysis, with follow-up periods of less than 6 months (<6 months) and beyond 6 months (≥6 months) respectively.

RESULTS

A total of twenty RCTs were identified and included in this study. All data of the twenty studies were pooled for final meta-analysis (3733 infants). Among preterm deliveries, delayed cord clamping slightly increased hematocrit (6-10 weeks) and serum ferritin (6-10 weeks). For term infants, delayed cord clamping reduced the incidence of anemia after six months of age (≥6 months), iron deficiency (< 6 months, ≥6 months) and iron deficiency anemia (4-12 months), while increased mean corpuscular volume before six months of age (< 6 months), hemoglobin after six months of age (≥6 months), serum iron (2-4 months), total body iron (4-6 months), serum ferritin (< 6 months, ≥6 months) and transferrin saturation (2-12 months). There were no significant differences between early versus late cord clamping groups for other variables.

CONCLUSION

Delayed cord clamping modestly improved hematological and iron status of both preterm and term infants after neonatal period. This affords cogent evidence on the practice of delayed cord clamping for medical staff, especially for countries and regions suffering from relatively higher prevalence rate of iron deficiency during infancy and childhood.

A new wrinkle: Umbilical cord management (how, when, who)

In the past five years, umbilical cord management in both term and preterm infants has come full circle, going from the vast majority of infants receiving immediate cord clamping to virtually all governing organizations promoting placental transfusion, mainly in the form of delayed cord clamping (DCC). Placental transfusion refers to the transfer of more blood components to the infant during the first few minutes after birth. The different strategies for ensuring placental transfusion to the baby include delayed (deferred) cord clamping, milking of the attached cord before clamping, and milking of the cut cord. In this review, we address the current evidence to date for providing placental transfusion in different circumstances and the methods for implementation. We also highlight the gaps in knowledge and areas for future research.

Umbilical cord milking in preterm neonates requiring resuscitation: A randomized controlled trial

OBJECTIVE

To evaluate the effect of cord milking on short term morbidity and hematologic parameters at 6 weeks in preterm neonates requiring resuscitation.

METHODS

This trial randomized preterm infants requiring resuscitation to milking group and no milking group. Multiple pregnancy, Rh negative mothers, hydrops, cord abnormalities were excluded. The primary outcome was hemoglobin and serum ferritin at 6 weeks of life. Secondary outcomes were common preterm morbidities and mortality.

RESULTS

60 neonates were included in the study. Infants in the milking group had higher hemoglobin (10.07 g/dl vs 8.9 g/dl; p 0.003) and higher serum ferritin level (244.8 ng/ml vs 148.5 ng/ml; p 0.04) compared to no milking group.

CONCLUSIONS

In preterm neonates requiring resuscitation, umbilical cord milking results in higher hemoglobin and ferritin at 6 weeks of life. It can be a used as a placental transfusion strategy in preterm neonates requiring resuscitation with no significant adverse effects.

CLINICAL TRIAL REGISTRATION

Clinical trials registry -India CTRI/2015/01/005436, www.ctri.nic.in.

Peripartum Haemorrhage, Diagnosis and Therapy. Guideline of the DGGG, OEGGG and SGGG (S2k Level, AWMF Registry No. 015/063, March 2016)

Purpose

This is an official interdisciplinary guideline, published and coordinated by the German Society of Gynaecology and Obstetrics (DGGG), the Austrian Society of Gynaecology and Obstetrics (OEGGG) and the Swiss Society of Gynaecology and Obstetrics (SGGG). The guideline was developed for use in German-speaking countries and is backed by the German Society of Anaesthesiology and Intensive Medicine (DGAI), the Society of Thrombosis and Haemostasis Research (GTH) and the German Association of Midwives. The aim is to provide a consensus-based overview of the diagnosis and management of peripartum bleeding obtained from an evaluation of the relevant literature.

Methods

This S2k guideline was developed from the structured consensus of representative members of the various professional associations and professions commissioned by the Guideline Commission of the DGGG.

Recommendations

The guideline encompasses recommendations on definitions, risk stratification, prevention and management.

Italian Recommendations for Placental Transfusion Strategies

At delivery, if the cord is not clamped, blood continues to pass from the placenta to the newborn during the first minutes of life, allowing the transfer of 25-35 ml/kg of placental blood to the newborn, depending on gestational age, the timing of cord clamping, the position of the infant at birth, the onset of respiration, and administration of uterotonics to the mother. However, deriving benefits from delayed cord clamping (DCC) are not merely related to placental-to-fetal blood transfusion; establishing spontaneous ventilation before cutting the cord improves venous return to the right heart and pulmonary blood flow, protecting the newborn from the transient low cardiac output, and systemic arterial pressure fluctuations. Recent meta-analyses showed that delayed cord clamping reduces mortality and red blood cell transfusions in preterm newborns and increases iron stores in term newborns. Various authors suggested umbilical cord milking (UCM) as a safe alternative when delayed cord clamping is not feasible. Many scientific societies recommend waiting 30-60 s before clamping the cord for both term and preterm newborns not requiring resuscitation. To improve the uptake of placental transfusion strategies, in 2016 an Italian Task Force for the Management of Umbilical Cord Clamping drafted national recommendations for the management of cord clamping in term and preterm deliveries. The task force performed a detailed review of the literature using the GRADE methodological approach. The document analyzed all clinical scenarios that operators could deal with in the delivery room, including cord blood gas analysis during delayed cord clamping and time to cord clamping in the case of umbilical cord blood banking. The panel intended to promote a more physiological and individualized approach to cord clamping, specifically for the most preterm newborn. A feasible option to implement delayed cord clamping in very preterm deliveries is to move the neonatologist to the mother's bedside to assess the newborn's clinical condition at birth. This option could safely guarantee the first steps of stabilization before clamping the cord and allow DCC in the first 30 s of life, without delaying resuscitation. Contra-indications to placental transfusion strategies are clinical situations that may endanger mother 's health and those that may delay immediate newborn's resuscitation when required.

Delayed vs early umbilical cord clamping for preterm infants: a systematic review and meta-analysis

BACKGROUND

The effects of delayed cord clamping of the umbilical cord in preterm infants are unclear.

OBJECTIVE

We sought to compare the effects of delayed vs early cord clamping on hospital mortality (primary outcome) and morbidity in preterm infants using Cochrane Collaboration neonatal review group methodology.

STUDY DESIGN

We searched MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials, and Chinese articles, cross-referencing citations, expert informants, and trial registries to July 31, 2017, for randomized controlled trials of delayed (≥30 seconds) vs early (<30 seconds) clamping in infants born <37 weeks' gestation. Before searching the literature, we specified that trials estimated to have cord milking in >20% of infants in any arm would be ineligible. Two reviewers independently selected studies, assessed bias, and extracted data. Relative risk (ie, risk ratio), risk difference, and mean difference with 95% confidence intervals were assessed by fixed effects models, heterogeneity by I² statistics, and the quality of evidence by Grading of Recommendations, Assessment, Development, and Evaluations.

RESULTS

Eighteen randomized controlled trials compared delayed vs early clamping in 2834 infants. Most infants allocated to have delayed clamping were assigned a delay of ≥60 seconds. Delayed clamping reduced hospital mortality (risk ratio, 0.68; 95% confidence interval, 0.52-0.90; risk difference, -0.03; 95% confidence interval, -0.05 to -0.01; P = .005; number needed to benefit, 33; 95% confidence interval, 20-100; Grading of Recommendations, Assessment, Development, and Evaluations = high, with I² = 0 indicating no heterogeneity). In 3 trials in 996 infants ≤28 weeks' gestation, delayed clamping reduced hospital mortality (risk ratio, 0.70; 95% confidence interval, 0.51-0.95; risk difference, -0.05; 95% confidence interval, -0.09 to -0.01; P = .02, number needed to benefit, 20; 95% confidence interval, 11-100; I² = 0). In subgroup analyses, delayed clamping reduced the incidence of low Apgar score at 1 minute, but not at 5 minutes, and did not reduce the incidence of intubation for resuscitation, admission temperature, mechanical ventilation, intraventricular hemorrhage, brain injury, chronic lung disease, patent ductus arteriosus, necrotizing enterocolitis, late onset sepsis or retinopathy of prematurity. Delayed clamping increased peak hematocrit by 2.73 percentage points (95% confidence interval, 1.94-3.52; P < .00001) and reduced the proportion of infants having blood transfusion by 10% (95% confidence interval, 6-13%; P < .00001). Potential harms of delayed clamping included polycythemia and hyperbilirubinemia.

CONCLUSION

This systematic review provides high-quality evidence that delayed clamping reduced hospital mortality, which supports current guidelines recommending delayed clamping in preterm infants. This review does not evaluate cord milking, which may also be of benefit. Analyses of individual patient data in these and other randomized controlled trials will be critically important in reliably evaluating important secondary outcomes.

Management and investigation of neonatal encephalopathy: 2017 update

This review discusses an approach to determining the cause of neonatal encephalopathy, as well as current evidence on resuscitation and subsequent management of hypoxic-ischaemic encephalopathy (HIE). Encephalopathy in neonates can be due to varied aetiologies in addition to hypoxic-ischaemia. A combination of careful history, examination and the judicious use of investigations can help determine the cause. Over the last 7 years, infants with moderate to severe HIE have benefited from the introduction of routine therapeutic hypothermia; the number needed to treat for an additional beneficial outcome is 7 (95% CI 5 to 10). More recent research has focused on optimal resuscitation practices for babies with cardiorespiratory depression, such as delayed cord clamping after establishment of ventilation and resuscitation in air. Around a quarter of infants with asystole at 10 min after birth who are subsequently cooled have normal outcomes, suggesting that individualised decision making on stopping resuscitation is needed, based on access to intensive treatment unit and early cooling. The full benefit of cooling appears to have been exploited in our current treatment protocols of 72 hours at 33.5°C; deeper and longer cooling showed adverse outcome. The challenge over the next 5-10 years will be to assess which adjunct therapies are safe and optimise hypothermic brain protection in phase I and phase II trials. Optimal care may require tailoring treatments according to gender, genetic risk, injury severity and inflammatory status.

Towards evidence-based resuscitation of the newborn infant

Effective resuscitation of the newborn infant has the potential to save many lives around the world and reduce disabilities in children who survive peripartum asphyxia. In this Series paper, we highlight some of the important advances in the understanding of how best to resuscitate newborn infants, which includes monitoring techniques to guide resuscitative efforts, increasing awareness of the adverse effects of hyperoxia, delayed umbilical cord clamping, the avoidance of routine endotracheal intubation for extremely preterm infants, and therapeutic hypothermia for hypoxic-ischaemic encephalopathy. Despite the challenges of performing high-quality clinical research in the delivery room, researchers continue to refine and advance our knowledge of effective resuscitation of newborn infants through scientific experiments and clinical trials.

Fetal Physiology and the Transition to Extrauterine Life

The physiology of the fetus is fundamentally different from the neonate, with both structural and functional distinctions. The fetus is well-adapted to the relatively hypoxemic intrauterine environment. The transition from intrauterine to extrauterine life requires rapid, complex, and well-orchestrated steps to ensure neonatal survival. This article explains the intrauterine physiology that allows the fetus to survive and then reviews the physiologic changes that occur during the transition to extrauterine life. Asphyxia fundamentally alters the physiology of transition and necessitates a thoughtful approach in the management of affected neonates.

Retrograde lower body arterial reservoir discharge underlies rapid reversal of ductus arteriosus shunting after early cord clamping at birth in preterm lambs

Arterial reservoir (“windkessel”) function, whereby a part of left ventricular (LV) output is stored in elastic arteries during systole and discharged in diastole, is a well-established physiological phenomenon. However, its role in rapid reversal (to left-to-right) and a systolic-to-diastolic shift of shunting across the ductus arteriosus after birth is unknown. To address this question, ductal and aortic isthmus flows were measured with high-fidelity transit-time probes in six anesthetized preterm fetal lambs before and after cord clamping and subsequent early mechanical ventilation and for 30 min postbirth. Descending aortic flow was calculated as the sum of isthmus and ductal flows. Left-to-right ductal flow profiles were related to those of the isthmus and descending aorta, with upper body arterial reservoir discharge indicated by forward diastolic isthmus flow, and retrograde lower body arterial reservoir discharge by negative diastolic descending aortic flow. Left-to-right ductal shunting appeared immediately after cord clamping ( P < 0.001), due entirely to newly emergent retrograde lower body reservoir discharge, and rose with ventilation via increased lower body reservoir discharge ( P < 0.005), supplemented by upper body reservoir discharge after 45 s ( P < 0.025) and LV systolic flow after 3 min ( P = 0.025). The contribution of lower body reservoir discharge to left-to-right ductal shunting fell to 55 ± 8% at ≥15 min ( P < 0.001) but remained higher ( P < 0.002) than LV systolic flow (33 ± 8%) or upper body reservoir discharge (12 ± 5%). These results suggest that retrograde lower body arterial reservoir discharge plays a key role in rapid reversal and a systolic-to-diastolic shift of ductal shunting after cord clamping and early ventilation at birth.

Delayed Umbilical Cord Clamping in the 21st Century: Indications for Practice

BACKGROUND

Health care providers have debated the timing of umbilical cord clamping since the days of Aristotle. Delayed cord clamping was the mainstay of practice until about the 1950s when it was changed to immediate clamping on the basis of a series of blood volume studies combined with the introduction of active management of the third stage of labor. However, in recent years, several systematic reviews advise that delayed cord clamping should be used in all births for at least 30 to 60 seconds.

PURPOSE

The purpose of this article is to discuss the physiology of umbilical cord clamping, the potential benefits and adverse effects of delayed cord clamping, and how this affects the advanced practice nurse.

SEARCH STRATEGY

A search of PubMed, Cochrane Reviews, and Clinical Key was used to find relevant research on the topic of umbilical cord clamping.

RESULTS

Potential benefits of delayed cord clamping include decreased frequency of iron-deficiency anemia in the first year of life with improved neurodevelopmental outcomes in term infants, reduced need for blood transfusions, possible autologous transfusion of stem cells, and a decreased incidence of intraventricular hemorrhage. Apprehension exists regarding the feasibility of the practice as well as the potential hindrance of immediate resuscitation.

IMPLICATIONS FOR PRACTICE

There is a need to begin to look for populations for which delayed cord clamping can be implemented.

IMPLICATIONS FOR FUTURE RESEARCH

Recommendations are inconsistent on the patient population and timing; therefore, further studies are needed to understand the multiple variables that affect timing of umbilical cord clamping.