Effect of Milking Maneuver in Preterm Infants: A Randomized Controlled Trial

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.

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..

Effects of spontaneous first breath on placental transfusion in term neonates born by cesarean section: A randomized controlled trial

BACKGROUND

The role of umbilical cord management in placental transfusion in cesarean section (CS) requires clarification. The spontaneous first breath may be more important than the timing of cord clamping for placental transfusion in neonates born by CS.

OBJECTIVE

This study aimed to evaluate the impact of cord clamping after the first spontaneous breath on placental transfusion in neonates born by CS.

METHODS

We recruited women with a live singleton pregnancy at ≥37.0 weeks of gestation admitted for CS. The interventions performed, such as physiologic-based cord clamping (PBCC), intact-umbilical cord milking (I-UCM), 30-s delay in cord clamping (30-s DCC), and 60-s delay in cord clamping (60-s DCC), were noted and placed in a sealed envelope. The sealed envelope was opened immediately before delivery to perform randomization.

RESULTS

A total of 123 infants were eligible for evaluation. Of these, 31, 30, 32, and 30 were assigned to the PBCC, I-UCM, 30-s DCC, and 60-s DCC groups, respectively. The mean hemoglobin (Hb) and mean hematocrit (Hct) were significantly higher in the 60-s DCC group than in the PBCC group (p = 0.028 and 0.019, respectively), but no difference was noted among the I-UCM, 30-s DCC, and PBCC groups at 36 h of age. Further, no significant differences were observed in the mean Hb and mean Hct among the I-UCM, 60-s DCC, and 30-s DCC groups. Peak total serum bilirubin (TSB) levels were higher in the 60-s DCC group than in the I-UCM and PBCC groups (p = 0.017), but there was no difference between the 60-s DCC and 30-s DCC groups during the first week of life. The phototherapy requirement was higher in 60-s DCC than in IUCM and 30-sDCC (p = 0.001).

CONCLUSIONS

Our findings demonstrated that PBCC, 30-s DCC, and I-UCM in neonates born by CS had no significant differences from each other on placental transfusion. The Hb and Hct in the neonates were higher after 60-s DCC than after PBCC.

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

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.

Umbilical Cord Milking vs Delayed Cord Clamping and Associations with In-Hospital Outcomes among Extremely Premature Infants

OBJECTIVE

To compare in-hospital outcomes after umbilical cord milking vs delayed cord clamping among infants <29 weeks of gestation.

STUDY DESIGN

Multicenter retrospective study of infants born <29 weeks of gestation from 2016 to 2018 without congenital anomalies who received active treatment at delivery and were exposed to umbilical cord milking or delayed cord clamping. The primary outcome was mortality or severe (grade III or IV) intraventricular hemorrhage (IVH) by 36 weeks of postmenstrual age (PMA). Secondary outcomes assessed at 36 weeks of PMA were mortality, severe IVH, any IVH or mortality, and a composite of mortality or major morbidity. Outcomes were assessed using multivariable regression, incorporating mortality risk factors identified a priori, confounders, and center. A prespecified, exploratory analysis evaluated severe IVH in 2 gestational age strata, 22-24^6/7 and 25-28^6/7 weeks.

RESULTS

Among 1834 infants, 23.6% were exposed to umbilical cord milking and 76.4% to delayed cord clamping. The primary outcome, mortality or severe IVH, occurred in 21.1% of infants: 28.3% exposed to umbilical cord milking and 19.1% exposed to delayed cord clamping, with an aOR that was similar between groups (aOR 1.45, 95% CI 0.93, 2.26). Infants exposed to umbilical cord milking had higher odds of severe IVH (19.8% umbilical cord milking vs 11.8% delayed cord clamping, aOR 1.70 95% CI 1.20, 2.43), as did the 25-28^6/7 week stratum (14.8% umbilical cord milking vs 7.4% delayed cord clamping, aOR 1.89 95% CI 1.22, 2.95). Other secondary outcomes were similar between groups.

CONCLUSIONS

This analysis of extremely preterm infants suggests that delayed cord clamping is the preferred practice for placental transfusion, as umbilical cord milking exposure was associated with an increase in the adverse outcome of severe IVH.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT00063063.

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.

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

CONTEXT

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

OBJECTIVE

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

DATA SOURCES

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

STUDY SELECTION

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

DATA EXTRACTION

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

RESULTS

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

LIMITATIONS

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

CONCLUSIONS

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

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.

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.