Delayed versus Immediate Cord Clamping in Preterm Infants

Two-Year Outcomes of Umbilical Cord Milking in Nonvigorous Infants: A Secondary Analysis of the MINVI Randomized Clinical Trial

Importance

Compared with early cord clamping (ECC), umbilical cord milking (UCM) reduces delivery room cardiorespiratory support, hypoxic-ischemic encephalopathy, and therapeutic hypothermia in nonvigorous near-term and full-term infants. However, UCM postdischarge outcomes are not known.

Objective

To determine the 2-year outcomes of children randomized to UCM or ECC at birth in the Milking in Nonvigorous Infants (MINVI) trial.

Design, Setting, and Participants

A secondary analysis to evaluate longer-term outcomes of a cluster-randomized crossover trial was conducted from January 9, 2021, to September 25, 2023. The primary trial took place in 10 medical centers in the US, Canada, and Poland from January 5, 2019, to June 1, 2021, and hypothesized that UCM would reduce admission to the neonatal intensive care unit compared with ECC; follow-up concluded September 26, 2023. The population included near-term and full-term infants aged 35 to 42 weeks' gestation at birth who were nonvigorous; families provided consent to complete developmental screening questionnaires through age 2 years.

Intervention

UCM and ECC.

Main Outcomes and Measures

Ages and Stages Questionnaire, 3rd Edition (ASQ-3) and Modified Checklist for Autism in Toddlers, Revised/Follow-Up (M-CHAT-R/F) questionnaires at ages 22 to 26 months. Intention-to-treat analysis and per-protocol analyses were used.

Results

Among 1730 newborns from the primary trial, long-term outcomes were evaluated in 971 children (81%) who had ASQ-3 scores available at 2 years or died before age 2 years and 927 children (77%) who had M-CHAT-R/F scores or died before age 2 years. Maternal and neonatal characteristics by treatment group were similar, with median birth gestational age of 39 (IQR, 38-40) weeks in both groups; 224 infants (45%) in the UCM group and 201 (43%) in the ECC group were female. The median ASQ-3 total scores were similar (UCM: 255 [IQR, 225-280] vs ECC: 255 [IQR, 230-280]; P = .87), with no significant differences in the ASQ-3 subdomains. Medium- to high-risk M-CHAT-R/F scores were also similar (UCM, 9% [45 of 486] vs ECC, 8% [37 of 441]; P = .86).

Conclusions and Relevance

In this secondary analysis of a randomized clinical trial among late near-term and full-term infants who were nonvigorous at birth, ASQ-3 scores at age 2 years were not significantly different between the UCM and ECC groups. Combined with previously reported important short-term benefits, this follow-up study suggests UCM is a feasible, no-cost intervention without longer-term neurodevelopmental risks of cord milking in nonvigorous near-term and term newborns.

Trial Registration

ClinicalTrials.gov Identifier: NCT03631940.

A randomised controlled trial comparing umbilical cord milking to delayed cord clamping at birth in preterm infants 28-36 weeks gestational age

Delayed cord clamping (DCC) is an established practice in perinatology with multiple benefits. However, in instances where the implementation of DCC is not viable, it needs alternatives, especially during caesarean deliveries. A non-inferiority randomized, non-blinded, trial was conducted at a tertiary care referral unit in South India among the preterm newborns (28-36 weeks) randomized to DCC as opposed to intact-umbilical cord milking (UCM). The primary objective was to compare the mean haemoglobin values between the two groups, and the secondary outcome was to compare death and/or major IVH (> Grade II). Of the 132 eligible newborn infants, 99 were randomized to two study groups. Of the 59 and 40 randomised to UCM and DCC, 54 and 36 received the allocated intervention respectively. Preterm infants who underwent UCM had significantly higher haemoglobin (19.97 ± 1.44) as compared to DCC group (18.62 ± 0.98) p-0.0001. The rates of mortality and/or major IVH were comparable between the two groups.

CONCLUSION

UCM may be a feasible alternative to DCC especially in settings where the latter is not achievable, without increasing the risk of adverse effects to the preterm infants, this finding needing further confirmation with larger sample.

TRIAL REGISTRATION

CTRI (Clinical Trial Registry-India) registration number: CTRI/2020/04/024566 (registered prospectively on 13/04/2020).

WHAT IS KNOWN

• Delayed cord clamping (DCC) is recommended as a standard of care for all the stable term and preterm newborn babies at birth.

WHAT IS NEW

• Intact umbilical cord milking may be a reasonable choice of cord management when DCC is unsuccessful, without increasing adverse effects for the new born.

A Bayesian Reanalysis of the Overall and Sex-Disaggregated Results of the Neonatal Oxygenation Prospective Meta-Analysis (NeOProM)

Data from the Neonatal Oxygenation Prospective Meta-analysis (NeOProM) indicate that targeting a higher (91-95%) versus lower (85-89%) pulse oximeter saturation (SpO2) range may reduce mortality and necrotizing enterocolitis (NEC) and increase retinopathy of prematurity (ROP). Aiming to re-evaluate the strength of this evidence, we conducted a Bayesian reanalysis of the NeOProM data. We used Bayes factors (BFs) to evaluate the likelihood of the data under the combination of models assuming the presence vs. absence of effect, heterogeneity, and moderation by sex. The Bayesian reanalysis showed moderate evidence in favor of no differences between SpO2 targets (BF10 = 0.30) in death or major disability, but moderate evidence (BF10 = 3.60) in favor of a lower mortality in the higher SpO2 group. Evidence in favor of differences was observed for bronchopulmonary dysplasia (BPD) (BF10 = 14.44, lower rate with lower SpO2), severe NEC (BF10 = 9.94), and treated ROP (BF10 = 3.36). The only outcome with moderate evidence in favor of sex differences was BPD. This reanalysis of the NeOProM trials confirmed that exposure to a lower versus higher SpO2 range is associated with a higher mortality and risk of NEC, but a lower risk of ROP and BPD. The Bayesian approach can help in assessing the strength of evidence supporting clinical decisions.

Umbilical cord milking and delayed cord clamping for the prevention of neonatal hypoglycaemia: a systematic review and meta-analysis

BACKGROUND

Placental management strategies such as umbilical cord milking and delayed cord clamping may provide a range of benefits for the newborn. The aim of this review was to assess the effectiveness of umbilical cord milking and delayed cord clamping for the prevention of neonatal hypoglycaemia.

METHODS

Three databases and five clinical trial registries were systematically reviewed to identify randomised controlled trials comparing umbilical cord milking or delayed cord clamping with control in term and preterm infants. The primary outcome was neonatal hypoglycaemia (study defined). Two independent reviewers conducted screening, data extraction and quality assessment. Quality of the included studies was assessed using the Cochrane Risk of Bias tool (RoB-2). Certainty of evidence was assessed using the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) approach. Meta-analysis using a random effect model was done using Review Manager 5.4. The review was registered prospectively on PROSPERO (CRD42022356553).

RESULTS

Data from 71 studies and 14 268 infants were included in this review; 22 (2 537 infants) compared umbilical cord milking with control, and 50 studies (11 731 infants) compared delayed with early cord clamping. For umbilical cord milking there were no data on neonatal hypoglycaemia, and no differences between groups for any of the secondary outcomes. We found no evidence that delayed cord clamping reduced the incidence of hypoglycaemia (6 studies, 444 infants, RR = 0.87, CI: 0.58 to 1.30, p = 0.49, I2 = 0%). Delayed cord clamping was associated with a 27% reduction in neonatal mortality (15 studies, 3 041 infants, RR = 0.73, CI: 0.55 to 0.98, p = 0.03, I2 = 0%). We found no evidence for the effect of delayed cord clamping for any of the other outcomes. The certainty of evidence was low for all outcomes.

CONCLUSION

We found no data for the effectiveness of umbilical cord milking on neonatal hypoglycaemia, and no evidence that delayed cord clamping reduced the incidence of hypoglycaemia, but the certainty of the evidence was low.

Quality improvement efforts directed at optimal umbilical cord management in delivery room

Delayed or deferred cord clamping (DCC) and umbilical cord milking (UCM) benefit all infants by optimizing fetal-neonatal transition and placental transfusion. Even though DCC is recommended by almost all maternal and neonatal organizations, it has not been universally implemented. There is considerable variation in umbilical cord management practices across institutions. In this article, we provide examples of successful quality improvement (QI) initiatives to implement optimal cord management in the delivery room. We discuss a number of key elements that should be considering among those undertaking QI efforts to implement DCC and UCM including, multidisciplinary team collaboration, development of theory for change, mapping of the current and ideal process and workflow for cord management, and creation of a unit-specific evidence-based protocol for cord management. We also examine important strategies for implementation and provide suggestions for developing a system for measurement and benchmarking.

[Interpretation of 2023 American Heart Association and American Academy of Pediatrics focused update on neonatal resuscitation guidelines]

In November 2023, the American Heart Association and the American Academy of Pediatrics jointly released key updates to the neonatal resuscitation guidelines based on new clinical evidence. This update serves as an important supplement to the "Neonatal resuscitation: 2020 American Heart Association guidelines for cardiopulmonary resuscitation and emergency cardiovascular care". The aim of this paper is to outline the key updates and provide guidance on umbilical cord management and the selection of positive pressure ventilation equipment and its additional interfaces in neonatal resuscitation.

2023 American Heart Association and American Academy of Pediatrics Focused Update on Neonatal Resuscitation: An Update to the American Heart Association Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care

This 2023 focused update to the neonatal resuscitation guidelines is based on 4 systematic reviews recently completed under the direction of the International Liaison Committee on Resuscitation Neonatal Life Support Task Force. Systematic reviewers and content experts from this task force performed comprehensive reviews of the scientific literature on umbilical cord management in preterm, late preterm, and term newborn infants, and the optimal devices and interfaces used for administering positive-pressure ventilation during resuscitation of newborn infants. These recommendations provide new guidance on the use of intact umbilical cord milking, device selection for administering positive-pressure ventilation, and an additional primary interface for administering positive-pressure ventilation.

Effect of different timings of umbilical cord clamping on the level of CD34+ cells in full-term neonates

Despite the fact that delayed cord clamping (DCC) is recommended by many international organizations, early cord clamping is still widely practiced worldwide. The overarching goal of the DCC practice is to maximize neonatal benefits as achieving higher hemoglobin levels and decreasing the incidence of anemia as well as avoiding the adverse consequences. The current study was conducted to identify the effect of of DCC on the number of CD34+ stem cells in cord blood of full term neonates after two different timings (30 and 60 s after birth). One hundred and three full-term (FT) newborn babies (gestational age 37-40 weeks) delivered by elective cesarean section were randomly assigned into 2 groups: Group 1: babies were subjected to DCC 30 s after birth (50 newborns). Group 2: babies were subjected to DCC 60 s after birth (53 newborns). Neonates in group 2 had significantly higher levels of hemoglobin, hematocrit, total nucleated cells and CD34+ cells compared to those in group 1. The practice of DCC 60 s after birth achieved better CD34+ stem cells transfer in FT neonates than clamping the cord after 30 s.

Deferred cord clamping, cord milking, and immediate cord clamping at preterm birth: a systematic review and individual participant data meta-analysis

BACKGROUND

Umbilical cord clamping strategies at preterm birth have the potential to affect important health outcomes. The aim of this study was to compare the effectiveness of deferred cord clamping, umbilical cord milking, and immediate cord clamping in reducing neonatal mortality and morbidity at preterm birth.

METHODS

We conducted a systematic review and individual participant data meta-analysis. We searched medical databases and trial registries (from database inception until Feb 24, 2022; updated June 6, 2023) for randomised controlled trials comparing deferred (also known as delayed) cord clamping, cord milking, and immediate cord clamping for preterm births (<37 weeks' gestation). Quasi-randomised or cluster-randomised trials were excluded. Authors of eligible studies were invited to join the iCOMP collaboration and share individual participant data. All data were checked, harmonised, re-coded, and assessed for risk of bias following prespecified criteria. The primary outcome was death before hospital discharge. We performed intention-to-treat one-stage individual participant data meta-analyses accounting for heterogeneity to examine treatment effects overall and in prespecified subgroup analyses. Certainty of evidence was assessed with Grading of Recommendations Assessment, Development, and Evaluation. This study is registered with PROSPERO, CRD42019136640.

FINDINGS

We identified 2369 records, of which 48 randomised trials provided individual participant data and were eligible for our primary analysis. We included individual participant data on 6367 infants (3303 [55%] male, 2667 [45%] female, two intersex, and 395 missing data). Deferred cord clamping, compared with immediate cord clamping, reduced death before discharge (odds ratio [OR] 0·68 [95% CI 0·51-0·91], high-certainty evidence, 20 studies, n=3260, 232 deaths). For umbilical cord milking compared with immediate cord clamping, no clear evidence was found of a difference in death before discharge (OR 0·73 [0·44-1·20], low certainty, 18 studies, n=1561, 74 deaths). Similarly, for umbilical cord milking compared with deferred cord clamping, no clear evidence was found of a difference in death before discharge (0·95 [0·59-1·53], low certainty, 12 studies, n=1303, 93 deaths). We found no evidence of subgroup differences for the primary outcome, including by gestational age, type of delivery, multiple birth, study year, and perinatal mortality.

INTERPRETATION

This study provides high-certainty evidence that deferred cord clamping, compared with immediate cord clamping, reduces death before discharge in preterm infants. This effect appears to be consistent across several participant-level and trial-level subgroups. These results will inform international treatment recommendations.

FUNDING

Australian National Health and Medical Research Council.

Short, medium, and long deferral of umbilical cord clamping compared with umbilical cord milking and immediate clamping at preterm birth: a systematic review and network meta-analysis with individual participant data

BACKGROUND

Deferred (also known as delayed) cord clamping can improve survival of infants born preterm (before 37 weeks of gestation), but the optimal duration of deferral remains unclear. We conducted a systematic review and individual participant data network meta-analysis with the aim of comparing the effectiveness of umbilical cord clamping strategies with different timings of clamping or with cord milking for preterm infants.

METHODS

We searched medical databases and trial registries from inception until Feb 24, 2022 (updated June 6, 2023) for randomised controlled trials comparing cord clamping strategies for preterm infants. Individual participant data were harmonised and assessed for risk of bias and quality. Interventions were grouped into immediate clamping, short deferral (≥15 s to <45 s), medium deferral (≥45 s to <120 s), long deferral (≥120 s), and intact cord milking. The primary outcome was death before hospital discharge. We calculated one-stage, intention-to-treat Bayesian random-effects individual participant data network meta-analysis. This study was registered with PROSPERO, CRD42019136640.

FINDINGS

We included individual participant data from 47 trials with 6094 participants. Of all interventions, long deferral reduced death before discharge the most (compared with immediate clamping; odds ratio 0·31 [95% credibility interval] 0·11-0·80; moderate certainty). The risk of bias was low for 10 (33%) of 30 trials, 14 (47%) had some concerns, and 6 (20%) were rated as having a high risk of bias. Heterogeneity was low, with no indication of inconsistency.

INTERPRETATION

This study found that long deferral of clamping leads to reduced odds of death before discharge in preterm infants. In infants assessed as requiring immediate resuscitation, this finding might only be generalisable if there are provisions for such care with the cord intact. These results are based on thoroughly cleaned and checked individual participant data and can inform future guidelines and practice.

FUNDING

Australian National Health and Medical Research Council.

Delayed versus immediate cord clamping in dichorionic twins <32 weeks: a retrospective study

OBJECTIVES

Strong evidence imply that delayed cord clamping (DCC) provides significant benefits for singleton neonates. However, there is little information about the safety or efficacy of DCC in twins to recommend for or against DCC in twins in guidelines. We aimed to determine the effect of DCC on dichorionic twins born at <32 weeks of gestation.

STUDY DESIGN

This is a retrospective cohort study comparing the neonatal and maternal outcomes of immediate cord clamping (ICC) [<15 second (s)] versus DCC (at 60 s). Generalized estimating equations models were performed accounting for twin correlation.

RESULTS

A total of 82 pairs of twins (DCC: 41; ICC: 41) were included in analysis. The primary outcome of death before discharge occurred in 3.66% of twins in the DCC group and 7.32% in the ICC group, without a significant difference between the groups. Compared to ICC group, DCC was associated with increased hemoglobin levels [β1 coefficient 6.51; 95% confidence interval (CI) 0.69-12.32. β2 coefficient 5.80; 95% CI 0.07-11.54] at 12-24 h of life. There were no significant differences between the groups in neonatal death, neonatal major morbidities and maternal bleeding complications, although DCC was associated with higher estimated maternal blood loss in the cesarean section group (p = .005).

CONCLUSIONS

DCC for 60 s in dichorionic twins born at <32 weeks of gestation was associated with increased neonatal hemoglobin levels, when compared with ICC. The finding of a higher estimated maternal blood loss by cesarean section in the DCC group calls for further trials to assess maternal safety of this procedure in this patient population.

A simple scoring system for prediction of IVH in very-low-birth-weight infants

BACKGROUND

To develop a simple scoring system to predict either any or severe IVH in VLBW infants.

METHODS

In this retrospective cohort study, 923 VLBW infants were randomly divided into derivation (n = 431) and validation (n = 492) cohorts. After stepwise multivariable logistic regression analyses, a risk score was assigned to independent predictors.

RESULTS

The overall rates of any and severe IVH were 22.9% and 9.9%. Gestational age, maternal race, location of birth and sex were independent predictors of any IVH (AUC 0.75 in derivation cohort and 0.69 for validation cohort). Birth weight, Apgar score at 1 minute, location of birth and sex were independent predictors of severe IVH (AUC 0.84 in derivation cohort and 0.77 for validation cohort). For any IVH, infants in the high-risk category (total score 4 or 5) had > 50% likelihood of any IVH with a negative predictive value of 82.6%. For severe IVH, the total risk score ranged from 0-8, and infants in high-risk category (total score 6-8) had 30% likelihood of severe IVH with a negative predictive value of 94.9%.

CONCLUSION

We report an easy to calculate, validated scoring system with a high NPV to identify VLBW infants at highest risk of IVH.

IMPACT

We report a simple validated scoring system with a high NPV for prediction of IVH in VLBW infants. The variables in the proposed model are available at birth and unlikely to be influenced by provider bias. This scoring system can identify infants at risk of any and severe IVH, while most previous models predict only severe IVH. This scoring system does not require access to web-based resources. This scoring system can help in employing prevention strategies only for infants at highest risk of IVH and thus eliminate the risks of interventions in a large majority of VLBW infants.

Effect of delayed cord clamping on red blood cell alloimmunization: a retrospective cohort study

BACKGROUND

Although delayed cord clamping has well-known benefits for preterm and term neonates, it has been inadequately assessed in alloimmunized neonates.

OBJECTIVE

This study aimed to evaluate the benefits and risks of delayed cord clamping in alloimmunized neonates.

STUDY DESIGN

This was a retrospective comparative pre-post cohort study conducted from 2003 to 2018 in a tertiary care center in France. All living singleton neonates whose mothers were followed up for red blood cell alloimmunization during gestation and confirmed at birth (N=224) were included. Neonates were either exposed to immediate (n=125) or delayed cord clamping (n=99). Our main outcome was the time from birth to first exchange transfusions and/or transfusions. Secondary outcomes were hemoglobin level at birth, rate of exchange transfusion, number of postnatal transfusions, maximum bilirubin level, and number of phototherapy hours.

RESULTS

Hemoglobin at birth was significantly higher in case of delayed cord clamping (mean difference, 1.7 g/dL; 95% confidence interval, 0.7-2.8). Among infants treated with exchange transfusion or transfusion, the time to initial treatment was higher in case of delayed cord clamping (median difference, 8 days; rate ratio, 1.51; 95% confidence interval, 1.09-2.10). There were no significant differences in the need for exchange transfusion, the number of transfusions, the maximum total bilirubin level, nor the number of phototherapy hours. In the subgroup analysis of neonates needing intrauterine transfusion during pregnancy (ie, severe alloimmunization), neonates had a lower rate of exchange transfusion in case of delayed cord clamping (odds ratio, 0.36; 95% confidence interval, 0.15-0.82).

CONCLUSION

Our results indicate a benefit of delayed cord clamping in alloimmunization, regardless of pathology severity, without increased risk of jaundice.

Alternatives to neonatal intubation

Opportunities to learn and maintain competence in neonatal intubation have decreased. As many clinicians providing care to the newborn infant are not skilled in intubation, alternative strategies are critical. Most preterm infants breathe spontaneously, and require stabilisation rather than resuscitation at birth. Use of tactile stimulation, deferred cord clamping, and avoidance of hypoxia can help optimise breathing for these infants. Nasal devices appear a promising alternative to the face mask for early provision of respiratory support. In term and near-term infants, supraglottic airways may be the most effective initial approach to resuscitation. Use of supraglottic airways during resuscitation can be taught to a range of providers, and may reduce need for intubation. While face mask ventilation is an important skill, it is challenging to perform effectively. Identification of the best approach to training the use of these devices during neonatal resuscitation remains an important priority.

Strengthening Reporting of Neonatal Trials

BACKGROUND AND OBJECTIVES

There is variability in the selection and reporting of outcomes in neonatal trials with key information frequently omitted. This can impact applicability of trial findings to clinicians, families, and caregivers, and impair evidence synthesis. The Neonatal Core Outcomes Set describes outcomes agreed as clinically important that should be assessed in all neonatal trials, and Consolidated Standards of Reporting Trials (CONSORT)-Outcomes 2022 is a new, harmonized, evidence-based reporting guideline for trial outcomes. We reviewed published trials using CONSORT-Outcomes 2022 guidance to identify exemplars of neonatal core outcome reporting to strengthen description of outcomes in future trial publications.

METHODS

Neonatal trials including >100 participants per arm published between 2015 to 2020 with a primary outcome included in the Neonatal Core Outcome Set were identified. Primary outcome reporting was reviewed using CONSORT 2010 and CONSORT-Outcomes 2022 guidelines by assessors recruited from Cochrane Neonatal. Examples of clear and complete outcome reporting were identified with verbatim text extracted from trial reports.

RESULTS

Thirty-six trials were reviewed by 39 assessors. Examples of good reporting for CONSORT 2010 and CONSORT-Outcomes 2022 criteria were identified and subdivided into 3 outcome categories: "survival," "short-term neonatal complications," and "long-term developmental outcomes" depending on the core outcomes to which they relate. These examples are presented to strengthen future research reporting.

CONCLUSIONS

We have identified examples of good trial outcome reporting. These illustrate how important neonatal outcomes should be reported to meet the CONSORT 2010 and CONSORT-Outcomes 2022 guidelines. Emulating these examples will improve the transmission of information relating to outcomes and reduce associated research waste.

Optimizing transition: Providing oxygen during intact cord resuscitation

Delayed clamping and cutting of the umbilical cord at birth is standard practice for management for all newborns. Preterm infants may additionally benefit from a combination of ventilation and oxygen provision during intact cord resuscitation. This review highlights both the potential benefits of such a combined approach and the need for further rigorous studies, including randomized controlled trials, of delivery room management in this population.

To guide future practice, perinatal trials should be much larger, simpler and less fragile with close to 100% ascertainment of mortality and other key outcomes

The Australian Placental Transfusion Study (APTS) randomised 1,634 fetuses to delayed (≥60 s) versus immediate (≤10 s) clamping of the umbilical cord. Systematic reviews with meta-analyses, including this and similar trials, show that delaying clamping in preterm infants reduces mortality and need for blood transfusions. Amongst 1,531 infants in APTS followed up at two years, aiming to delay clamping for 60 s or more reduced the relative risk of the primary composite outcome of death or disability by 17% (p = 0.01). However, this result is fragile because nominal statistical significance (p < 0.05) would be abolished by only 2 patients switching from a non-event to an event, and the primary composite outcome was missing in 112 patients (7%). To achieve more robust evidence, any future trials should emulate the large, simple trials co-ordinated from Oxford which reliably identified moderate, incremental improvements in mortality in tens of thousands of participants, with <1% missing data. Those who fund, regulate, and conduct trials that aim to change practice should repay the trust of those who consent to participate by doing everything possible to minimise missing data for key outcomes.

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.

Exposure to umbilical cord management approaches and death or neurodevelopmental impairment at 22-26 months' corrected age after extremely preterm birth

OBJECTIVE

To compare death or severe neurodevelopmental impairment (NDI) at 22-26 months' corrected age (CA) among extremely preterm infants following exposure to different forms of umbilical cord management.

DESIGN

Retrospective study.

SETTING

Eunice Kennedy Shriver National Institute of Child Health and Human Development Neonatal Research Network registry.

PATIENTS

Infants born <27 weeks' gestation in 2016-2018 without severe congenital anomalies who received active treatment after birth and underwent neurodevelopmental assessments between 22 and 26 months' CA.

EXPOSURES

Immediate cord clamping (ICC), delayed cord clamping (DCC) or umbilical cord milking (UCM).

MAIN OUTCOMES AND MEASURE

Primary composite outcome of death or severe NDI at 22-26 months' CA, defined as severe cerebral palsy, Bayley-III cognitive/motor composite score <70, bilateral deafness or blindness; individual components were examined as secondary outcomes. Multivariable regression examined associations, adjusting for risk factors identified a priori and potential confounders. Mediation analysis explored the effect of severe intraventricular haemorrhage (IVH) on the exposure-outcome relationship.

RESULTS

Among 1900 infants, 64.1% were exposed to ICC, 27.8% to DCC and 8.1% to UCM. Compared with ICC-exposed infants, DCC-exposed infants had lower odds of death or severe NDI (adjusted OR 0.64, 95% CI 0.50 to 0.83). No statistically significant differences were observed when comparing UCM with either ICC or DCC, or between secondary outcomes across groups. Association between cord management and the primary outcome was not mediated by severe IVH.

CONCLUSION

Compared with ICC, DCC exposure was associated with lower death or severe NDI at 22-26 months' CA among extremely preterm infants, which was not mediated by severe IVH.

Interventions to Reduce Severe Brain Injury Risk in Preterm Neonates: A Systematic Review and Meta-analysis

Importance

Interventions to reduce severe brain injury risk are the prime focus in neonatal clinical trials.

Objective

To evaluate multiple perinatal interventions across clinical settings for reducing the risk of severe intraventricular hemorrhage (sIVH) and cystic periventricular leukomalacia (cPVL) in preterm neonates.

Data Sources

MEDLINE, Embase, CENTRAL (Cochrane Central Register of Controlled Trials), and CINAHL (Cumulative Index to Nursing and Allied Health Literature) databases were searched from inception until September 8, 2022, using prespecified search terms and no language restrictions.

Study Selection

Randomized clinical trials (RCTs) that evaluated perinatal interventions, chosen a priori, and reported 1 or more outcomes (sIVH, cPVL, and severe brain injury) were included.

Data Extraction and Synthesis

Two co-authors independently extracted the data, assessed the quality of the trials, and evaluated the certainty of the evidence using the Cochrane GRADE (Grading of Recommendations, Assessment, Development, and Evaluation) approach. Fixed-effects pairwise meta-analysis was used for data synthesis.

Main Outcomes and Measures

The 3 prespecified outcomes were sIVH, cPVL, and severe brain injury.

Results

A total of 221 RCTs that assessed 44 perinatal interventions (6 antenatal, 6 delivery room, and 32 neonatal) were included. Meta-analysis showed with moderate certainty that antenatal corticosteroids were associated with small reduction in sIVH risk (risk ratio [RR], 0.54 [95% CI, 0.35-0.82]; absolute risk difference [ARD], -1% [95% CI, -2% to 0%]; number needed to treat [NNT], 80 [95% CI, 48-232]), whereas indomethacin prophylaxis was associated with moderate reduction in sIVH risk (RR, 0.64 [95% CI, 0.52-0.79]; ARD, -5% [95% CI, -8% to -3%]; NNT, 20 [95% CI, 13-39]). Similarly, the meta-analysis showed with low certainty that volume-targeted ventilation was associated with large reduction in risk of sIVH (RR, 0.51 [95% CI, 0.36-0.72]; ARD, -9% [95% CI, -13% to -5%]; NNT, 11 [95% CI, 7-23]). Additionally, early erythropoiesis-stimulating agents (RR, 0.68 [95% CI, 0.57-0.83]; ARD, -3% [95% CI, -4% to -1%]; NNT, 34 [95% CI, 22-67]) and prophylactic ethamsylate (RR, 0.68 [95% CI, 0.48-0.97]; ARD, -4% [95% CI, -7% to 0%]; NNT, 26 [95% CI, 13-372]) were associated with moderate reduction in sIVH risk (low certainty). The meta-analysis also showed with low certainty that compared with delayed cord clamping, umbilical cord milking was associated with a moderate increase in sIVH risk (RR, 1.82 [95% CI, 1.03-3.21]; ARD, 3% [95% CI, 0%-6%]; NNT, -30 [95% CI, -368 to -16]).

Conclusions and Relevance

Results of this study suggest that a few interventions, including antenatal corticosteroids and indomethacin prophylaxis, were associated with reduction in sIVH risk (moderate certainty), and volume-targeted ventilation, early erythropoiesis-stimulating agents, and prophylactic ethamsylate were associated with reduction in sIVH risk (low certainty) in preterm neonates. However, clinicians should carefully consider all of the critical factors that may affect applicability in these interventions, including certainty of the evidence, before applying them to clinical practice.

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.

Cord management strategies in multifetal gestational births

Multifetal gestations are associated with high risks of neonatal mortality and morbidities primarily due to prematurity. Delayed cord clamping and cord milking facilitate the postnatal transition and improve outcomes. Limited evidence shows that delayed cord clamping for 30-60 s and cord milking are feasible without causing harm and potentially beneficial in uncomplicated multifetal deliveries. However, data on maternal bleeding from the limited studies are inconsistent. Based on current knowledge of the risk vs. benefits, it is reasonable to perform delayed cord clamping or cord milking (>28 weeks of gestation) in uncomplicated monochorionic and dichorionic multiples. Clearly defined criteria for suitable candidates, indications for clamping or milking the cord during delivery, and improved obstetric techniques in Cesarean deliveries are critical to minimize risks and optimize neonatal transition. Research is needed to identify safe and optimal cord-management strategies for improving survival and long-term outcomes in this high-risk population.

Evaluating the evidence behind umbilical cord clamping practices in at-risk neonatal populations

Umbilical cord clamping practices impact nearly 140 million births each year. Current evidence has led professional organizations to recommend delayed cord clamping (DCC), as opposed to early cord clamping (ECC), as the standard of care in uncomplicated term and preterm deliveries. However, variability remains in cord management practices for maternal-infant dyads at higher risk of complications. This review examines the current state of evidence on the outcomes of at-risk infant populations receiving differing umbilical cord management strategies. Review of contemporary literature demonstrates members of high-risk neonatal groups, including those affected by small for gestational age (SGA) classification, intrauterine growth restriction (IUGR), maternal diabetes, and Rh-isoimmunization, are frequently excluded from participation in clinical trials of cord clamping strategies. Furthermore, when these populations are included, outcomes are often underreported. Consequently, evidence regarding optimal umbilical cord management in at-risk groups is limited, and further research is needed to guide best clinical practice.

Maternal implications of placental transfusion

Placental transfusion for 30-60 s after delivery is recommended by numerous professional societies and is now a common practice. Numerous studies document neonatal benefit with minimal maternal risk when routine neonatal stabilization and active management of the third stage of labor are undertaken during the period of delayed cord clamping. Maternal outcomes do not show any increased incidence of postpartum hemorrhage, or need for blood product transfusion in the case of vaginal delivery or cesarean section. Fetomaternal hemorrhage is also likely decreased with delayed cord clamping. In the case of fetal anomalies, cord management should be individualized according to each special circumstance, but is unlikely to lead to increased maternal morbidity. While few studies have investigated maternal outcomes with umbilical cord milking, this practice has not been as widely adopted. With careful monitoring of maternal and fetal well-being, a period of placental transfusion following delivery is advised for benefit of the neonate without significant maternal risk.

Implementing intact cord resuscitation in very preterm infants: feasibility and pitfalls

The purpose of this study is to evaluate the feasibility of intact cord resuscitation (ICR) in very preterm infants using a custom-equipped mobile resuscitation trolley (LifeStart^®). We collected maternal and neonatal data of all inborn infants < 32 weeks eligible for ICR per our protocol over 9 months from ICR implementation. We compared rates of ICR between the beginning and the end of the study period. We reviewed maternal and neonatal adverse events related to the procedure and direct outcomes. In order to assess potential quality improvements related to the procedure, we collected the same data in the infants born in the 9-month period preceding ICR implementation. Out of 44 infants born < 32 weeks during the period, 27 were eligible for ICR. Failure to initiate ICR occurred in 9/27, exclusively in the first 5.5 months of the study. In one infant, ICR was interrupted prior to 2 min due to placental abruption. No ICR procedure had to be interrupted due to insufficient cord length. Among the 18 infants who completed ICR, cord clamping timing increased significantly over the study period, from 3.0 [2.5-3.5] to 4.2 min [3.1-8.3] (p = 0.02). No significant maternal blood loss or wound complications were noted. No infant deaths were attributable to failure or direct consequence of ICR, and no infant experienced hypoxic respiratory failure (intubation, FiO2 ≥ 0.4), asphyxia (pH < 7.2), or blood pressure instability (< 2 SD) following stabilization. Hemoglobin level after cord clamping was higher in the ICR cohort than in the pre-implementation group. Seven out of 18 infants exposed to ICR had a temperature < 36.5 °C on admission.   Conclusion: ICR is feasible in very preterm infants. Temperature management requires special attention. Multidisciplinary simulation training before implementation and systematic post-implementation quality improvement meetings may significantly increase ICR program success. What is Known: • Because infants born < 32 weeks often require cardiorespiratory resuscitation at birth, they are not offered delayed cord clamping in the majority of neonatal intensive care units. • Recently, fully equipped mobile trolleys have been developed in order to allow bedside resuscitation with an intact cord. What is New: • Variable timing of cord clamping based on the infant's transition and respiratory stability, i.e., "physiology-based cord clamping," is safely achievable in very preterm infants. • Intact cord resuscitation requires specific equipment, operational protocols, and a high level of preparation from both obstetrical and neonatal teams, with a learning curve that can be streamlined by multidisciplinary simulation training.

Cardiac and cerebral hemodynamics with umbilical cord milking compared with early cord clamping: A randomized cluster crossover trial

OBJECTIVE

A large, randomized cluster cross-over trial (N = 1730) comparing intact umbilical cord milking (UCM) to early cord clamping (ECC) in non-vigorous near-term/term newborns demonstrated a reduction in cardiorespiratory interventions at birth and less moderate to severe hypoxic ischemic encephalopathy. We evaluated changes in cerebral tissue oxygenation (StO2), pulse oximetry (SpO2), pulse rate and fraction of inspired oxygen (FiO2) during the first 10 min of life in a subset of infants enrolled in the parent trial.

STUDY DESIGN

Infants enrolled in the Milking in Non-Vigorous Infants trial that had StO2 monitoring at birth were included in the sub-study conducted at 3 hospitals the US and Canada. A near-infrared spectroscopy sensor, pulse oximeter and electrocardiogram electrodes were placed. Pulse rate, StO2, SpO2, and FiO2 were collected for the first 10 min after birth. Longitudinal models were used to compare effects of UCM and ECC.

RESULTS

Thirty-four infants had StO2 data. Fifteen of these infants received UCM and 19 had ECC. Infants receiving UCM had similar heart rates, SpO2, and StO2 values, but were exposed to less FiO2 over the first 10 min of life than infants with ECC (0.26 ± 0.12 vs. 0.81 ± 0.05 at 10 min).

CONCLUSION

Non-vigorous term/near term infants who received UCM at birth required lower FiO2 after delivery when compared to infants who umbilical cords were clamped soon after birth while achieving similar peripheral and cerebral oxygenation. Cord milking may be a potential option for placental transfusion in non-vigorous near term/term infants when delayed cord clamping cannot be performed.

Cardiac Asystole at Birth Re-Visited: Effects of Acute Hypovolemic Shock

Births involving shoulder dystocia or tight nuchal cords can deteriorate rapidly. The fetus may have had a reassuring tracing just before birth yet may be born without any heartbeat (asystole). Since the publication of our first article on cardiac asystole with two cases, five similar cases have been published. We suggest that these infants shift blood to the placenta due to the tight squeeze of the birth canal during the second stage which compresses the cord. The squeeze transfers blood to the placenta via the firm-walled arteries but prevents blood returning to the infant via the soft-walled umbilical vein. These infants may then be born severely hypovolemic resulting in asystole secondary to the loss of blood. Immediate cord clamping (ICC) prevents the newborn's access to this blood after birth. Even if the infant is resuscitated, loss of this large amount of blood volume may initiate an inflammatory response that can enhance neuropathologic processes including seizures, hypoxic-ischemic encephalopathy (HIE), and death. We present the role of the autonomic nervous system in the development of asystole and suggest an alternative algorithm to address the need to provide these infants intact cord resuscitation. Leaving the cord intact (allowing for return of the umbilical cord circulation) for several minutes after birth may allow most of the sequestered blood to return to the infant. Umbilical cord milking may return enough of the blood volume to restart the heart but there are likely reparative functions that are carried out by the placenta during the continued neonatal-placental circulation allowed by an intact cord.

Bronchopulmonary Dysplasia in Extremely Premature Infants: A Scoping Review for Identifying Risk Factors

BACKGROUND

Over the years, bronchopulmonary dysplasia (BPD) affects the pulmonary function of infants, resulting in chronic health burdens for infants and their families. The aim of this scoping review was to screen available evidence regarding perinatal risk factors associated with the development and severity of BPD.

METHODS

The eligibility criteria of the studies were year of publication between 2016 and 2021; setting of a developed country; English or Japanese as the study language; and randomized controlled, cohort, or case-control design. The titles and abstracts of the studies were screened by independent reviewers.

RESULTS

Of 8189 eligible studies, 3 were included for severe BPD and 26 were included for moderate BPD. The risk factors for severe BPD were male sex, iatrogenic preterm birth, maternal hypertensive disorders of pregnancy (HDP), low gestational age, small-for-gestational-age (SGA) birth weight, mechanical ventilation on day 1, and need for patent ductus arteriosus (PDA) management. The risk factors for moderate or severe BPD included male sex, premature rupture of membranes, clinical chorioamnionitis, maternal HDP, SGA birth weight, bubbly/cystic appearance on X-ray, and PDA management.

CONCLUSIONS

We identified several risk factors for BPD. We plan to confirm the validity of the new classification using the existing dataset.

The Short and Long Term Consequences of Delayed Cord Clamping on Late Pre-Term Infants

Objective

To explore the effect of delayed cord clamping on preterm infants.

Methods

A retrospective analysis was conducted using the clinical data of 163 preterm infants with a gestational age of 34-36 weeks + 6 who were admitted to the neonatology department within 2 hours after birth. The blood routine examination indices within 2 hours and at 3-5 days after birth, the biochemical indices and arterial blood gas (ABG) indices within 2 hours after birth, and the hemoglobin level 5-6 months after birth were compared between the early cord clamping (ECC) group and the delayed cord clamping (DCC) group.

Results

Compared with the ECC group, the DCC group had significantly higher venous blood levels of red blood cells, hemoglobin, and hematocrit within 2 hours and at 3-5 days after birth. The ABG bicarbonate (HCO₃) level within 2 hours after birth was obviously higher in the DCC group than in the ECC group, and the ABG absolute base excess(BE) and lactate levels were lower in the DCC group than in the ECC group (P < 0.05). There was no significant difference between the two groups in the incidence of hypothermia, hypoglycemia, respiratory distress, septicemia, feeding intolerance, polycythemia, and hyperbilirubinemia requiring phototherapy during hospitalization (P > 0.05). Compared with the ECC group, the DCC group had a significantly higher venous blood hemoglobin level 5-6 months after birth. The incidence of anemia in the DCC group was significantly lower than in the ECC group (P < 0.05).

Conclusion

Delayed cord clamping can significantly increase the hemoglobin levels of preterm infants at birth and at 5-6 months after birth and can improve the oxygen circulation supply to the organs of such infants. Therefore, delayed cord clamping can improve the prognosis of preterm infants.

Umbilical cord milking-benefits and risks

The most common methods for providing additional placental blood to a newborn are delayed cord clamping (DCC) and umbilical cord milking (UCM). However, DCC carries the potential risk of hypothermia due to extended exposure to the cold environment in the operating room or delivery room, as well as a delay in performing resuscitation. As an alternative, umbilical cord milking (UCM) and delayed cord clamping with resuscitation (DCC-R) have been studied, as they allow for immediate resuscitation after birth. Given the relative ease of performing UCM compared to DCC-R, UCM is being strongly considered as a practical option in non-vigorous term and near-term neonates, as well as preterm neonates requiring immediate respiratory support. However, the safety profile of UCM, particularly in premature newborns, remains a concern. This review will highlight the currently known benefits and risks of umbilical cord milking and explore ongoing studies.

Integrated review of the knowledge, attitudes, and practices of maternity health care professionals concerning umbilical cord clamping

BACKGROUND

Umbilical cord clamp timing has implications for newborn health, which include increased iron stores up to 6 months of age. National and International cord clamping guidelines differ as do health professionals' practices. The rationale for differences in cord clamping practice is unclear.

AIMS AND OBJECTIVE

Studies on the knowledge, attitudes, and practices of maternity health care professionals about cord clamp timing were synthesized. Similarities and differences between professional groups and understanding of the optimal timing of cord clamp timing for term newborns were compared.

METHODS

An integrative review was undertaken. PubMed, Scopus, MIDIRS, CINAHL, and Google Scholar were searched. Publication date limits were set between January 2007 and December 2020. Quality appraisal was undertaken using the Critical Appraisal Skills Program (CASP) tools.

RESULTS

Eighteen studies met inclusion criteria, as they included primary research studies that investigated maternity health care professionals' knowledge, attitudes, and practices about umbilical cord clamping, and were written in English. Four main subject areas were identified: a) knowledge of optimal cord clamp timing; b) attitudes and perceptions of early vs deferred cord clamping; c) cord clamping practice; and d) rationale for cord clamping practice.

CONCLUSIONS

Different attitudes and practices were identified between midwifery and medical professionals in relation to cord clamp timing together with health professional knowledge and practice gaps pertaining to optimal cord clamp timing. Contemporary evidence should inform guidelines for clinical practice and be embedded into maternity health professional curricula and professional development programs.

Heterogeneity in pragmatic randomised trials: sources and management

BACKGROUND

Pragmatic trials aim to generate evidence to directly inform patient, caregiver and health-system manager policies and decisions. Heterogeneity in patient characteristics contributes to heterogeneity in their response to the intervention. However, there are many other sources of heterogeneity in outcomes. Based on the expertise and judgements of the authors, we identify different sources of clinical and methodological heterogeneity, which translate into heterogeneity in patient responses-some we consider as desirable and some as undesirable. For each of them, we discuss and, using real-world trial examples, illustrate how heterogeneity should be managed over the whole course of the trial.

MAIN TEXT

Heterogeneity in centres and patients should be welcomed rather than limited. Interventions can be flexible or tailored and control interventions are expected to reflect usual care, avoiding use of a placebo. Co-interventions should be allowed; adherence should not be enforced. All these elements introduce heterogeneity in interventions (experimental or control), which has to be welcomed because it mimics reality. Outcomes should be objective and possibly routinely collected; standardised assessment, blinding and adjudication should be avoided as much as possible because this is not how assessment would be done outside a trial setting. The statistical analysis strategy must be guided by the objective to inform decision-making, thus favouring the intention-to-treat principle. Pragmatic trials should consider including process analyses to inform an understanding of the trial results. Needed data to conduct these analyses should be collected unobtrusively. Finally, ethical principles must be respected, even though this may seem to conflict with goals of pragmatism; consent procedures could be incorporated in the flow of care.

Delayed cord clamping practice at birth: A narrative review of literature

BACKGROUND

Anaemia in infants is a major public health concern particularly in low and middle-income countries. Delayed cord clamping (DCC) has been advocated as a strategy to decrease iron deficiency anaemia in infants because of the benefits that come with placental transfusion. Despite the documented benefits of delayed cord clamping in preventing anaemia the current practices of delayed cord clamping by midwives and obstetricians across countries and in different contexts is unclear. This narrative review assesses the literature on delayed cord clamping practices published from 2013 to February 2022, in order to examine current practice in birth units globally, and with a focus in low and middle-income countries (LMICs).

METHOD

A search of four bibliographic databases Medline, Scopus (Elsevier), ProQuest, CINAHL and two network and search engines, Wiley and Google Scholar, was undertaken from 2013 to February 2022 using key terms related to delayed cord clamping and immediate cord clamping. A snowball method as well as backward and forward reference checking was also undertaken.

RESULTS

The search strategy identified 10 studies on umbilical cord clamping practices by midwives and obstetricians. Only two studies were conducted in low and middle-income countries.

CONCLUSION

Despite the potential benefits of DCC in reducing anaemia, particularly in low and middle-income countries where the burden of anaemia is a public health concern, there is a paucity of literature on current DCC practices by obstetricians and midwives. Research to establish current DCC practices in these countries is needed to address this gap in the literature.

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.

Physiological-based cord clamping in very preterm infants: the Aeration, Breathing, Clamping 3 (ABC3) trial-study protocol for a multicentre randomised controlled trial

BACKGROUND

International guidelines recommend delayed umbilical cord clamping (DCC) up to 1 min in preterm infants, unless the condition of the infant requires immediate resuscitation. However, clamping the cord prior to lung aeration may severely limit circulatory adaptation resulting in a reduction in cardiac output and hypoxia. Delaying cord clamping until lung aeration and ventilation have been established (physiological-based cord clamping, PBCC) allows for an adequately established pulmonary circulation and results in a more stable circulatory transition. The decline in cardiac output following time-based delayed cord clamping (TBCC) may thus be avoided. We hypothesise that PBCC, compared to TBCC, results in a more stable transition in very preterm infants, leading to improved clinical outcomes. The primary objective is to compare the effect of PBCC on intact survival with TBCC.

METHODS

The Aeriation, Breathing, Clamping 3 (ABC3) trial is a multicentre randomised controlled clinical trial. In the interventional PBCC group, the umbilical cord is clamped after the infant is stabilised, defined as reaching heart rate > 100 bpm and SpO₂ > 85% while using supplemental oxygen < 40%. In the control TBCC group, cord clamping is time based at 30-60 s. The primary outcome is survival without major cerebral and/or intestinal injury. Preterm infants born before 30 weeks of gestation are included after prenatal parental informed consent. The required sample size is 660 infants.

DISCUSSION

The findings of this trial will provide evidence for future clinical guidelines on optimal cord clamping management in very preterm infants at birth.

TRIAL REGISTRATION

ClinicalTrials.gov NCT03808051. First registered on January 17, 2019.

Placental transfusion during neonatal resuscitation in an asphyxiated preterm model

BACKGROUND

Neonatal Resuscitation Program does not recommend placental transfusion in depressed preterm neonates.

METHODS

Our objectives were to study the effect of delayed cord clamping (DCC) with ventilation for 5 min (DCCV, n-5), umbilical cord milking (UCM) without ventilation (n-6), UCM with ventilation (UCMV, n-6), early cord clamping followed by ventilation (ECCV, n-6) on red cell volume (RCV), and hemodynamic changes in asphyxiated preterm lambs. Twenty-three preterm lambs at 127-128 days gestation were randomized to DCCV, UCM, UCMV, and ECCV. We defined asphyxia as heart rate <100/min.

RESULTS

The UCMV had the highest neonatal RCV as a percentage of fetoplacental volume compared to the other groups (UCMV 85.5 ± 10%, UCM 72 ± 10%, ECCV 65 ± 14%, DCCV 61 ± 10%, p < 0.01). The DCCV led to better ventilation (66 ± 1 mmHg) and higher pulmonary blood flow (75 ± 24 ml/kg/min). The carotid flow was significantly higher in UCM without ventilation. The fluctuations in carotid flow with milking were 25 ± 6% higher from baseline during UCM, compared to 6 ± 3% in UCMV (p < 0.01).

CONCLUSIONS

Cord milking with ventilation led to higher RCV than other interventions. Ventilation during cord milking reduced fluctuation in carotid flow compared to UCM alone. DCCV led to better ventilation and pulmonary blood flow but did not increase RCV.

IMPACT

The best practice of placental transfusion in a depressed preterm neonate remains unknown. Ventilation with an intact cord improves gas exchange and hemodynamics in an asphyxiated preterm model. Cord milking without ventilation led to lower red cell volume but higher carotid blood flow fluctuations compared to milking with ventilation. Our data can be translated to bedside and could impact preterm resuscitation.

Protocol for a Nested, Retrospective Study of the Australian Placental Transfusion Study Cohort

Background

Neonates, particularly if born preterm or with congenital anomalies, are among the pediatric patients most likely to need blood transfusion. However, they are also particularly vulnerable to adverse consequences of blood transfusion. Aiming to clamp the umbilical cord for at least a minute after birth is a simple safe procedure that is being increasingly adopted worldwide, although may be associated with increased rates of polycythemia and jaundice. It may also reduce the proportion of preterm babies who need a blood transfusion. The mechanisms for this are not fully understood. Potential mechanisms could include an increased volume of blood transfusion from the placenta to the baby after birth, and an overall reduction in the severity of illness in the first weeks after birth, which could lead to fewer blood tests and greater tolerance of anemia, or enhanced erythropoiesis.

Objectives

To investigate the mechanism behind the reduced need for blood transfusions after deferral of cord clamping.

Methodology

This protocol outlines the methods and data analysis plan for a study using nested retrospective data from a large randomized trial combined with additional data collected from patient medical and pathology records. The additional data items to be collected all relate to the receipt of transfusion and the factors that affect the risk for transfusion in preterm babies. The analysis will include all randomized babies from Australia and New Zealand for whom data are available. Causal mediation analysis is planned to estimate the effects of mediators on the relationship between the timing of cord clamping and the need for blood transfusion. The analysis is designed to discern whether initial severity of illness or the magnitude of placental transfusion mediates red blood cell transfusion dependence.

Anticipated outcomes and dissemination

We expect the study will identify potential strategies for reducing blood transfusions and associated negative outcomes in preterm infants. This will be relevant to researchers, clinicians, and parents. The results will be disseminated through publications, presentations, and inclusion in evidence-based guidelines.

A Survey on Current Practices of Umbilical Cord Clamping in Malaysia

Background

Delayed cord clamping (DCC) has been demonstrated to have significant benefits in reducing the incidence of intraventricular hemorrhage, blood transfusion and neonatal mortality in preterm neonates and improving hemodynamic and long-term neurodevelopment among term infants. There is no clear guideline on umbilical cord clamping (UCC) practices in Malaysia.

Objective

The aim of this survey was to assess the knowledge and practice of DCC among obstetric doctors and midwives in Malaysia, and pediatric colleagues who witness the delivery.

Method

This is a cross-sectional survey conducted in childbirth facilities in Malaysia from October 2020 to January 2021. A convenient snowball sampling was adopted. A validated questionnaire was disseminated to practicing obstetric and pediatric doctors and midwives electronically via email and WhatsApp using Google Form. The data were analyzed using descriptive and analytical statistics.

Results

A total of 327 respondents completed the questionnaires, comprising 206 obstetric doctors, 72 pediatric doctors and 49 midwives. The majority of respondents were specialists or higher in rank (53.2%). Only 29% reported the existence of guidelines on UCC in their place of work. Midwives (P = 0.003) and staff of lower ranks and level of education (P < 0.001) appeared to be more aware of the existence of a UCC guideline. Most respondents had positive knowledge of DCC for both term and preterm neonates. A large proportion (82%) of respondents agreed that DCC helped increase neonatal iron stores, and was good for both preterm (70.7%) and term (76.2%) neonates not requiring positive pressure ventilation. Doctors, specialists, those who are 40 years old and above, and those who have been in service for at least 10 years were found to have better knowledge regarding DCC (P < 0.05).

Conclusion

The awareness and practice of obstetric, pediatric and midwifery staff of guidelines on UCC were less than satisfactory. Even though most respondents have good knowledge and positive perception regarding benefits of DCC, these were not translated into their routine practice. Hence, a national guideline emphasizing the benefits of DCC should be made available in all childbirth facilities.

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.

[Influence of umbilical cord milking versus delayed cord clamping on the early prognosis of preterm infants with a gestational age of <34 weeks: a Meta analysis]

OBJECTIVES

To study the influence of umbilical cord milking versus delayed cord clamping on the early prognosis of preterm infants with a gestational age of <34 weeks.

METHODS

PubMed, Web of Science, Embase, the Cochrane Library, CINAHL, China National Knowledge Infrastructure, Wanfang Data, Weipu Database, and SinoMed were searched for randomized controlled trials on umbilical cord milking versus delayed cord clamping in preterm infants with a gestational age of <34 weeks published up to November 2021. According to the inclusion and exclusion criteria, two researchers independently performed literature screening, quality evaluation, and data extraction. Review Manger 5.4 was used for Meta analysis.

RESULTS

A total of 11 articles were included in the analysis, with 1 621 preterm infants in total, among whom there were 809 infants in the umbilical cord milking group and 812 in the delayed cord clamping group. The Meta analysis showed that compared with delayed cord clamping, umbilical cord milking increased the mean blood pressure after birth (weighted mean difference=3.61, 95%CI: 0.73-6.50, P=0.01), but it also increased the incidence rate of severe intraventricular hemorrhage (RR=1.83, 95%CI: 1.08-3.09, P=0.02). There were no significant differences between the two groups in hemoglobin, hematocrit, blood transfusion rate, proportion of infants undergoing phototherapy, bilirubin peak, and incidence rates of complications such as periventricular leukomalacia and necrotizing enterocolitis (P>0.05).

CONCLUSIONS

Compared with delayed cord clamping, umbilical cord milking may increase the risk of severe intraventricular hemorrhage in preterm infants with a gestational age of <34 weeks; however, more high-quality large-sample randomized controlled trials are needed for further confirmation.

Effect of Delayed Umbilical Cord Clamping on Hemodynamic Instability in Preterm Neonates below 35 Weeks

INTRODUCTION

Delaying umbilical cord clamping facilitates postnatal transition in neonates but evidence on its effect in reducing hemodynamic instability in preterm neonates is inconclusive.

AIMS

To evaluate delayed cord clamping (DCC) in reducing the incidence of hemodynamic instability in preterm neonates below 35 weeks gestational age admitted to the neonatal intensive care unit.

METHODS

Neonates between 25 weeks and 34 weeks and 6 days gestation were enrolled. Hemodynamic and respiratory parameters were monitored over 48 h. Hemodynamic instability was defined as persistent tachycardia and/or hypotension necessitating therapy.

RESULTS

The DCC cohort included 62 neonates with an equal number in the non-DCC group. The birth weight [mean ± standard deviation (SD)] was 1332.90 ± 390.05 g and the gestational age (mean ± SD) was 31.64 ± 2.52 weeks. Hemodynamic instability was noted in 18/62 (29%) neonates in the DCC cohort and 29/62 (46.7%) in the non-DCC group; relative risk (RR) 0.62 [95% confidence interval (CI) 0.38-0.99] (p = 0.023). The duration of inotrope requirement in the DCC cohort (mean ± SD) was 38.38 ± 16.99 h compared to 49.13 ± 22.90 h in the non-DCC cohort (p = 0.090). Significantly higher systolic, diastolic and mean arterial pressures were noted from 6 h to 48 h in the DCC cohort (p < 0.001). The severity of respiratory distress and FiO2 requirement was also less in the first 24 h. There was no difference in the incidence of patent ductus arteriosus, late-onset sepsis or mortality.

CONCLUSION

Delaying umbilical cord clamping at birth by 60 s resulted in significantly lower hemodynamic instability in the first 48 h and higher blood pressure parameters.

Research in the Delivery Room: Can You Tell Me It's Evolution?

Many of the recommendations for newborn care in the delivery room (DR) are based on retrospective observational studies, preclinical studies of mannequins or animal models, and expert opinion. Conducting DR research is challenging. Many deliveries occur in fraught circumstances with little prior warning, making it difficult to get prospective consent from parents and buy-in from clinicians. Many DR interventions are difficult to mask for the purpose of a clinical trial and it is not easy to identify appropriate outcomes for studies that are sufficiently "short-term" that they are likely to be influenced by the intervention, yet sufficiently "long-term" to be considered clinically important. However, despite these challenges, much information has been accrued from clinical studies in recent years. In this article, we outline our experience of conducting clinical research in the DR. In our initial studies almost 20 years ago, we found wide variation in the equipment used both nationally and internationally, reflecting the paucity of evidence to support practice. This started a journey that has included many observational studies and randomized controlled trials that have attempted to refine how we care for newborn infants in the DR. Each has given further information and, inevitably, raised many more questions about the approach to caring for newborns in the DR.

Guideline No. 424: Umbilical Cord Management in Preterm and Term Infants

OBJECTIVE

To assess the impact of deferred (delayed) cord clamping (DCC) and umbilical cord milking in singleton and twin gestations on maternal and infant mortality and morbidity.

TARGET POPULATION

People who are pregnant with preterm or term singletons or twins.

BENEFITS, HARMS, AND COSTS

In preterm singletons, DCC for (ideally) 60 to 120 seconds, but at least for 30 seconds, reduces infant risk of mortality and morbidity. DCC in preterm twins is associated with some benefits. In term singletons, DCC for 60 seconds improves hematological parameters. In very preterm infants, umbilical cord milking increases risk for intraventricular hemorrhage.

EVIDENCE

Searches of Medline, PubMed, Embase, and the Cochrane Library from inception to March 2020 were undertaken using Medical Subject Heading (MeSH) terms and key words related to deferred cord clamping and umbilical cord milking. This document represents an abstraction of the evidence rather than a methodological review.

VALIDATION METHODS

The authors rated the quality of evidence and strength of recommendations using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach. See online Appendix A (Tables A1 for definitions and A2 for interpretations of strong and conditional [weak] recommendations).

INTENDED USERS

Maternity and newborn care providers.

RECOMMENDATIONS

Controversies in treatment practices of the mother-infant dyad at the limit of viability

In the setting of threatened extreme preterm birth, balancing maternal and fetal risks and benefits in order to choose the best available treatment options is of utmost importance. Inconsistency in treatment practices for infants born between 22 and 24 weeks of gestatotional age may account for inter-hospital variation in survival rates with and without impairment. Most importantly, non-biased and accurate information must be presented to the family as soon as extremely preterm birth is suspected, including counseling on morbidities and mortality associated with delivery at the limits of viability. This review will focus on different therapeutic medical and surgical practices available for threatened extremely preterm birth to improve fetal and maternal outcomes while highlighting the importance of patient-centered approaches.