Effects of delayed cord clamping in intrauterine growth-restricted neonates: a randomized controlled trial

Deferred Cord Clamping in Twin Pregnancies Across Canada: A National Survey of Practices

OBJECTIVE

Guidelines recommending deferred cord clamping (DCC), delaying cord clamping for at least 30 seconds post-birth, have shown significant benefits in preterm singleton births. However, evidence supporting DCC in twins is scarce due to limited trial data, leading to practice variations. This study aims to assess current reported DCC practices for twin pregnancies in tertiary hospitals across Canada.

METHODS

A web-based survey was distributed to neonatologists and obstetrician investigators associated with the Canadian Neonatal and Preterm Birth Networks operating maternity and neonatal units.

RESULTS

The site response rate was 93% (28/30 sites), with 83% (25/30) for neonatologists and 56% (17/30) for obstetricians. The majority had a local protocol for twin pregnancies (obstetricians 13/17, neonatologists 21/25). While all centres practised DCC in dichorionic-diamniotic twins, a difference was noted for monochorionic-diamniotic twins, with 56% of neonatologists and 65% of obstetricians performing DCC. During cesarean delivery, most obstetricians (76.5%) placed the firstborn on the mother's thighs. Neonatologists varied in their practices, with 32% placing the baby on the mother's abdomen, 32% on the mother's thighs, and 28% holding the baby at the height of the perineum. Divergent opinions were observed regarding contraindications, including risks of postpartum hemorrhage and velamentous cord insertion.

CONCLUSIONS

DCC is reported to be practised in most twin deliveries among Canadian Neonatal and Preterm Birth Network centres. However, there are wide variations in practice, especially concerning the characteristics of the twins in which DCC is performed. Future research should investigate optimal cord clamping management in twins to standardize practices and maximize benefits.

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.

Effects of umbilical cord milking versus delayed cord clamping on systemic blood flow in intrauterine growth-restricted neonates: A randomized controlled trial

Recommendations for umbilical cord management in intrauterine growth-restricted (IUGR) neonates are lacking. The present randomized controlled trial compared hemodynamic effects of umbilical cord milking (UCM) with delayed cord clamping (DCC) in IUGR neonates > 28 weeks of gestation, not requiring resuscitation. One hundred seventy IUGR neonates were randomly allocated to intact UCM (4 times squeezing of 20 cm intact cord; n = 85) or DCC (cord clamping after 60 s; n = 85) immediately after delivery. The primary outcome variable was superior vena cava (SVC) blood flow at 24 ± 2 h. Secondary outcomes assessed were anterior cerebral artery (ACA) and superior mesenteric artery (SMA) blood flow indices, right ventricular output (RVO), regional cerebral oxygen saturation (CrSO2) and venous hematocrit at 24 ± 2 h, peak total serum bilirubin (TSB), incidences of in-hospital complications, need and duration of respiratory support, and hospital stay. SVC flow was significantly higher in UCM compared to DCC (111.95 ± 33.54 and 99.49 ± 31.96 mL/kg/min, in UCM and DCC groups, respectively; p < 0.05). RVO and ACA/SMA blood flow indices were comparable whereas CrSO2 was significantly higher in UCM group. Incidences of polycythemia and jaundice requiring phototherapy were similar despite significantly higher venous hematocrit and peak TSB in UCM group. The need for non-invasive respiratory support was significantly higher in UCM group though the need and duration of mechanical ventilation and other outcomes were comparable.

CONCLUSIONS

 UCM significantly increases SVC flow, venous hematocrit, and CrSO2 compared to DCC in IUGR neonates without any difference in other hemodynamic parameters and incidences of polycythemia and jaundice requiring phototherapy; however, the need for non-invasive respiratory support was higher with UCM.

TRIAL REGISTRATION

Clinical trial registry of India (CTRI/2021/03/031864).

WHAT IS KNOWN

• Umbilical cord milking (UCM) increases superior vena cava blood flow (SVC flow) and hematocrit without increasing the risk of symptomatic polycythemia and jaundice requiring phototherapy in preterm neonates compared to delayed cord clamping (DCC). • An association between UCM and intraventricular hemorrhage in preterm neonates < 28 weeks of gestation is still being investigated.

WHAT IS NEW

• Placental transfusion by UCM compared to DCC increases SVC flow, regional cerebral oxygenation, and hematocrit without increasing the incidence of symptomatic polycythemia and jaundice requiring phototherapy in intrauterine growth-restricted neonates. • UCM also increases the need for non-invasive respiratory support compared to DCC.

Effects of delayed cord clamping at different time intervals in late preterm and term neonates: a randomized controlled trial

Delayed cord clamping (DCC) at delivery has well-recognized benefits; however, current scientific guidelines lack uniformity in its definition. This parallel-group, three-arm assessor-blinded randomized controlled trial compared the effects of three different timings of DCC at 30, 60, and 120 s on venous hematocrit and serum ferritin levels in late preterm and term neonates not requiring resuscitation. Eligible newborns (n = 204) were randomized to DCC 30 (n = 65), DCC 60 (n = 70), and DCC 120 (n = 69) groups immediately after delivery. The primary outcome variable was venous hematocrit at 24 ± 2 h. Secondary outcome variables were respiratory support, axillary temperature, vital parameters, incidences of polycythemia, neonatal hyperbilirubinemia (NNH), need and duration of phototherapy, and postpartum hemorrhage (PPH). Additionally, serum ferritin levels, the incidence of iron deficiency, exclusive breastfeeding (EBF) rate, and anthropometric parameters were assessed during post-discharge follow-up at 12 ± 2 weeks. Over one-third of the included mothers were anemic. DCC 120 was associated with a significant increase in the mean hematocrit by 2%, incidence of polycythemia, and duration of phototherapy, compared to DCC30 and DCC60; though the incidence of NNH and need for phototherapy was similar. No other serious neonatal or maternal adverse events including PPH were observed. No significant difference was documented in serum ferritin, incidences of iron deficiency, and growth parameters at 3 months even in the presence of a high EBF rate.   Conclusion: The standard recommendation of DCC at 30-60 s may be considered a safe and effective intervention in the busy settings of low-middle-income countries with a high prevalence of maternal anemia.   Trial registration: Clinical trial registry of India (CTRI/2021/10/037070). What is Known: • The benefits of delayed cord clamping (DCC) makes it an increasingly well-accepted practice in the delivery room. • However, uncertainty continues regarding the optimal timing of clamping; this may be of concern both in the neonate and the mother. What is New: • DCC at 120 s led to higher hematocrit, polycythemia and longer duration of phototherapy, without any difference in serum ferritin, and incidence of iron deficiency. • DCC at 30-60 s may be considered a safe and effective intervention in LMICs.

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.

Toward greater nuance in delayed cord clamping

PURPOSE OF REVIEW

For over a decade, the International Liaison Committee on Resuscitation has recommended delayed cord clamping (DCC), but implementation has been variable due to lack of consensus on details of technique and concerns for risks in certain patient populations. This review summarizes recent literature on the benefits and risks of DCC in term and preterm infants and examines alternative approaches such as physiologic-based cord clamping or intact cord resuscitation (ICR) and umbilical cord milking (UCM).

RECENT FINDINGS

DCC improves hemoglobin/hematocrit among term infants and may promote improved neurodevelopment. In preterms, DCC improves survival compared to early cord clamping; however, UCM has been associated with severe intraventricular hemorrhage in extremely preterm infants. Infants of COVID-19 positive mothers, growth-restricted babies, multiples, and some infants with cardiopulmonary anomalies can also benefit from DCC. Large randomized trials of ICR will clarify safety and benefits in nonvigorous neonates. These have the potential to dramatically change the sequence of events during neonatal resuscitation.

SUMMARY

Umbilical cord management has moved beyond simple time-based comparisons to nuances of technique and application in vulnerable sub-populations. Ongoing research highlights the importance of an individualized approach that recognizes the physiologic equilibrium when ventilation is established before cord clamping.

Delayed cord clamping in small for gestational age preterm infants

BACKGROUND

Infants with restricted growth for age are frequently exposed to insufficient placental circulation and are more likely to develop postnatal complications. Delayed cord clamping at birth for these infants requires further exploration.

OBJECTIVE

This study aimed to compare the short-term neonatal outcomes of delayed cord clamping with that of early cord clamping in small for gestational age preterm infants and to explore whether the effects of delayed cord clamping in small for gestational age preterm infants are different from that in non-small for gestational age preterm infants.

STUDY DESIGN

We conducted a national retrospective cohort study, including infants born at <33 weeks' gestation and admitted to the Canadian Neonatal Network units between January 2015 and December 2017. Small for gestational age infants (birthweight of <10th percentile for gestational age and sex) who received delayed cord clamping ≥30 seconds were compared with those who received early cord clamping. In addition, non-small for gestational age infants who received delayed cord clamping were compared with those who received early cord clamping. The main study outcomes included composite outcome of mortality or major morbidity, neonatal morbidity rate, mortality rate, peak serum bilirubin, and number of blood transfusions. Multivariable logistic and linear regression models with a generalized estimation equation approach were used to account for the clustering of infants within centers.

RESULTS

Overall, 9722 infants met the inclusion criteria. Of those infants, 1027 (10.6%) were small for gestational age. The median (interquartile range) gestational age was 31 weeks (range, 28-32 weeks). After adjusting for potential confounders, delayed cord clamping in small for gestational age infants was associated with a reduction in the composite outcome of mortality or major morbidity (adjusted odds ratio, 0.60; 95% confidence interval, 0.42-0.86) compared with early cord clamping. There was no difference between the 2 groups in peak serum bilirubin. Many associated benefits of delayed cord clamping in small for gestational age infants were similar to those in non-small for gestational age infants.

CONCLUSION

Delayed cord clamping in small for gestational age preterm infants was associated with decreased odds of mortality or major morbidity. Many of the benefits of delayed cord clamping in the small for gestational age preterm infants were similar to those identified in the non-small for gestational age preterm infants.

Management of Placental Transfusion to Neonates After Delivery

This review summarizes high-quality evidence supporting delayed umbilical cord clamping to promote placental transfusion to preterm and term neonates. In preterm neonates, delayed cord clamping may decrease mortality and the need for blood transfusions. Although robust data are lacking to guide cord management strategies in many clinical scenarios, emerging literature is reviewed on numerous topics including delivery mode, twin gestations, maternal comorbidities (eg, gestational diabetes, red blood cell alloimmunization, human immunodeficiency virus [HIV] infection, and severe acute respiratory syndrome coronavirus 2 [SARS-CoV-2] infection) and neonatal complications (eg, fetal growth restriction, congenital heart disease, and the depressed neonate). Umbilical cord milking is an alternate method of rapid placental transfusion, but has been associated with severe intraventricular hemorrhage in extremely preterm neonates. Data on long-term outcomes are discussed, as well as potential contraindications to delayed cord clamping. Overall, delayed cord clamping offers potential benefits to the estimated 140 million neonates born globally every year, emphasizing the importance of this simple and no-cost strategy.

Impact of Umbilical Cord Milking on Hematological Parameters in Preterm Neonates With Placental Insufficiency

BACKGROUND

Data is still lacking about the expediency of umbilical cord milking (UCM) in preterm neonates born to mothers with placental insufficiency (PI).

OBJECTIVE

To study the effect of UCM in preterm neonates who had ante-natal evidence of placental insufficiency on peripheral blood cluster of differentiation 34 (CD34) percentage, hematological indices, and clinical outcomes.

METHODS

Preterm neonates, <34 weeks' gestation, born to mothers with evidence of placental insufficiency that underwent UCM (PI+UCM group) were compared with historical controls whose umbilical stumps were immediately clamped [PI+ICC (immediate cord clamping) group] in a case-control study. Peripheral blood CD34 percentage as a measure of hematopoietic stem cell transfusion was the primary outcome. Early and late-onset anemia; polycythemia; frequency of packed red blood cells (PRBCs) transfusion during NICU stay; peak total serum bilirubin (TSB); incidence of phototherapy, admission rectal temperature; first 24 h hypothermia and hypoglycemia; episodes of hypotension and need for volume expander boluses and inotropic support during the first 24 h of age; duration of oxygen therapy; bronchopulmonary dysplasia (BPD); severe intra-ventricular hemorrhage (IVH); necrotizing enterocolitis (NEC); culture-proven late-onset sepsis; length of hospital stay; and in-hospital mortality were secondary outcomes.

RESULTS

In preterm infants with placental insufficiency, umbilical cord milking was associated with greater peripheral blood CD34 percentage, hemoglobin levels initially and at postnatal age of 2 months, alongside significantly shorter duration of oxygen therapy compared with ICC group. Frequency of packed RBCs transfusion during hospital stay was comparable. Neonates in UCM group had a greater peak TSB level during admission with significantly higher need for phototherapy initiation compared with ICC. Logistic regression, adjusted for gestational age, revealed that UCM resulted in greater CD34 percentage, higher initial hemoglobin level, higher peak serum bilirubin, significant increase of phototherapy initiation, and higher hemoglobin level at 2 months.

CONCLUSIONS

UCM in preterm neonates born to mothers with placental insufficiency was feasible and resulted in greater CD34 percentage, higher initial hemoglobin level, higher peak serum bilirubin, significant increase of phototherapy initiation, and higher hemoglobin level at 2 months.