Cord milking versus immediate clamping in preterm infants: a randomised controlled trial

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.

[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.

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.

Hemodynamic Changes with Umbilical Cord Milking in Nonvigorous Newborns: A Randomized Cluster Cross-over Trial

OBJECTIVE

To assess the hemodynamic safety and efficacy of umbilical cord milking (UCM) compared with early cord clamping (ECC) in nonvigorous newborn infants enrolled in a large multicenter randomized cluster-crossover trial.

STUDY DESIGN

Two hundred twenty-seven nonvigorous term or near-term infants who were enrolled in the parent UCM vs ECC trial consented for this substudy. An echocardiogram was performed at 12 ± 6 hours of age by ultrasound technicians blinded to randomization. The primary outcome was left ventricular output (LVO). Prespecified secondary outcomes included measured superior vena cava (SVC) flow, right ventricular output (RVO), peak systolic strain, and peak systolic velocity by tissue Doppler examination of the RV lateral wall and the interventricular septum.

RESULTS

Nonvigorous infants receiving UCM had increased hemodynamic echocardiographic parameters as measured by higher LVO (225 ± 64 vs 187 ± 52 mL/kg/min; P < .001), RVO (284 ± 88 vs 222 ± 96 mL/kg/min; P < .001), and SVC flow (100 ± 36 vs 86 ± 40 mL/kg/min; P < .001) compared with the ECC group. Peak systolic strain was lower (-17 ± 3 vs -22 ± 3%; P < .001), but there was no difference in peak tissue Doppler flow (0.06 m/s [IQR, 0.05-0.07 m/s] vs 0.06 m/s [IQR, 0.05-0.08 m/s]).

CONCLUSIONS

UCM increased cardiac output (as measured by LVO) compared with ECC in nonvigorous newborns. Overall increases in measures of cerebral and pulmonary blood flow (as measured by SVC and RVO flow, respectively) may explain improved outcomes associated with UCM (less cardiorespiratory support at birth and fewer cases of moderate-to-severe hypoxic ischemic encephalopathy) among nonvigorous newborn infants.

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.

Umbilical Cord Milking in Extremely Preterm Infants: A Randomized Controlled Trial Comparing Cord Milking with Immediate Cord Clamping

OBJECTIVE

This study aimed to assess potential benefits of umbilical cord milking (UCM) when compared with immediate cord clamping (ICC) in extremely preterm infants.

STUDY DESIGN

This is a single-center, randomized controlled trial of infants 24^0/7 to 27^6/7 weeks' gestation who received UCM versus ICC. In the experimental group, 18 cm of the umbilical cord was milked three times. The primary aim was to assess the initial hemoglobin and to assess the number of blood transfusions received in the first 28 days after birth. Secondary outcomes were also assessed, including intraventricular hemorrhage (IVH). A priori, neurodevelopmental follow-up was planned at 15 to 18 months corrected gestational age (CGA).

RESULTS

Baseline characteristics for 56 enrolled infants were similar in both groups with a mean gestational age of 26.1 ± 1.2 weeks and a mean birth weight of 815 ± 204 g. There were no differences in the mean initial hemoglobin in the UCM group when compared with the ICC group, 13.7 ± 2.0 and 13.8 ± 2.6 g/dL, respectively (p = 0.95), with no differences in median number of blood transfusions after birth between the ICC group and the UCM group, 2 (interquartile range [IQR]: 1-4) versus 2.5 (IQR: 1-5) (p = 0.40). There was also no difference in the rate of severe IVH. At 15 to 18 months CGA, there were no differences in death or disability in the ICC group compared with the UCM group (26 vs. 22%; p = 1.0) and no differences in neurodevelopmental outcomes.

CONCLUSION

In a randomized trial of ICC versus UCM in extremely preterm infants, no differences were seen in initial hemoglobin or number of blood transfusions.

KEY POINTS

· Umbilical cord milking may be an alternative to delayed cord clamping, but its safety and efficacy are not established in extremely premature infants.. · There are minimal available published data on the longer term neurodevelopmental outcomes in extremely premature infants who receive umbilical cord milking compared with immediate clamping.. · We did not find a significant difference in the primary outcomes of initial hemoglobin and blood transfusions between the groups, nor did we find a difference in severe IVH with umbilical cord milking..

Vitamin E and preterm infants

In evaluating vitamin E (VE) nutritional status of preterm infants, it is essential that any data should be compared with those of healthy term infants, and never with those of adults. Moreover, it should be evaluated in terms of gestational age (GA), not birth weight (BW), because placental transfer of most nutrients from mother to fetus is dependent on GA, not BW. Judging from the limited data during the last 75 years, there was no significant correlation between GA and VE concentrations in circulation or in the red blood cells (RBCs), leukocytes, and buccal mucosal cells. In addition, the oxidizability of polyunsaturated fatty acids (PUFAs) in plasma or RBCs, as targets for protection by VE chain-breaking ability, was lower in preterm infants. However, because of the minimal information available about hepatic VE levels, which is considered a key determinant of whole body VE status, the decision on whether VE status of preterm infants is comparable with that of term infants should be postponed. Clinical trials of VE supplementation in preterm infants were repeatedly undertaken to investigate whether VE reduces severity or inhibits development of several diseases specific to preterm infants, namely retinopathy of prematurity (ROP), bronchopulmonary dysplasia (BPD), and germinal matrix hemorrhage - intraventricular hemorrhage (GMH-IVH). Most of these trials resulted in a misfire, with a few exceptions for IVH prevention. However, almost all these studies were performed from 1980s to early 1990s, in the pre-surfactant era, and the study populations were composed of mid-preterm infants with GAs of approximately 30 weeks (wks). There is considerable difference in 'preterm infants' between the pre- and post-surfactant eras; modern neonatal medicine mainly treats preterm infants of 28 wks GA or less. Therefore, these results are difficult to apply in modern neonatal care. Before considering new trials of VE supplementation, we should fully understand modern neonatal medicine, especially the recent method of oxygen supplementation. Additionally, a deeper understanding of recent progress in pathophysiology and therapies for possible target diseases is necessary to decide whether VE administration is still worth re-challenging in modern neonatal intensive care units (NICUs). In this review, we present recent concepts and therapeutic trends in ROP, BPD, and GMH-IVH for those unfamiliar with neonatal medicine. Numerous studies have reported the possible involvement of reactive oxygen species (ROS)-induced damage in relation to supplemental oxygen use, inflammation, and immature antioxidant defense in the development of both BPD and ROP. Various antioxidants effectively prevented the exacerbation of BPD and ROP in animal models. In the future, VE should be re-attempted as a complementary factor in combination with various therapies for BPD, ROP, and GMH-IVH. Because VE is a natural and safe supplement, we are certain that it will attract attention again in preterm medicine.

2021 International Consensus on Cardiopulmonary Resuscitation and Emergency Cardiovascular Care Science With Treatment Recommendations: Summary From the Basic Life Support; Advanced Life Support; Neonatal Life Support; Education, Implementation, and Teams; First Aid Task Forces; and the COVID-19 Working Group

The International Liaison Committee on Resuscitation initiated a continuous review of new, peer-reviewed published cardiopulmonary resuscitation science. This is the fifth annual summary of the International Liaison Committee on Resuscitation International Consensus on Cardiopulmonary Resuscitation and Emergency Cardiovascular Care Science With Treatment Recommendations; a more comprehensive review was done in 2020. This latest summary addresses the most recently published resuscitation evidence reviewed by International Liaison Committee on Resuscitation task force science experts. Topics covered by systematic reviews in this summary include resuscitation topics of video-based dispatch systems; head-up cardiopulmonary resuscitation; early coronary angiography after return of spontaneous circulation; cardiopulmonary resuscitation in the prone patient; cord management at birth for preterm and term infants; devices for administering positive-pressure ventilation at birth; family presence during neonatal resuscitation; self-directed, digitally based basic life support education and training in adults and children; coronavirus disease 2019 infection risk to rescuers from patients in cardiac arrest; and first aid topics, including cooling with water for thermal burns, oral rehydration for exertional dehydration, pediatric tourniquet use, and methods of tick removal. Members from 6 International Liaison Committee on Resuscitation task forces have assessed, discussed, and debated the quality of the evidence, according to the Grading of Recommendations Assessment, Development, and Evaluation criteria, and their statements include consensus treatment recommendations or good practice statements. Insights into the deliberations of the task forces are provided in Justification and Evidence-to-Decision Framework Highlights sections. In addition, the task forces listed priority knowledge gaps for further research.

2021 International Consensus on Cardiopulmonary Resuscitation and Emergency Cardiovascular Care Science With Treatment Recommendations: Summary From the Basic Life Support; Advanced Life Support; Neonatal Life Support; Education, Implementation, and Teams; First Aid Task Forces; and the COVID-19 Working Group

The International Liaison Committee on Resuscitation initiated a continuous review of new, peer-reviewed published cardiopulmonary resuscitation science. This is the fifth annual summary of the International Liaison Committee on Resuscitation International Consensus on Cardiopulmonary Resuscitation and Emergency Cardiovascular Care Science With Treatment Recommendations; a more comprehensive review was done in 2020. This latest summary addresses the most recently published resuscitation evidence reviewed by International Liaison Committee on Resuscitation task force science experts. Topics covered by systematic reviews in this summary include resuscitation topics of video-based dispatch systems; head-up cardiopulmonary resuscitation; early coronary angiography after return of spontaneous circulation; cardiopulmonary resuscitation in the prone patient; cord management at birth for preterm and term infants; devices for administering positive-pressure ventilation at birth; family presence during neonatal resuscitation; self-directed, digitally based basic life support education and training in adults and children; coronavirus disease 2019 infection risk to rescuers from patients in cardiac arrest; and first aid topics, including cooling with water for thermal burns, oral rehydration for exertional dehydration, pediatric tourniquet use, and methods of tick removal. Members from 6 International Liaison Committee on Resuscitation task forces have assessed, discussed, and debated the quality of the evidence, according to the Grading of Recommendations Assessment, Development, and Evaluation criteria, and their statements include consensus treatment recommendations or good practice statements. Insights into the deliberations of the task forces are provided in Justification and Evidence-to-Decision Framework Highlights sections. In addition, the task forces listed priority knowledge gaps for further research.

A 20-cm cut umbilical cord milking may not benefit the preterm infants < 30 week's gestation: A randomized clinical trial

BACKGROUND/PURPOSE

To evaluate whether a shorter length (20 cm) of C-UCM has potential benefits, compared to immediate cord clamping (ICC), in very preterm babies.

METHODS

Inborn preterm infants less than 30 weeks of gestational age (GA) were randomly assigned to the 20-cm C-UMC and ICC groups. The primary outcome was the need for packed red blood cell (pRBC) transfusion before the 21st day of life. The secondary outcomes were short- and long-term outcomes related to premature birth.

RESULTS

Seventy-six neonates were randomized to the two groups. GA were 27.2 ± 1.8 and 27.5 ± 1.7 weeks (p = 0.389) and birth weights were 987 ± 269 and 1023 ± 313 g (p = 0.601) in the 20-cm C-UCM and ICC groups, respectively. There was no significant difference between the groups in terms of the need for pRBC transfusion before the 21st day of life (59.4% versus 71.8%, adjusted odds ratio [aOR] 0.311, 95% confidence interval [CI] 0.090-1.079). An increased prevalence of late-onset sepsis was observed in the 20-cm C-UCM group compared to the ICC group (21.6% versus 5.1%, aOR 5.434, 95% CI 1.033-23.580). The mortality rates were 13.5% and 2.6% in the 20-cm C-UCM and ICC groups, respectively (aOR 5.339, 95% CI 0.563-50.626). The neurodevelopmental outcomes at 2 years of corrected age between the groups were also not statistically significant.

CONCLUSION

A 20-cm C-UCM showed no effect on reducing the incidence of pRBC transfusion in preterm babies with GA less than 30 weeks compared with ICC in this small-scale randomized controlled trial.

Eligibility Criteria and Representativeness of Randomized Clinical Trials That Include Infants Born Extremely Premature: A Systematic Review

OBJECTIVE

To assess the eligibility criteria and trial characteristics among contemporary (2010-2019) randomized clinical trials (RCTs) that included infants born extremely preterm (<28 weeks of gestation) and to evaluate whether eligibility criteria result in underrepresentation of high-risk subgroups (eg, infants born at <24 weeks of gestation).

STUDY DESIGN

PubMed and Scopus were searched January 1, 2010, to December 31, 2019, with no language restrictions. RCTs with mean or median gestational ages at birth of <28 weeks of gestation were included. The study followed the PRISMA guidelines; outcomes were registered prospectively. Data extraction was performed independently by multiple observers. Study quality was evaluated using a modified Jadad scale.

RESULTS

Among RCTs (n = 201), 32 552 infants were included. Study participant characteristics, interventions, and outcomes were highly variable. A total of 1603 eligibility criteria were identified; rationales were provided for 18.8% (n = 301) of criteria. Fifty-five RCTs (27.4%) included infants <24 weeks of gestation; 454 (1.4%) infants were identified as <24 weeks of gestation.

CONCLUSIONS

The present study identifies sources of variability across RCTs that included infants born extremely preterm and reinforces the critical need for consistent and transparent policies governing eligibility criteria.

Association of Umbilical Cord Management Strategies With Outcomes of Preterm Infants: A Systematic Review and Network Meta-analysis

IMPORTANCE

It is unclear which umbilical cord management strategy is the best for preventing mortality and morbidities in preterm infants.

OBJECTIVE

To systematically review and conduct a network meta-analysis comparing 4 umbilical cord management strategies for preterm infants: immediate umbilical cord clamping (ICC), delayed umbilical cord clamping (DCC), umbilical cord milking (UCM), and UCM and DCC.

DATA SOURCES

PubMed, Embase, CINAHL, and Cochrane CENTRAL databases were searched from inception until September 11, 2020.

STUDY SELECTION

Randomized clinical trials comparing different umbilical cord management strategies for preterm infants were included.

DATA EXTRACTION AND SYNTHESIS

Data were extracted for bayesian random-effects meta-analysis to estimate the relative treatment effects (odds ratios [OR] and 95% credible intervals [CrI]) and surface under the cumulative ranking curve values.

MAIN OUTCOMES AND MEASURES

The primary outcome was predischarge mortality. The secondary outcomes were intraventricular hemorrhage, severe intraventricular hemorrhage, need for packed red blood cell transfusion, and other neonatal morbidities. Confidence in network meta-analysis software was used to assess the quality of evidence and grade outcomes.

RESULTS

Fifty-six studies enrolled 6852 preterm infants. Compared with ICC, DCC was associated with lower odds of mortality (22 trials, 3083 participants; 7.6% vs 5.0%; OR, 0.64; 95% CrI, 0.39-0.99), intraventricular hemorrhage (25 trials, 3316 participants; 17.8% vs 15.4%; OR, 0.73; 95% CrI, 0.54-0.97), and need for packed red blood cell transfusion (18 trials, 2904 participants; 46.9% vs 38.3%; OR, 0.48; 95% CrI, 0.32-0.66). Compared with ICC, UCM was associated with lower odds of intraventricular hemorrhage (10 trials, 645 participants; 22.5% vs 16.2%; OR, 0.58; 95% CrI, 0.38-0.84) and need for packed red blood cell transfusion (9 trials, 688 participants; 47.3% vs 32.3%; OR, 0.36; 95% CrI, 0.23-0.53), with no significant differences for other secondary outcomes. There was no significant difference between UCM and DCC for any outcome.

CONCLUSIONS AND RELEVANCE

Compared with ICC, DCC was associated with the lower odds of mortality in preterm infants. Compared with ICC, DCC and UCM were associated with reductions in intraventricular hemorrhage and need for packed red cell transfusion. There was no significant difference between UCM and DCC for any outcome. Further studies directly comparing DCC and UCM are needed.

Interventions to minimize blood loss in very preterm infants-A systematic review and meta-analysis

Blood loss in the first days of life has been associated with increased morbidity and mortality in very preterm infants. In this systematic review we included randomized controlled trials comparing the effects of interventions to preserve blood volume in the infant from birth, reduce the need for sampling, or limit the blood sampled. Mortality and major neurodevelopmental disabilities were the primary outcomes. Included studies underwent risk of bias-assessment and data extraction by two review authors independently. We used risk ratio or mean difference to evaluate the treatment effect and meta-analysis for pooled results. The certainty of evidence was assessed using GRADE. We included 31 trials enrolling 3,759 infants. Twenty-five trials were pooled in the comparison delayed cord clamping or cord milking vs. immediate cord clamping or no milking. Increasing placental transfusion resulted in lower mortality during the neonatal period (RR 0.51, 95% CI 0.26 to 1.00; participants = 595; trials = 5; I2 = 0%, moderate certainty of evidence) and during first hospitalization (RR 0.70, 95% CI 0.51, 0.96; 10 RCTs, participants = 2,476, low certainty of evidence). The certainty of evidence was very low for the other primary outcomes of this review. The six remaining trials compared devices to monitor glucose levels (three trials), blood sampling from the umbilical cord or from the placenta vs. blood sampling from the infant (2 trials), and devices to reintroduce the blood after analysis vs. conventional blood sampling (1 trial); the certainty of evidence was rated as very low for all outcomes in these comparisons. Increasing placental transfusion at birth may reduce mortality in very preterm infants; However, extremely limited evidence is available to assess the effects of other interventions to reduce blood loss after birth. In future trials, infants could be randomized following placental transfusion to different blood saving approaches. Trial registration: PROSPERO CRD42020159882.

The effect of umbilical cord milking on cerebral blood flow in very preterm infants: a randomized controlled study

OBJECTIVE

To compare the effect of umbilical cord milking (UCM) vs. early cord clamping (ECC) on cerebral blood flow (CBF).

METHOD

Preterm infants <31 weeks' gestation were randomized to receive UCM or ECC at birth. Blood flow velocities and resistive & pulsatility indices of middle and anterior cerebral arteries were measured at 4-6 and 10-12 h after birth as an estimate of CBF.

RESULTS

Randomization allocated 37 infants to UCM and 36 to ECC. Maternal and antenatal variables were similar. There were no significant differences between groups in middle or anterior CBF velocities and resistive indices at either study time point. CBF variables were not correlated with mean blood pressure, systemic blood flow, or intraventricular hemorrhage.

CONCLUSIONS

In very preterm infants, UCM compared with ECC was not shown to change CBF indices during the first 12 h of age or correlate with other hemodynamic measures or with intraventricular hemorrhage.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT01487187.

Comparison of Two Techniques of Superior Vena Cava Flow Measurement in Preterm Infants With Birth Weight <1,250 g in the Transitional Period-Prospective Observational Cohort Study

Objectives: Superior Vena Cava (SVC) flow in neonates measured by the standard approach has been validated by different groups around the world. The modified SVC flow measurement technique was recently suggested. The aim of our study was to evaluate standard and modified technique of echocardiography SVC flow measurement in a cohort of extremely preterm neonates in the immediate postnatal period. Methods: Prospective, observational cohort study in a level III neonatal center. Infants with birth weight <1,250 g were eligible for enrolment. SVC flow was measured by echocardiography using standard and modified methods at 6, 18 and 36 h of age. Our primary outcome was equivalency (using raw bounds of -20 to +20 mL/kg/min difference between the paired measurements), agreement and correlation between standard and modified methods of the SVC flow measurements. Results: Thirty-nine infants were enrolled. The mean gestational age of the cohort was 27.4 (SD 2.1) weeks of postmenstrual age, the mean birth weight was 0.95 kg (SD 0.2). The measurements at 6 and 36 h of age were equivalent as defined in the design of the study (p = 0.003 and p = 0.004 respectively; raw bounds -20 to +20 mL/kg/min). At 6 h of age the mean difference (bias) between the measurements was -0.8 mL/kg/min with 95% limits of agreement -65.0 to 63.4 mL/kg/min. At 18 h of age, the mean difference (bias) between the measurements was +9.5 mL/kg/min, with 95% limits of agreement -79.6 to 98.7 mL/kg/min. At 36 h of age the mean difference (bias) between the measurements was -2.2 mL/kg/min with 95% limits of agreement -73.4 to 69.1 mL/kg/min. There was a weak, but statistically significant correlation between the standard and modified method at 6 h of age (r = 0.39, p = 0.04). Conclusion: Both SVC flow echocardiography measurement techniques yielded clinically equivalent results, however due to wide limits of agreement and poor correlation they do not seem to be interchangeable.

Short-term efficacy of umbilical cord milking in preterm infants: systematic review and meta-analysis

BACKGROUND

To systematically evaluate short-term efficacy of UCM versus other interventions in preterm infants.

METHODS

Six engines were searched until February 2020 for randomized controlled trials (RCTs) assessing UCM versus immediate cord clamping (ICC), delayed cord clamping (DCC), or no intervention. Primary outcomes were overall mortality, intraventricular hemorrhage (IVH), and patent ductus arteriosus (PDA); secondary outcomes were need for blood transfusion, mean blood pressure (MBP), serum hemoglobin (Hb), and ferritin levels. Random-effects meta-analyses were used.

RESULTS

Fourteen RCTs (n = 1708) were included. In comparison to ICC, UCM did not decrease mortality (RR 0.5, 95% CI 0.2-1.1), IVH (RR 0.7, 95% CI 0.5-1.0), or PDA (RR 1.0, 95% CI 0.7-1.5). However, UCM reduced need of blood transfusion (RR 0.5, 95% CI 0.3-0.9) and increased MBP (MD 2.5 mm Hg, 95% CI 0.5-4.5), Hb (MD 1.2 g/dL, 95% CI 0.8-1.6), and ferritin (MD 151.4 ng/dL, 95% CI 59.5-243.3). In comparison to DCC, UCM did not reduce mortality, IVH, PDA, or need of blood transfusion but increased MBP (MD 3.7, 95% CI 0.6-6.9) and Hb (MD 0.3, 95% CI -0.2-0.8). Only two RCTs had high risk of bias.

CONCLUSIONS

UCM did not decrease short-term clinical outcomes in comparison to ICC or DCC in preterm infants. Intermediate outcomes improved significantly with UCM.

IMPACT

In 14 randomized controlled trials (RCTs), umbilical cord milking (UCM) did not reduce mortality, intraventricular hemorrhage, or patent ductus arteriosus compared to immediate (ICC) or delayed cord clamping (DCC). UCM improved mean blood pressure and hemoglobin levels compared to ICC or DCC. In comparison to ICC, UCM reduced the need for blood transfusion. We updated searches until February 2020, stratified by type of control, and performed subgroup analyses. There was low quality of evidence about clinical efficacy of UCM. Most of RCTs had low risk of bias. UCM cannot be recommended as standard of care for preterm infants.

Umbilical cord milking in preterm infants: a systematic review and meta-analysis

OBJECTIVE

To conduct a systematic review and meta-analysis of the efficacy and safety of umbilical cord milking in preterm infants.

DESIGN

Randomised controlled trials comparing umbilical cord milking with delayed cord clamping/immediate cord clamping in preterm infants were identified by searching databases, clinical trial registries and reference list of relevant studies in November 2019. Fixed effects model was used to pool the data on various clinically relevant outcomes.

MAIN OUTCOME MEASURES

Mortality and morbidities in preterm neonates.

RESULTS

Nineteen studies (2014 preterm infants) were included. Five studies (n=922) compared cord milking with delayed cord clamping, whereas 14 studies (n=1092) compared milking with immediate cord clamping. Cord milking, as opposed to delayed cord clamping, significantly increased the risk of intraventricular haemorrhage (grade III or more) (risk ratio (RR): 1.95 (95% CI 1.01 to 3.76), p=0.05). When compared with immediate cord clamping, cord milking reduced the need for packed RBC transfusions (RR:0.56 (95% CI 0.43 to 0.73), p<0.001). There was limited information on long-term neurodevelopmental outcomes. The grade of evidence was moderate or low for the various outcomes analysed.

CONCLUSION

Umbilical cord milking, when compared with delayed cord clamping, significantly increased the risk of severe intraventricular haemorrhage in preterm infants, especially at lower gestational ages. Cord milking, when compared with immediate cord clamping, reduced the need for packed RBC transfusions but did not improve clinical outcomes. Hence, cord milking cannot be considered as placental transfusion strategy in preterm infants based on the currently available evidence.

Umbilical Cord Milking in Infants Born at <37 Weeks of Gestation: A Systematic Review and Meta-Analysis

Umbilical cord milking (UCM) could be an alternative in cases where delayed umbilical cord clamping cannot be performed, therefore our objective was to evaluate the effects of UCM in newborns <37 weeks’ gestation. In this systematic review and meta-analysis, we searched MEDLINE, EMBASE, CINAHL, the Cochrane Database of Clinical Trials, the clinicaltrails.gov database for randomized UCM clinical trials with no language restrictions, which we then compared with other strategies. The sample included 2083 preterm infants. The results of our meta-analysis suggest that UCM in premature infants can reduce the risk of transfusion (relative risk (RR)= 0.78 [95% confidence interval (CI),0.67–0.90]) and increase hemoglobin(pooled weighted mean difference (PWMD)= 0.89 g/L[95%CI 0.55–1.22]) and mean blood pressure (PWMD=1.92 mmHg [95% CI 0.55–3.25]). Conversely, UCM seems to increase the risk of respiratory distress syndrome (RR = 1.54 [95% CI 1.03–2.29]), compared to the control groups. In infants born at <33 weeks, UCM was associated with a reduced risk of transfusion (RR= 0.81 [95%CI 0.66–0.99]), as well as higher quantities of hemoglobin (PWMD= 0.91 g/L[95%CI 0.50–1.32]). UCM reduces the risk of transfusion in preterm infants, and increases initial hemoglobin, hematocrit, and mean blood pressure levels with respect to controls.

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.

Umbilical cord milking reduces the risk of intraventricular hemorrhage in preterm infants born before 32 weeks of gestation

OBJECTIVE

Intraventricular hemorrhage (IVH) is a common complication in extremely preterm infants. We aimed to demonstrate that umbilical cord milking (UCM) would reduce the incidence of IVH in this at risk population.

STUDY DESIGN

We compared the incidence of IVH in a prospective cohort of consecutively born preterm infants <32 weeks' gestation receiving UCM (n = 33) with a historical cohort that underwent immediate cord clamping (ICC) (n = 36).

RESULTS

No significant differences regarding perinatal characteristics were present between both groups except for chorioamnionitis and preterm rupture of membranes which were more frequent in the UCM group. There was a significant reduction in the incidence of IVH in the UCM group as compared to the ICC group (UCM vs. ICC = 12 vs. 33%, p = 0.037; OR = 0.276 (95% CI 0.079-0.967; p = 0.033; NNT = 4.7) and a reduction in the number of transfusions (UCM vs. ICC = 56 vs. 30%, p = 0.035; OR = 0.348 (0.129-0.938; p = 0.033; NNT = 3.8). UCM was safe for mothers (similar decrease in maternal hemoglobin) and offspring.

CONCLUSION

UCM significantly reduced the incidence of IVH in preterm infants < 32 weeks' gestation without associated complications for mother or offspring.

Umbilical Cord Milking: A Review

This is a review of umbilical cord milking, a controversial technique where the umbilical cord is squeezed several times before it is clamped an cut. While not physiological or natural for newborns, the question lies as to whether it is useful in certain circumstances, namely the depressed newborn. Here we review the literature and discuss why it could be considered as an alternative for the current practice of delayed cord clamping.