The effect of early versus late cord clamping on signs of respiratory distress

Monitoring of the Healthy Neonatal Transition Period with Serial Lung Ultrasound

Ultrasound has been used to observe lung aeration and fluid clearance during the neonatal transition period, but there is no consensus regarding the optimal timing of lung ultrasound. We aimed to monitor the trend of the serial lung ultrasound score (LUS) and extended LUS (eLUS) throughout the neonatal transition period (≤1, 2, 4, 8, 24, and 48 h after birth), assess any correlation to the clinical presentation (using the Silverman Andersen Respiratory Severity Score (RSS)), and determine the optimal time of the ultrasound. We found both LUS and eLUS decreased significantly after 2 h of life and had similar statistical differences among the serial time points. Although both scores had a positive, moderate correlation to the RSS overall (Pearson correlation 0.499 [p < 0.001] between LUS and RSS, 0.504 [p < 0.001] between eLUS and RSS), the correlation was poor within 1 h of life (Pearson correlation 0.15 [p = 0.389] between LUS and RSS, 0.099 [p = 0.573] between eLUS and RSS). For better clinical correlation, the first lung ultrasound for the neonate may be performed at 2 h of life. Further research is warranted to explore the clinical value and limitations of earlier (≤1 h of life) lung ultrasound examinations.

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.

Delayed Cord Clamping in Infants of Diabetic Mothers: Laboratory and Clinical Outcomes

The aim of this study was to compare the effects of delayed cord clamping (DCC) and early cord clamping (ECC) on venous hematocrit (htc) and clinical outcomes in infants of diabetic mothers (IDMs). This prospective randomized study included 157 term IDMs. The umbilical cords of these infants were clamped at least 60 seconds in group I (DCC group, n = 79) and as soon as possible after birth in group II (ECC group, n = 78). The two groups were compared regarding neonatal venous htc levels, hypoglycemia rates, jaundice requiring phototherapy, respiratory distress, and admission to the neonatal intensive care unit (NICU). Hematocrit levels were significantly higher in the DCC group, both at 6 and 24 hours postnatally (p = 0.039 and 0.01), respectively. Polycythemia frequency was higher in DCC than the ECC group, but no patient in either group needed partial exchange transfusion (PET). Rates of jaundice were significantly higher in the DCC group (p = 0.028), but there was no significant difference between the two groups regarding jaundice requiring phototherapy (p = 0.681). There were no differences between the groups regarding hypoglycemia rates, need for glucose infusion, or respiratory distress. The incidence of admission to NICU was lower in the DCC group (p = 0.005). Early clamping was a significant predictor for increased risk of NICU admission. DCC increased polycythemia and jaundice rates but did not increase the need for PET or phototherapy. Also, DCC reduced the severity of respiratory distress and the subsequent need for NICU admission.

Umbilical Cord Management at Term and Late Preterm Birth: A Meta-analysis

CONTEXT

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

OBJECTIVE

To assess effects of umbilical cord management strategies (clamping timing and cord milking) in infants ≥34 weeks' gestational age.

DATA SOURCES

Cochrane Central Register of Controlled Trials, Medline, PubMed, Embase, Cumulative Index to Nursing and Allied Health Literature, and trial registries searched July 2019.

STUDY SELECTION

Two authors independently assessed eligibility of randomized controlled trials.

DATA EXTRACTION

Two authors independently extracted data and assessed evidence certainty (Grading of Recommendations Assessment, Development and Evaluations).

RESULTS

We identified 46 studies (9159 women and their infants) investigating 7 comparisons. Compared with early cord clamping (ECC) <30 seconds, delayed cord clamping (DCC) ≥30 seconds (33 studies), intact-cord milking (1 study), and cut-cord milking (2 studies) probably improve hematologic measures but may not affect survival without neurodisability, anemia in early infancy, or maternal postpartum hemorrhage. No differences in major neonatal morbidities are seen in studies comparing methods of optimizing placental transfusion (DCC versus cut-cord milking [3 studies], longer delays in clamping [7 studies], or physiologic parameters [3 studies]). Strategies that promote increased placental transfusion may be associated with greater phototherapy use. Evidence for all outcomes was low or very low certainty.

LIMITATIONS

Incompleteness and low certainty of findings limit applicability.

CONCLUSIONS

Compared with ECC, DCC or cord milking increases hemoglobin and hematocrit immediately after birth in infants ≥34 weeks' gestational age. The uncertain effects of DCC and cord milking compared with ECC on major morbidities limit usefulness of available evidence for policy and practice.

Evaluation of the Effects of Delayed Cord Clamping in Infants of Diabetic Mothers

OBJECTIVE

This study aimed to investigate the effect of delayed cord clamping (DCC) in infants of diabetic mothers.

STUDY DESIGN

Women who had diabetes throughout their pregnancy and gave birth at 37 weeks of gestation or later were included in the study along with their babies. Early cord clamping was performed as soon as possible after birth, while DCC was performed by clamping 60 second after birth. The two groups were compared in terms of venous hematocrit (htc) levels and rates of hypoglycemia, jaundice requiring phototherapy, and respiratory distress.

RESULTS

Venous htc levels at postnatal 6 and 24 hours were significantly higher in the DCC group (p = 0.0001). Polycythemia rates were higher in the DCC group at both 6 and 24 hours, but partial exchange transfusion (PET) was not needed in either group. There were no differences between the groups with regard to the rates of hypoglycemia or jaundice requiring phototherapy. Rate of admission to the neonatal intensive care unit (NICU) was lower in the DCC group.

CONCLUSION

Although DCC increased the rate of polycythemia, it did not result in PET requirement. Moreover, DCC reduced the severity of respiratory distress and the rate of admission to NICU due to respiratory distress.

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.

Delayed cord clamping in term large-for-gestational age infants: A prospective randomised study

AIM

To compare the post-natal effects of delayed cord clamping (DCC) and early cord clamping (ECC) in term large-for-gestational age (LGA) infants.

METHODS

This prospective randomised study included 51 term LGA infants. The umbilical cords of these infants were clamped at 15 s in group 1 (ECC group (n = 26)) and at 60 s in group 2 (DCC group (n = 25)). Data for Apgar scores, cord blood, pH and lactate values, second haematocrit, 24th bilirubin levels, duration of hospital stay and admission to the neonatal intensive care unit (NICU) were recorded.

RESULTS

The demographic characteristics of the infants in the study group were not significantly different. No statistically significant difference was observed in the post-natal haematocrit and bilirubin levels between the groups. Six infants (group 1, n = 3; group 2, n = 3) were diagnosed with polycythaemia (P = 0.79); however, these infants remained asymptomatic, and no treatment was required. One infant in each group developed hyperbilirubinemia, which required phototherapy (P = 1.00). The infant with hyperbilirubinemia in the DCC group presented with asymptomatic polycythaemia. Three neonates in the DCC group required admission to the NICU for transient tachypnoea.

CONCLUSIONS

No significant increase in the rate of post-natal complications of DCC in term LGA infants was observed in the study. However, before recommending DCC on a routine basis, studies with a larger sample size and long-term follow-up are required to elucidate the risks and benefits of DCC in this group of infants.

Effect of timing of umbilical cord clamping of term infants on maternal and neonatal outcomes

BACKGROUND

Policies for timing of cord clamping vary, with early cord clamping generally carried out in the first 60 seconds after birth, whereas later cord clamping usually involves clamping the umbilical cord more than one minute after the birth or when cord pulsation has ceased. The benefits and potential harms of each policy are debated.

OBJECTIVES

To determine the effects of early cord clamping compared with late cord clamping after birth on maternal and neonatal outcomes

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (13 February 2013).

SELECTION CRITERIA

Randomised controlled trials comparing early and late cord clamping.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trial eligibility and quality and extracted data.

MAIN RESULTS

We included 15 trials involving a total of 3911 women and infant pairs. We judged the trials to have an overall moderate risk of bias. Maternal outcomes: No studies in this review reported on maternal death or on severe maternal morbidity. There were no significant differences between early versus late cord clamping groups for the primary outcome of severe postpartum haemorrhage (risk ratio (RR) 1.04, 95% confidence interval (CI) 0.65 to 1.65; five trials with data for 2066 women with a late clamping event rate (LCER) of ~3.5%, I(2) 0%) or for postpartum haemorrhage of 500 mL or more (RR 1.17 95% CI 0.94 to 1.44; five trials, 2260 women with a LCER of ~12%, I(2) 0%). There were no significant differences between subgroups depending on the use of uterotonic drugs. Mean blood loss was reported in only two trials with data for 1345 women, with no significant differences seen between groups; or for maternal haemoglobin values (mean difference (MD) -0.12 g/dL; 95% CI -0.30 to 0.06, I(2) 0%) at 24 to 72 hours after the birth in three trials. Neonatal outcomes: There were no significant differences between early and late clamping for the primary outcome of neonatal mortality (RR 0.37, 95% CI 0.04 to 3.41, two trials, 381 infants with a LCER of ~1%), or for most other neonatal morbidity outcomes, such as Apgar score less than seven at five minutes or admission to the special care nursery or neonatal intensive care unit. Mean birthweight was significantly higher in the late, compared with early, cord clamping (101 g increase 95% CI 45 to 157, random-effects model, 12 trials, 3139 infants, I(2) 62%). Fewer infants in the early cord clamping group required phototherapy for jaundice than in the late cord clamping group (RR 0.62, 95% CI 0.41 to 0.96, data from seven trials, 2324 infants with a LCER of 4.36%, I(2) 0%). Haemoglobin concentration in infants at 24 to 48 hours was significantly lower in the early cord clamping group (MD -1.49 g/dL, 95% CI -1.78 to -1.21; 884 infants, I(2) 59%). This difference in haemoglobin concentration was not seen at subsequent assessments. However, improvement in iron stores appeared to persist, with infants in the early cord clamping over twice as likely to be iron deficient at three to six months compared with infants whose cord clamping was delayed (RR 2.65 95% CI 1.04 to 6.73, five trials, 1152 infants, I(2) 82%). In the only trial to report longer-term neurodevelopmental outcomes so far, no overall differences between early and late clamping were seen for Ages and Stages Questionnaire scores.

AUTHORS' CONCLUSIONS

A more liberal approach to delaying clamping of the umbilical cord in healthy term infants appears to be warranted, particularly in light of growing evidence that delayed cord clamping increases early haemoglobin concentrations and iron stores in infants. Delayed cord clamping is likely to be beneficial as long as access to treatment for jaundice requiring phototherapy is available.

Effect of timing of umbilical cord clamping and other strategies to influence placental transfusion at preterm birth on maternal and infant outcomes

BACKGROUND

Optimal timing for clamping the umbilical cord at preterm birth is unclear. Early clamping allows for immediate transfer of the infant to the neonatologist. Delaying clamping allows blood flow between the placenta, the umbilical cord and the baby to continue. The blood which transfers to the baby between birth and cord clamping is called placental transfusion. Placental transfusion may improve circulating volume at birth, which may in turn improve outcome for preterm infants.

OBJECTIVES

To assess the short- and long-term effects of early rather than delaying clamping or milking of the umbilical cord for infants born at less than 37 completed weeks' gestation, and their mothers.

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth Group Trials Register (31 May 2011). We updated this search on 26 June 2012 and added the results to the awaiting classification section.

SELECTION CRITERIA

Randomised controlled trials comparing early with delayed clamping of the umbilical cord and other strategies to influence placental transfusion for births before 37 completed weeks' gestation.

DATA COLLECTION AND ANALYSIS

Three review authors assessed eligibility and trial quality.

MAIN RESULTS

Fifteen studies (738 infants) were eligible for inclusion. Participants were between 24 and 36 weeks' gestation at birth. The maximum delay in cord clamping was 180 seconds. Delaying cord clamping was associated with fewer infants requiring transfusions for anaemia (seven trials, 392 infants; risk ratio (RR) 0.61, 95% confidence interval (CI) 0.46 to 0.81), less intraventricular haemorrhage (ultrasound diagnosis all grades) 10 trials, 539 infants (RR 0.59, 95% CI 0.41 to 0.85) and lower risk for necrotising enterocolitis (five trials, 241 infants, RR 0.62, 95% CI 0.43 to 0.90) compared with immediate clamping. However, the peak bilirubin concentration was higher for infants allocated to delayed cord clamping compared with immediate clamping (seven trials, 320 infants, mean difference 15.01 mmol/L, 95% CI 5.62 to 24.40). For most other outcomes (including the primary outcomes infant death, severe (grade three to four) intraventricular haemorrhage and periventricular leukomalacia) there were no clear differences identified between groups; but for many there was incomplete reporting and wide CIs. Outcome after discharge from hospital was reported for one small study; there were no significant differences between the groups in mean Bayley II scores at age seven months (corrected for gestation at birth (58 children)).No studies reported outcomes for the women.

AUTHORS' CONCLUSIONS

Providing additional placental blood to the preterm baby by either delaying cord clamping for 30 to 120 seconds, rather than early clamping, seems to be associated with less need for transfusion, better circulatory stability, less intraventricular haemorrhage (all grades) and lower risk for necrotising enterocolitis. However, there were insufficient data for reliable conclusions about the comparative effects on any of the primary outcomes for this review.

Timing of umbilical cord clamping: new thoughts on an old discussion

The optimal time to clamp the umbilical cord in preterm and full-term neonates after birth continues to be a matter of debate. A review of randomised controlled trials comparing the effects of early versus late cord clamping on maternal and infant outcomes was performed to assess data in favor of immediate or delayed clamping. Although there is no conclusive evidence, delayed cord clamping seems to be beneficial in preterm and full-term neonates without compromising the initial postpartum adaptation phase or affecting the mother in the short term. However, further randomised clinical studies are needed to confirm the benefits of delayed cord clamping.

Effect of timing of umbilical cord clamping of term infants on maternal and neonatal outcomes

BACKGROUND

Policies for timing of cord clamping vary, with early cord clamping generally carried out in the first 60 seconds after birth, whereas later cord clamping usually involves clamping the umbilical cord greater than one minute after the birth or when cord pulsation has ceased.

OBJECTIVES

To determine the effects of different policies of timing of cord clamping at delivery of the placenta on maternal and neonatal outcomes.

SEARCH STRATEGY

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (December 2007).

SELECTION CRITERIA

Randomised controlled trials comparing early and late cord clamping.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trial eligibility and quality and extracted data.

MAIN RESULTS

We included 11 trials of 2989 mothers and their babies. No significant differences between early and late cord clamping were seen for postpartum haemorrhage or severe postpartum haemorrhage in any of the five trials (2236 women) which measured this outcome (relative risk (RR) for postpartum haemorrhage 500 mls or more 1.22, 95% confidence interval (CI) 0.96 to 1.55). For neonatal outcomes, our review showed both benefits and harms for late cord clamping. Following birth, there was a significant increase in infants needing phototherapy for jaundice (RR 0.59, 95% CI 0.38 to 0.92; five trials of 1762 infants) in the late compared with early clamping group. This was accompanied by significant increases in newborn haemoglobin levels in the late cord clamping group compared with early cord clamping (weighted mean difference 2.17 g/dL; 95% CI 0.28 to 4.06; three trials of 671 infants), although this effect did not persist past six months. Infant ferritin levels remained higher in the late clamping group than the early clamping group at six months.

AUTHORS' CONCLUSIONS

One definition of active management includes directions to administer an uterotonic with birth of the anterior shoulder of the baby and to clamp the umbilical cord within 30-60 seconds of birth of the baby (which is not always feasible in practice). In this review delaying clamping of the cord for at least two to three minutes seems not to increase the risk of postpartum haemorrhage. In addition, late cord clamping can be advantageous for the infant by improving iron status which may be of clinical value particularly in infants where access to good nutrition is poor, although delaying clamping increases the risk of jaundice requiring phototherapy.

A systematic review and meta-analysis of a brief delay in clamping the umbilical cord of preterm infants

BACKGROUND

The optimal timing of clamping the umbilical cord in preterm infants at birth is the subject of continuing debate.

OBJECTIVE

To investigate the effects of a brief delay in cord clamping on the outcome of babies born prematurely.

METHODS

A retrospective meta-analysis of randomised trials in preterm infants was conducted. Data were collected from published studies identified by a structured literature search in EMBASE, PubMed, CINAHL and the Cochrane Library. All infants born below 37 weeks gestation and enrolled into a randomised study of delayed cord clamping (30 s or more) versus immediate cord clamping (less than 20 s) after birth were included. Systematic search and analysis of the data were done according to the methodology of the Cochrane collaboration.

RESULTS

Ten studies describing a total of 454 preterm infants were identified which met the inclusion and assessment criteria. Major benefits of the intervention were higher circulating blood volume during the first 24 h of life, less need for blood transfusions (p = 0.004) and less incidence of intraventricular hemorrhage (p = 0.002).

CONCLUSIONS

The procedure of a delayed cord clamping time of at least 30 s is safe to use and does not compromise the preterm infant in the initial post-partum adaptation phase.

¿Pinzamiento precoz o tardío del cordón umbilical? Una revisión sistemática de la literatura médica

INTRODUCTION

There is wide variability in clinical practice in the moment of clamping the umbilical cord. Opinions in the medical community differ on the harm and/or benefits, both for the mother and for the newborn, of early versus late cord clamping. Currently, the debate among those who defend and/or criticize one or other of these practices continues. The aim of this study was to evaluate the effects of early versus late clamping of the umbilical cord in full-term newborns on maternal and neonatal outcomes.

MATERIAL AND METHODS

A literature search of randomized clinical trials was carried out in the Cochrane Library, MEDLINE and Lilacs. It was completed with a hand search of references in relevant articles. All randomized controlled clinical trials of good methodological quality that compared early versus late cord clamping in term newborns were selected.

RESULTS

Of seven identified studies, four had the required characteristics for inclusion in this systematic review. Comparison of early versus late clamping in these studies revealed that late clamping could diminish the prevalence of children with low iron reserves at 3 months of age by 50%, but this result comes from a study that lost more than 40% of the patients during follow-up. The results concerning anemia at 3 months of age showed statistical heterogeneity since the two studies that analyzed this outcome had opposite results. For other outcomes such as birth weight, Apgar < 5, and tachypnea the studies were too small for significant differences to be detected.

CONCLUSIONS

This review shows that there is no clear evidence for defending any of the modalities of cord clamping in full-term newborns. Further research is needed to identify the best moment for cord clamping.

Early versus delayed umbilical cord clamping in preterm infants

BACKGROUND

Optimal timing for clamping of the umbilical cord at birth is unclear. Early clamping allows for immediate resuscitation of the newborn. Delaying clamping may facilitate transfusion of blood between the placenta and the baby.

OBJECTIVES

To delineate the short- and long-term effects for infants born at less than 37 completed weeks' gestation, and their mothers, of early compared to delayed clamping of the umbilical cord at birth.

SEARCH STRATEGY

We searched the Cochrane Pregnancy and Childbirth Group trials register (2 February 2004), the Cochrane Neonatal Group trials register (2 February 2004), the Cochrane Central Register of Controlled Trials (The Cochrane Library, Issue 1, 2004), PubMed (1966 to 2 February 2004) and EMBASE (1974 to 2 February 2004).

SELECTION CRITERIA

Randomized controlled trials comparing early with delayed (30 seconds or more) clamping of the umbilical cord for infants born before 37 completed weeks' gestation.

DATA COLLECTION AND ANALYSIS

Three reviewers assessed eligibility and trial quality.

MAIN RESULTS

Seven studies (297 infants) were eligible for inclusion. The maximum delay in cord clamping was 120 seconds. Delayed cord clamping was associated with a higher hematocrit four hours after birth (four trials, 134 infants; weighted mean difference 5.31, 95% confidence interval (CI) 3.42 to 7.19), fewer transfusions for anaemia (three trials, 111 infants; relative risk (RR) 2.01, 95% CI 1.24 to 3.27) or low blood pressure (two trials, 58 infants; RR 2.58, 95% CI 1.17 to 5.67) and less intraventricular haemorrhage (five trials, 225 infants; RR 1.74, 95% CI 1.08 to 2.81) than early clamping.

REVIEWERS' CONCLUSIONS

Delaying cord clamping by 30 to 120 seconds, rather than early clamping, seems to be associated with less need for transfusion and less intraventricular haemorrhage. There are no clear differences in other outcomes.

Evaluation of the meta-analyses on the effects, on both mother and baby, of the various components of 'active' management of the third stage of labour

In their comprehensive review of controlled trials, Prendiville and Elbourne (1989) used the technique of meta-analysis to study the effects, on both mother and baby, of various aspects of third stage management, acknowledging some of the shortcomings of the trials used. This paper questions some of the conclusions which these authors drew and, drawing on other evidence (some of which has been published since the review), puts forward alternative interpretations of some of the meta-analyses. Reference is also made to the updated meta-analyses in the Cochrane Pregnancy and Childbirth Database (Elbourne, 1994a-h). In addition, this paper examines the extent to which the findings of the Bristol and Dublin third stage trials (Prendiville et al, 1988; Begley, 1990) add to our understanding of what is effective care during the third stage of labour.

Association of neonatal respiratory distress with birth asphyxia and deficiency of red cell mass in premature infants

Red cell mass (RCM) was estimated using 125I-labelled human serum albumin in 128 premature infants born after 26 to 36 weeks gestation. Infants of three different gestational periods (26--29, 30--32, and 33--36 weeks) with respiratory distress (RD) averaged lower one-minute Apgar scores and lower RCM than infants without RD (P less than 0.05). The incidence of RD was significantly (P less than 0.05) higher in infants with Apgar scores below 6 and in infants with RCM of less than 35 ml/kg than in the infants with greater values. The highest incidence of RD and the highest mortality rate were found in the infants with low Apgar scores and low RCM values. Prematures with similar Apgar scores showed a higher incidence of RD when RCM was low, and infants with similar RCM showed a higher incidence of RD when Apgar scores were low. Our results suggest that both birth asphyxia and deficiency of red cell mass interfere with postnatal cardio-respiratory adaptation. In high-risk premature infants, erythrocytes should be transfused when the venous haematocrit is below 0.459