Immediate and delayed cord clamping in infants born between 24 and 32 weeks: a pilot randomized controlled trial

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.

Rethinking placental transfusion and cord clamping issues

A brief delay in clamping the umbilical cord results in a placental transfusion that supplies the infant with a major source of iron during the first few months of life. Cord circulation continues for several minutes after birth and placental transfusion results in approximately 30% more blood volume. Gravity influences the amount of placental transfusion that an infant receives. Placing the infant skin-to-skin requires a longer delay of cord clamping (DCC) than current recommendations. Uterotonics are not contraindicated with DCC. Cord milking is a safe alternative to DCC when one must cut the cord prematurely. Recent randomized controlled trials demonstrate benefits for term and preterm infants from DCC. The belief that DCC causes hyperbilirubinemia or symptomatic polycythemia is unsupported by the available research. Delay of cord clamping substantively increases iron stores in early infancy. Inadequate iron stores in infancy may have an irreversible impact on the developing brain despite oral iron supplementation. Iron deficiency in infancy can lead to neurologic issues in older children including poor school performance, decreased cognitive abilities, and behavioral problems. The management of the umbilical cord in complex situations is inconsistent between birth settings. A change in practice requires collaboration between all types of providers who attend births.

Reinscribing the birthing body: homebirth as ritual performance

In this article, I examine the clinical practices engaged in by U.S. homebirth midwives and their clients from the beginning of pregnancy through to the immediate postpartum period, deconstructing them for their symbolic and ritual content. Using data collected from open-ended, semistructured interviews and intensive participant-observation, I describe the roles ritual plays in the construction, performance, and maintenance of birth at home as a transgressive rite of passage. As midwives ritually elaborate approaches to care to capitalize on their semiotic power to transmit a set of counterhegemonic values to participants, they are attempting, quite self-consciously, to peel away the fictions of medicalized birthing care. Their goal: to expose strong and capable women who "grow" and birth babies outside the regulatory and self-regulatory processes naturalized by modern, technocratic obstetrics. Homebirth practices are, thus, not simply evidence-based care strategies. They are intentionally manipulated rituals of technocratic subversion designed to reinscribe pregnant bodies and to reterritorialize childbirth spaces (home) and authorities (midwives and mothers).

Risk factors for isolated periventricular leukomalacia

Periventricular leukomalacia, a major cause of neurologic disabilities in preterm infants, can be isolated or associated with intraventricular and periventricular hemorrhage. To determine the risk factors for isolated periventricular leukomalacia, we retrospectively studied the characteristics of all very low birth weight infants affected by isolated periventricular leukomalacia who were delivered over a 5-year period and compared them with a control group of very low birth weight infants, matched within 2 weeks for gestational age, with no central nervous system pathology, and born during the same period. In total, 20 affected infants were compared with 98 control infants. Neonatal sepsis caused by coagulase-negative Staphylococcus (P = 0.014) and neonatal seizure (P = 0.026) were associated with isolated periventricular leukomalacia only on univariate analysis. Three variables demonstrated statistically significant associations with isolated periventricular leukomalacia on both univariate and multivariate logistic regression analysis as independent risk factors: birth weight (odds ratio, 4.31; 95% confidence interval, 1.54-12.06; P = 0.005), early neonatal hypotension requiring combined inotropic therapy (odds ratio, 4.90; 95% confidence interval; 1.22-19.68, P = 0.025), and delayed surgical closure of hemodynamically significant patent ductus arteriosus beyond age 7 days (odds ratio, 1.20; 95% confidence interval, 1.06-1.35; P = 0.003).

Effects of delayed cord clamping in very-low-birth-weight infants

OBJECTIVE

Delayed cord clamping (DCC) may be beneficial in very-preterm and very-low-birth-weight infants.

STUDY DESIGN

This study was a randomized unmasked controlled trial. It was performed at three centers of the NICHD (National Institute of Child Health and Human Development) Neonatal Research Network. DCC in very-preterm and very-low-birth-weight infants will result in an increase in hematocrit levels at 4 h of age. Infants with a gestational age of 24 to 28 weeks were randomized to either early cord clamping (<10 s) or DCC (30 to 45 s). The primary outcome was venous hematocrit at 4 h of age. Secondary outcomes included delivery room management, selected neonatal morbidities and the need for blood transfusion during the infants' hospital stay.

RESULT

A total of 33 infants were randomized: 17 to the immediate cord clamping group (cord clamped at 7.9±5.2 s, mean±s.d.) and 16 to the DCC (cord clamped at 35.2±10.1 s) group. Hematocrit was higher in the DCC group (45±8% vs 40±5%, P<0.05). The frequency of events during delivery room resuscitation was almost identical between the two groups. There was no difference in the hourly mean arterial blood pressure during the first 12 h of life; there was a trend in the difference in the incidence of selected neonatal morbidities, hematocrit at 2, 4 and 6 weeks, as well as the need for transfusion, but none of the differences was statistically significant.

CONCLUSION

A higher hematocrit is achieved by DCC in very-low-birth-weight infants, suggesting effective placental transfusion.

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.

Alternative positions for the baby at birth before clamping the umbilical cord

BACKGROUND

The third stage of labour is from birth of the baby until delivery of the placenta. Clamping the umbilical cord is one component of active management of the third stage. Deferring cord clamping allows blood flow between the baby and the placenta to continue; net transfer to the baby is called placental transfusion. If the cord is clamped immediately placental transfusion is restricted. Gravity is one of several factors that may influence the volume and duration of placental transfusion at both vaginal and caesarean births. Hence raising or lowering the baby whilst the cord is intact may influence placental transfusion, which in turn may affect outcome for the baby and the woman.

OBJECTIVES

To compare the effects of alternative positions for the baby between birth and cord clamping on outcome for the baby, outcome for the mother and on use of health service resources.

SEARCH STRATEGY

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (July 2010).

SELECTION CRITERIA

Randomised trials comparing alternative positions for the baby at vaginal and caesarean birth, before clamping of the umbilical cord.

DATA COLLECTION AND ANALYSIS

We independently assessed trial eligibility and quality. When necessary, we contacted study authors for additional information.

MAIN RESULTS

Thirty-seven studies (7559 mother-infant pairs) were excluded: 33 (7296) because they did not compare alternative positions for the baby before clamping the umbilical cord and four (263) due to quasi-random allocation. No studies met the inclusion criteria. One additional trial is ongoing.

AUTHORS' CONCLUSIONS

No randomised trials have assessed the influence of gravity on placental transfusion. Large, well-designed randomised trials are needed to assess whether gravity influences placental transfusion at vaginal and caesarean births and, if so, whether this affects short-term and long-term outcome for the baby and for the mother.

Umbilical cord blood acid-base and gas analysis after early versus delayed cord clamping in neonates at term

OBJECTIVE

To compare umbilical cord acid-base status and blood gas analysis between umbilical cords clamped within 10 s and at 2 min of delivery.

METHODS

A total of 158 healthy full-term mothers were randomly assigned to an early clamping (<10 s post-delivery, n = 79) or delayed clamping (2 min post-delivery, n = 79) group. After application of inclusion criteria, umbilical vein blood acid-base status and gases were analyzed in 65 early clamped and 51 delayed clamped cords. Fewer cases could be examined in the umbilical artery: 55 cords in the early clamping group and 44 in the delayed one.

RESULTS

Acid-base and gas analysis results did not significantly differ between the groups in the umbilical vein or umbilical artery, with the exception of a higher (p < 0.001) mean umbilical artery pO(2) value in the delayed versus early clamping group. No significant differences in umbilical vein or artery pCO(2) or HCO(3) (-) values were observed between the early and delayed clamp groups.

CONCLUSIONS

A delay of 2 min before umbilical cord clamping does not significantly change acid-base and gas analysis results, with the exception of a higher mean umbilical artery pO(2) value in the delayed clamping group.

Immunologic and infectious consequences of immediate versus delayed umbilical cord clamping in premature infants: a prospective, randomized, controlled study

AIM

To evaluate the immunologic and infectious consequences of delayed versus immediate cord clamping in premature infants (<35 weeks) during the neonatal period.

METHODS

This was a prospective, masked, randomized, controlled, single-center study. Prior to delivery 35 infants were randomly assigned to immediate cord clamping (ICC) at 5-10 s and 30 infants to delayed cord clamping (DCC), at 30-45 s (14 and 15 infants in each group were <1500 g, respectively).

RESULTS

Neonatal characteristics of the ICC and DCC groups were comparable. There was no significant difference between the ICC and DCC groups in the complement or in the immunoglobulin levels. All were within the normal range for age. All infectious parameters (events of sepsis or "rule-out sepsis", days of antibiotic therapy, and number of antibiotic courses during hospitalization and infections within the first month of life in cases of earlier discharge) were comparable in both groups. Similar results were found in the subgroup of infants <1500 g. Gender analysis showed only modest differences.

CONCLUSIONS

Delayed compared to immediate cord clamping did not affect the immunologic or the infectious status of infants born at <35 weeks during the neonatal period.

Seven-month developmental outcomes of very low birth weight infants enrolled in a randomized controlled trial of delayed versus immediate cord clamping

OBJECTIVE

The results from our previous trial revealed that infants with delayed cord clamping (DCC) had significantly lesser intraventricular hemorrhage (IVH) and late-onset sepsis (LOS) than infants with immediate cord clamping (ICC). A priori, we hypothesized that infants with DCC would have better motor function by 7 months corrected age.

STUDY DESIGN

Infants between 24 and 31 weeks were randomized to ICC or DCC and follow-up evaluation was completed at 7 months corrected age.

RESULT

We found no differences in the Bayley Scales of Infant Development (BSID) scores between the DCC and ICC groups. However, a regression model of effects of DCC on motor scores controlling for gestational age, IVH, bronchopulmonary dysplasia, sepsis and male gender suggested higher motor scores of male infants with DCC.

CONCLUSION

DCC at birth seems to be protective of very low birth weight male infants against motor disability at 7 months corrected age.

THIRD STAGE PRACTICES AND THE NEONATE

The third stage of labour is defined as the period following the completed delivery of the newborn until the completed delivery of the placenta and its attached membranes. Whilst to the exhausted labouring woman this stage may be an afterthought, it is a crucial time for fetal-to-neonatal transition. Major changes in anatomy and physiology occur in both mother and baby. It has also been described as ‘potentially the most hazardous part of childbirth, largely due to the risk of postpartum haemorrhage (PPH) on placental separation. Despite this, the current management guidelines are based on an ‘eclectic combination of historical, anecdotal, philosophical and research-based factors.

Effect of placental transfusion on the blood volume and clinical outcome of infants born by cesarean section

Delay in cord clamping up to 30 to 40 seconds is feasible and should be practiced in preterm and term infants born by cesarean section. In term infants, this maneuver may decrease iron deficiency anemia at 6 months of age. Premature infants may have a higher blood volume and hematocrit initially requiring fewer transfusions. They also have a decreased incidence of intraventricular hemorrhage. The effect of compounding factors, such as maternal blood pressure, uterine contraction, medications, bleeding, and their effects on the infant's immediate and long-term outcome are unclear.

Umbilical cord milking reduces the need for red cell transfusions and improves neonatal adaptation in infants born at less than 29 weeks' gestation: a randomised controlled trial

OBJECTIVE

To investigate the effects of umbilical cord milking on the need for red blood cell (RBC) transfusion and morbidity in very preterm infants.

PATIENTS AND METHODS

40 singleton infants born between 24 and 28 weeks' gestation were randomly assigned to receive umbilical cord clamped either immediately (control group, n = 20) or after umbilical cord milking (milked group, n = 20). Primary outcome measures were the probability of not needing transfusion, determined by Kaplan-Meier analysis, and the total number of RBC transfusions. Secondary outcome variables were haemoglobin value and blood pressure at admission.

RESULTS

There were no significant differences in gestational age and birth weight between the two groups. The milked group was more likely not to have needed red cell transfusion (p = 0.02) and had a decreased number (mean (SD)) of RBC transfusions (milked group 1.7 (3.0) vs controls 4.0 (4.2); p = 0.02). The initial mean (SD) haemoglobin value was higher in the milked group (165 (14) g/l) than in the controls (141 (16) g/l); p<0.01). Mean (SD) blood pressure at admission was significantly higher in the milked group (34 (9) mm Hg) than in the controls 28 (8) mm Hg; p = 0.03). There was no significant difference in mortality between the groups. The milked group had a shorter duration of ventilation or supplemental oxygen than the control group.

CONCLUSION

Milking the umbilical cord is a safe procedure, reducing the need for RBC transfusions, and the need for circulatory and respiratory support in very preterm infants.

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.

Delayed cord clamping in preterm infants delivered at 34 36 weeks' gestation: a randomised controlled trial

BACKGROUND

Even mild iron deficiency and anaemia in infancy may be associated with cognitive deficits. A delay in clamping the cord improves haematocrit levels and results in greater vascular stability and less need for packed cell transfusions for anaemia in the first period after birth. Follow-up data on haemoglobin levels after the neonatal period were not available.

OBJECTIVE

To provide neonatal and follow-up data for the effects of early or delayed clamping of the cord.

METHODS

37 premature infants (gestational age 34 weeks, 0 days-36 weeks, 6 days) were randomly assigned to one of two groups in the first hour after birth, and at 10 weeks of age. In one group the umbilical cord was clamped within 30 seconds (mean (SD) 13.4 (5.6)) and in the other, it was clamped at 3 minutes after delivery. In the neonatal period blood glucose and haemoglobin levels were determined. At 10 weeks of age haemoglobin and ferritin levels were determined.

RESULTS

The late cord-clamped group showed consistently higher haemoglobin levels than the early cord-clamped group, both at the age of 1 hour (mean (SD) 13.4 (1.9) mmol/l vs 11.1 (1.7) mmol/l), and at 10 weeks (6.7 (0.75) mmol/l vs 6.0 (0.65) mmol/l). No relationship between delayed clamping of the umbilical cord and pathological jaundice or polycythaemia was found.

CONCLUSION

Immediate clamping of the umbilical cord should be discouraged.

Timing of cord clamping revisited

Although cord cutting has been performed since the beginning of mankind, the timing and advantages of early versus delayed cord clamping are still controversial. Early cord clamping (within the first 30 s after birth) is usually justified for potential prevention of postpartum hemorrhage and for immediate treatment of the newborn, but at the same time, may increase Rh-sensitization. Delayed cord clamping is performed after a period of 30 s during which 'placental transfusion' of approximately 80 mL of blood occurs. This amount seems to protect the baby from childhood anemia without increasing hypervolemia-related risks. In preterm infants, delayed clamping appears to reduce the risk of intraventricular hemorrhage and the need for neonatal transfusion. Obtaining cord blood for future autologous transplantation of stem cells needs early clamping and seems to conflict with the infant's best interest. Although a tailored approach is required in the case of cord clamping, the balance of available data suggests that delayed cord clamping should be the method of choice.

Delayed umbilical cord clamping for reducing anaemia in low birthweight infants: implications for developing countries

BACKGROUND

Cheap and effective interventions are needed to reduce the risk of infant anaemia in developing countries. Delayed cord clamping (DCC) has been shown to be a simple, safe and cost-free delivery procedure that augments red cell mass in appropriate-for-gestational-age term and preterm infants. It is not known, however, whether DCC is similarly safe and effective in small-for-gestational-age (SGA) infants. We analysed the available evidence to generate a balanced inference on the use of DCC in developing countries.

OBJECTIVES

To examine the short- and long-term effects in SGA infants of DCC compared with immediate clamping, and to assess the relationship between time of clamping and the potential postnatal haematological complications of DCC in SGA infants.

SEARCH STRATEGY

PubMed (1966 to January 2006), EMBASE (1988 to January 2006) and The Cochrane Library (Issue 1, 2006) were searched. Reference lists of published trials were examined and major journals of perinatal and tropical medicine were hand-searched.

SELECTION CRITERIA

Randomised and quasi-randomised trials comparing delayed with immediate cord clamping in infants born between 30 and 42 completed weeks of gestation and which included a proportion of SGA infants.

DATA COLLECTION AND ANALYSIS

Three reviewers assessed eligibility and trial quality.

MAIN RESULTS

To date, no trials have specifically reported the effects of DCC in SGA infants. Three trials were included, of 190 term and 40 preterm infants, a proportion of whom were SGA. DCC was associated with higher haemoglobin levels in term infants at follow-up [two trials, 127 infants, weighted mean difference (WMD) 9.17 g/L, 95% confidence interval (CI) 5.94-12.40]. In preterm infants, the proportion who required a blood transfusion in the 1st 6 weeks after birth was lower after DCC (one trial, 38 infants, RR 0.56, 95% CI 0.34-0.94). It was not possible to infer from the available data whether SGA infants were at greater risk of adverse effects in the early neonatal period.

CONCLUSIONS

DCC in a group that contains both AGA and SGA infants was associated with higher haemoglobin levels at 2-3 months of age in term infants and a reduction in the number of blood transfusions needed in the 1st 4- 6 weeks of life in preterm infants. No reliable conclusions could be drawn about the potential adverse effects of DCC. The paucity of information on DCC in SGA infants justifies further research, especially in developing countries where the baseline risk for polycythaemia-hyperviscosity syndrome is likely to be lower than in industrialised countries.

Delayed cord clamping in very preterm infants reduces the incidence of intraventricular hemorrhage and late-onset sepsis: a randomized, controlled trial

OBJECTIVE

This study compared the effects of immediate (ICC) and delayed (DCC) cord clamping on very low birth weight (VLBW) infants on 2 primary variables: bronchopulmonary dysplasia (BPD) and suspected necrotizing enterocolitis (SNEC). Other outcome variables were late-onset sepsis (LOS) and intraventricular hemorrhage (IVH).

STUDY DESIGN

This was a randomized, controlled unmasked trial in which women in labor with singleton fetuses <32 weeks' gestation were randomly assigned to ICC (cord clamped at 5-10 seconds) or DCC (30-45 seconds) groups. Women were excluded for the following reasons: their obstetrician refused to participate, major congenital anomalies, multiple gestations, intent to withhold care, severe maternal illnesses, placenta abruption or previa, or rapid delivery after admission.

RESULTS

Seventy-two mother/infant pairs were randomized. Infants in the ICC and DCC groups weighed 1151 and 1175 g, and mean gestational ages were 28.2 and 28.3 weeks, respectively. Analyses revealed no difference in maternal and infant demographic, clinical, and safety variables. There were no differences in the incidence of our primary outcomes (BPD and suspected NEC). However, significant differences were found between the ICC and DCC groups in the rates of IVH and LOS. Two of the 23 male infants in the DCC group had IVH versus 8 of the 19 in the ICC group. No cases of sepsis occurred in the 23 boys in the DCC group, whereas 6 of the 19 boys in the ICC group had confirmed sepsis. There was a trend toward higher initial hematocrit in the infants in the DCC group.

CONCLUSIONS

Delayed cord clamping seems to protect VLBW infants from IVH and LOS, especially for male infants.

Neonatal resuscitation where resources are limited

This article reviews neonatal resuscitation techniques that can be used where resources are limited. The topic of delayed cord clamping is discussed in detail as an example of an evidence evaluation in which an important segment of the research has been conducted in developing countries. Thermal protection, clearing the airway, and assisted ventilation are discussed as areas in which some evidence exists from research in the developing world, but more work is needed to bring the full benefit of appropriate intervention to newborns in settings where resources are limited.

Infants' blood volume in a controlled trial of placental transfusion at preterm delivery

OBJECTIVE

To investigate whether it was possible to promote placental blood transfer to infants at preterm delivery by (1) delaying cord clamping, (2) holding the infant below the placenta, and (3) administering an oxytocic agent to the mother, we measured the infants' blood volumes.

DESIGN

Randomized study.

METHODS

Forty-six preterm infants (gestational age: 24[0/7] to 32[6/7] weeks) were assigned randomly to either placental blood transfer promotion (delayed cord clamping [DCC] group, ie, > or =30 seconds from moment of delivery) or early cord clamping (ECC) with conventional management (ECC group). Eleven of 23 and 9 of 23 infants assigned randomly to DCC and ECC, respectively, were delivered through the vaginal route. The study was conducted at a tertiary perinatal center, the Queen Mother's Hospital (Glasgow, United Kingdom).

RESULTS

The infants' mean blood volume in the DCC group (74.4 mL/kg) was significantly greater than that in the ECC group (62.7 mL/kg; 95% confidence interval for advantage: 5.8-17.5). The blood volume was significantly increased by DCC for infants delivered vaginally. The infants in the DCC group delivered through cesarean section had greater blood volumes (mean: 70.4 mL/kg; range: 45-83 mL/kg), compared with the ECC group (mean: 64.0 mL/kg; range: 48-77 mL/kg), but this was not significant. Additional analyses confirmed the effect of DCC (at least 30 seconds) to increase average blood volumes across the full range of gestational ages studied.

CONCLUSIONS

The blood volume was, on average, increased in the DCC group after at least a 30-second delay for both vaginal and cesarean deliveries. However, on average, euvolemia was not attained with the third stage management methods outlined above.

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.