Effect of Delayed Cord Clamping on Umbilical Blood Gas Values in Term Newborns: A Systematic Review

Arterial blood gases in newborn infants: Early extraction without prior clamping versus extraction after delayed clamping

OBJECTIVES

To compare the postpartum arterial blood gas parameters recorded early before cord clamping and after delayed cord clamping (DCC). To explore adverse effects and complications of the cord blood gas collection technique without clamping.

DESIGN

Randomised controlled trial.

SETTING

Birthing room of La Ribera University Hospital (Valencia, Spain).

PARTICIPANTS

122 full-term infants born between February 2020 and January 2021. Two groups were established: the experimental group (early sampling prior to clamping and sampling again after DCC) and the non-experimental group (sampling only after DCC).

MEASUREMENTS AND FINDINGS

The comparison of arterial blood gas parameters was made using the Student t-test, while the Fisher's exact test was used to compare the proportion of the adverse effects recorded. The pH and base excess values in the experimental group were significantly greater when the sampling was performed without prior clamping. No statistically significant differences were observed in relation to pCO₂ or the appearance of adverse effects between the two groups. No complications were recorded.

KEY CONCLUSIONS AND IMPLICATIONS FOR PRACTICE

The pH and base excess values were higher when the arterial blood gas measurements were made prior to performing the umbilical cord clamping than when the sampling was performed after the DCC. Arterial blood gas sampling without prior clamping was found to be safe, since no complications or increased adverse effects were observed. The use of this technique is therefore advised in normal births of full-term infants.

GRADE Use in Evidence Syntheses Published in High-Impact-Factor Gynecology and Obstetrics Journals: A Methodological Survey

Objective: To identify and describe the certainty of evidence of gynecology and obstetrics systematic reviews (SRs) using the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) approach. Method: Database searches of SRs using GRADE, published between 1 January 2016 to 31 December 2020, in the 10 "gynecology and obstetrics" journals with the highest impact factor, according to the Journal Citation Report 2019. Selected studies included those SRs using the GRADE approach, used to determine the certainty of evidence. Results: Out of 952 SRs, ninety-six SRs of randomized control trials (RCTs) and/or nonrandomized studies (NRSs) used GRADE. Sixty-seven SRs (7.04%) rated the certainty of evidence for specific outcomes. In total, we identified 946 certainty of evidence outcome ratings (n = 614 RCT ratings), ranging from very-low (42.28%) to low (28.44%), moderate (17.65%), and high (11.63%). High and very low certainty of evidence ratings accounted for 2.16% and 71.60% in the SRs of NRSs, respectively, compared with 16.78% and 26.55% in the SRs of RCTs. In the SRs of RCTs and NRSs, certainty of evidence was mainly downgraded due to imprecision and bias risks. Conclusions: More attention needs to be paid to strengthening GRADE acceptance and building knowledge of GRADE methods in gynecology and obstetrics evidence synthesis.

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

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

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

Background

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

Methods

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

Results

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

Conclusion

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

What does the evidence tell us? Revisiting optimal cord management at the time of birth

A newborn who receives a placental transfusion at birth from delayed cord clamping (DCC) obtains about 30% more blood volume than those with immediate cord clamping (ICC). Benefits for term neonates include higher hemoglobin levels, less iron deficiency in infancy, improved myelination out to 12 months, and better motor and social development at 4 years of age especially in boys. For preterm infants, benefits include less intraventricular hemorrhage, fewer gastrointestinal issues, lower transfusion requirements, and less mortality in the neonatal intensive care unit by 30%. Ventilation before clamping the umbilical cord can reduce large swings in cardiovascular function and help to stabilize the neonate. Hypovolemia, often associated with nuchal cord or shoulder dystocia, may lead to an inflammatory cascade and subsequent ischemic injury. A sudden unexpected neonatal asystole at birth may occur from severe hypovolemia. The restoration of blood volume is an important action to protect the hearts and brains of neonates. Currently, protocols for resuscitation call for ICC. However, receiving an adequate blood volume via placental transfusion may be protective for distressed neonates as it prevents hypovolemia and supports optimal perfusion to all organs. Bringing the resuscitation to the mother's bedside is a novel concept and supports an intact umbilical cord. When one cannot wait, cord milking several times can be done quickly within the resuscitation guidelines. Cord blood gases can be collected with optimal cord management.   Conclusion: Adopting a policy for resuscitation with an intact cord in a hospital setting takes a coordinated effort and requires teamwork by obstetrics, pediatrics, midwifery, and nursing.

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.

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.

Effects of Umbilical Cord Management Strategies on Stem Cell Transfusion, Delivery Room Adaptation, and Cerebral Oxygenation in Term and Late Preterm Infants

BACKGROUND

The umbilical cord blood contains a high concentration of stem cells. There is not any published study evaluating the amount of stem cells that have the potential to be transferred to the infant through placental transfusion methods as delayed cord clamping (DCC) and umbilical cord milking (UCM). The aim of this study is to measure the concentrations of endothelial progenitor cell (EPC) and CD34+ hematopoietic stem cell (HSC) in the placental residual blood volume (PRBV), and evaluate the delivery room adaptation and cerebral oxygenation of these infants.

METHODS

Infants with ≥36 gestational weeks were randomized to receive DCC (120 s), UCM, or immediate cord clamping (ICC). EPC and CD34+ HSC were measured by flow cytometry from the cord blood. PRBV was collected in the setup. The cord blood gas analysis and complete blood count were performed. The heart rate (HR), oxygen saturation (SpO2), and cerebral regional oxygen saturation (crSO2) were recorded.

RESULTS

A total of 103 infants were evaluated. The amount of PRBV (in ml and ml/kg) was higher in the ICC group (p < 0.001). The number of EPCs in the PRBV content (both ml and ml/kg) were the highest in the ICC group (p = 0.002 and p = 0.001, respectively). The number of CD34+ HSCs in PRBV content (ml and ml/kg) was similar in all groups, but nonsignificantly higher in the ICC group. The APGAR scores at the first and fifth min were lower in the ICC group (p < 0.05). The mean crSO2 values were higher at the 3rd and 10th min in the DCC group (p = 0.042 and p = 0.045, respectively). cFOE values were higher at the 3rd and 10th min in the ICC group (p = 0.011 and p < 0.001, respectively).

CONCLUSION

This study showed that placental transfusion methods, such as DCC and UCM, provide both higher blood volume, more stem cells transfer to the infant, and better cerebral oxygenation in the first minutes of life, whereas many lineages of stem cells is lost to the placenta by ICC with higher residual blood volume. These cord management methods rather than ICC do not require any cost or technology, and may be a preemptive therapeutic source for diseases of the neonatal period.

Does physiological-based cord clamping improve cerebral tissue oxygenation and perfusion in healthy term neonates? - A randomized controlled trial

OBJECTIVES

To evaluate cerebral tissue oxygenation index (cTOI) during neonatal transition in a group of healthy full-term neonates receiving either a physiological-based approach of deferred cord clamping (CC) after the onset of stable regular breathing (PBCC group) or a standard approach of time-based CC < 1 min (control group). Secondary aim was to evaluate changes in cerebral blood volume (ΔCBV), peripheral arterial oxygen saturation (SpO2) and heart rate (HR) in those neonates.

MATERIALS AND METHODS

We conducted a randomized controlled trial (clinicaltrials.gov: NCT02763436) including vaginally delivered healthy full-term neonates. Continuous measurements of cTOI and ΔCBV using near-infrared spectroscopy, and of SpO2 and HR using pulse oximetry were performed within the first 15 min after birth. Data of each minute of the PBCC group were compared to those of the control group.

RESULTS

A total of 71 full-term neonates (PBCC: n = 35, control: n = 36) with a mean (SD) gestational age of 40.0 (1.0) weeks and a birth weight of 3,479 (424) grams were included. Median (IQR) time of CC was 275 (197-345) seconds and 58 (35-86) seconds in the PBCC and control group, respectively (p < 0.001). There were no significant differences between the two groups regarding cTOI (p = 0.319), ΔCBV (p = 0.814), SpO2 (p = 0.322) and HR (p = 0.878) during the first 15 min after birth.

CONCLUSION

There were no significant differences in the course of cTOI as well as ΔCBV, SpO2 and HR during the first 15 min after birth in a group of healthy full-term neonates, who received either deferred CC after the onset of stable regular breathing or standard CC < 1 min. Thus, deferring CC ≥ 1 min following a physiological-based approach offers no benefits regarding cerebral tissue oxygenation and perfusion after uncomplicated vaginal delivery compared to a time-based CC approach.

Developments in pediatrics in 2020: choices in allergy, autoinflammatory disorders, critical care, endocrinology, genetics, infectious diseases, microbiota, neonatology, neurology, nutrition, ortopedics, respiratory tract illnesses and rheumatology

In this article, we describe the advances in the field of pediatrics that have been published in the Italian Journal of Pediatrics in 2020. We report progresses in understanding allergy, autoinflammatory disorders, critical care, endocrinology, genetics, infectious diseases, microbiota, neonatology, neurology, nutrition, orthopedics, respiratory tract illnesses, rheumatology in childhood.

Cord Management of the Term Newborn

Keeping the umbilical cord intact after delivery facilitates transition from fetal to neonatal circulation and allows a placental transfusion of a considerable amount of blood. A delay of at least 3 minutes improves neurodevelopmental outcomes in term infants. Although regarded as common sense and practiced by many midwives, implementation of delayed cord clamping into practice has been unduly slow, partly because of beliefs regarding theoretic risks of jaundice and lack of understanding regarding the long-term benefits. This article provides arguments for delaying cord clamping for a minimum of 3 minutes.

The effect of clamped and unclamped umbilical cord samples on blood gas analysis

Purpose

Delayed cord clamping for at least 60 s is recommended to improve neonatal outcomes. The aim of this study is to evaluate whether there are differences in cord BGA between samples collected after double clamping the cord or without clamping the cord, when blood collection occurs within 60 s from birth in both groups.

Methods

A cross-sectional study was carried out, collecting data from 6884 high-risk women who were divided into two groups based on the method of cord sampling (clamped vs unclamped).

Results

There were significant decrease in pH and BE values into unclamped group compared with the clamped group. This difference remained significant when considering pathological blood gas analysis parameters, with a higher percentage of pathological pH or BE values in the unclamped group.

Conclusion

Samples from the unclamped cord alter the acid–base parameters compared to collection from the clamped cord; however, this difference does not appear to be of clinical relevance. Findings could be due to the large sample size, which allowed to achieve a high power and to investigate very small numerical changes between groups, leading to a statistically significant difference in pH and BE between samples even when we could not appreciate any clinical relevant difference of pH or BE between groups. When blood gas analysis is indicated, the priority should be given to the timing of blood collection to allow reliable results, to assess newborns status at birth and intervene when needed.

Delayed cord clamping in healthy term infants: More harm or good?

It is recommended to delay cord clamping in healthy term infants for at least 60- and 180-s in high- and limited-resource environments, as delayed cord clamping lowers the incidence of anemia and iron deficiency and improves neurodevelopment. There are improvements in hemodynamic parameters such as peripheral arterial oxygen saturation, heart rate, cardiac output, and cerebral oxygenation. Historically, delayed cord clamping caused a higher rate of hyperbilirubinemia and phototherapy, but more recent evidence suggests this may no longer be the case. In limited-resource environments delayed cord clamping may reduce anemia and iron deficiency potentially improving neurodevelopmental outcomes. The use of delayed cord clamping in newborn infants with intrauterine growth restriction or monochorionic twins is limited and further evidence is needed before it can be formally recommended.

Analysis of Factors Associated With Variability and Acidosis of the Umbilical Artery pH at Birth

Background: Perinatal asphyxia is a significant contributing factor for neonatal morbidity and mortality. The aim of this study was to investigate the clinical factors associated with umbilical artery pH variability and fetal acidosis at birth. Methods: This is a single center cross-sectional study in a public regional hospital in southeastern Spain from January to December 2019. The reference population was 1.655 newborns, final sample of 312 experimental units with validated values of umbilical cord blood pH. Results: Factors such as gestational age at term ( X ¯ at - term : 7.26 ± 0.08- X ¯ no -_at-term: 7.31 ± 0.05, p: 0.00), primiparity ( X ¯ primiparity : 7.24 ± 0.078- X ¯ multiparity : 7.27 ± 0.08, p: 0.01), induced labor ( X ¯ induced : 7.24 ± 0.07- X ¯ spontaneous : 7.26 ± 0.081, p: 0.02), vaginal delivery ( X ¯ vaginal :7.25 ± 0.08- X ¯ cesarean :7.27 ± 0.07, p: 0.01), and prolonged dilation duration ( X ¯ AboveAverage : 7.22 ± 0.07- X ¯ BelowAverage : 7.27 ± 0.08, p: 0.00), expulsion duration ( X ¯ AboveAverage : 7.23 ± 0.07- X ¯ BelowAverage : 7.26 ± 0.08, p: 0.01), and total labor duration ( X ¯ AboveAverage : 7.23 ± 0.07- X ¯ BelowAverage : 7.27 ± 0.08, p: 0.00) are associated with a decrease in umbilical artery pH at birth. However, only three factors are associated with acidosis pH (<7.20) of the umbilical artery at birth: the induction of labor [OR: 1.74 (95% CI: 0.98-3.10); p: 0.04], vaginal delivery [OR: 2.09 (95% CI: 0.95-4.61); p: 0.04], and total duration of labor [OR: 2.06 (95% CI: 1.18-3.57); p: 0.01]. Conclusions: Although several factors may affect the variability of umbilical artery pH at birth by decreasing their mean values (gestational age, primiparity, induced labor, vaginal delivery and prolonged: dilation duration, expulsion duration and total labor duration), only induction of labor, vaginal delivery and total duration of labor are associated with an acidosis (<7.20) of same.