Effect of Placental Transfusion on Long-Term Neurodevelopmental Outcomes in Premature Infants: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

BACKGROUND

The pathophysiology and the potential risks of placental transfusion (PT) differ substantially in preterm infants, necessitating specific studies in this population. This study aimed to evaluate the safety and efficacy of PT in preterm infants from the perspective of long-term neurodevelopmental outcomes.

METHODS

We conducted a systematic literature search using placental transfusion, preterm infant, and its synonyms as search terms. Cochrane Central Register of Controlled Trials, Medline, and Embase were searched until March 07, 2023. Two reviewers independently identified, extracted relevant randomized controlled trials, and appraised the risk of bias. The extracted studies were included in the meta-analysis of long-term neurodevelopmental clinical outcomes using fixed-effects models.

RESULTS

A total of 5612 articles were identified, and seven randomized controlled trials involving 2551 infants were included in our meta-analysis. Compared with immediate cord clamping (ICC), PT may not impact adverse neurodevelopment events. No clear evidence was found of a difference in the risk of neurodevelopmental impairment (risk ratio [RR]: 0.89, 95% confidence interval [CI]: 0.76 to 1.03, P = 0.13, I2 = 0). PT was not associated with the incidence of cerebral palsy (RR: 1.23, 95% CI: 0.59 to 2.57, P = 0.79, I2 = 0). Analyses showed no differences between the two interventions in cognitive, language, and motor domains of neurodevelopment.

CONCLUSIONS

From the perspective of long-term neurodevelopment, PT at preterm birth may be as safe as ICC. Future studies should focus on standardized, high-quality clinical trials and individual participant data to optimize cord management strategies for preterm infants after birth.

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.

Cut umbilical cord milking (C-UCM) as a mode of placental transfusion in non-vigorous preterm neonates: a randomized controlled trial

Routine practice of delayed cord clamping (DCC) is the standard of care in vigorous neonates. However there is no consensus on the recommended approach to placental transfusion in non-vigorous neonates. In this trial, we tried to examine the effect of cut umbilical cord milking (C-UCM) as compared to early cord clamping (ECC) on hematological and clinical hemodynamic parameters in non-vigorous preterm neonates of 30-35 weeks gestation. The primary outcome assessed was venous hematocrit (Hct) at 48 (± 4) hours of postnatal age. The important secondary outcomes assessed were serum ferritin at 6 weeks of age, mean blood pressure in the initial transitional phase along with important neonatal morbidities and potential complications. In this single centre randomized controlled trial, 134 non vigorous neonates of 30-35 weeks gestation were allocated in a 1:1 ratio to either C-UCM (n = 67) or ECC (n = 67). For statistical analysis, unpaired Student t and Chi square or Fisher's exact test were used. The mean Hct at 48 h was higher in the C-UCM group as compared to the control group, 50.24(4.200) vs 46.16(2.957), p < .0001. Also significantly higher was the mean Hct at 12 h, 6 weeks and mean serum ferritin at 6 weeks of age in the milked group (p < .0001). Mean blood pressure at 1 h and 6 h was also significantly higher in the milked arm. Need for transfusion and inotropes was less in the milked group but not statistically significant. No significant difference in potential complications was observed between the groups.    Conclusion: C-UCM stabilizes initial blood pressure and results in higher hematocrit and improved iron stores. It can be an alternative to DCC in non-vigorous preterm neonates of 30-35 weeks' gestation. Further large multicentric studies are needed to fully establish its efficacy and safety.   Trial registration: CTRI/2021/12/038606; registration date December 14, 2021. What is Known: • DCC is the routinely recommended method of placental transfusion for vigorous neonates but no consensus exist for neonates requiring resuscitation at birth. • C-UCM is easier to perform in non-vigorous neonates but there is paucity of studies in the preterm population. What is New: • C-UCM is effective as well as safe in non-vigorous preterm neonates of 30-35 weeks gestational age. • C-UCM holds promise as an alternative to DCC, especially in resource limited settings and in situations where the later is not feasible.

To guide future practice, perinatal trials should be much larger, simpler and less fragile with close to 100% ascertainment of mortality and other key outcomes

The Australian Placental Transfusion Study (APTS) randomised 1,634 fetuses to delayed (≥60 s) versus immediate (≤10 s) clamping of the umbilical cord. Systematic reviews with meta-analyses, including this and similar trials, show that delaying clamping in preterm infants reduces mortality and need for blood transfusions. Amongst 1,531 infants in APTS followed up at two years, aiming to delay clamping for 60 s or more reduced the relative risk of the primary composite outcome of death or disability by 17% (p = 0.01). However, this result is fragile because nominal statistical significance (p < 0.05) would be abolished by only 2 patients switching from a non-event to an event, and the primary composite outcome was missing in 112 patients (7%). To achieve more robust evidence, any future trials should emulate the large, simple trials co-ordinated from Oxford which reliably identified moderate, incremental improvements in mortality in tens of thousands of participants, with <1% missing data. Those who fund, regulate, and conduct trials that aim to change practice should repay the trust of those who consent to participate by doing everything possible to minimise missing data for key outcomes.

Premature infants receiving delayed cord clamping with and without cord milking: a randomized control trial

BACKGROUND

Preterm infants often have long hospital stays and frequent blood tests; they often develop anemia requiring multiple blood transfusions. Placental transfusion via delayed cord clamping (DCC) or umbilical cord milking (UCM) helps increase blood volume. We hypothesized umbilical cord milking (UCM), together with DCC, would be superior in reducing blood transfusions.

OBJECTIVES

To compare the effects of DCC and DCC combined with UCM on hematologic outcomes among preterm infants.

METHODS

One hundred twenty singleton preterm infants born at 280/7- 336/7 weeks of gestation at Thammasat University Hospital were enrolled in an open-label, randomized, controlled trial. They were placed into three groups (1:1:1) by a block-of-three randomization: DCC for 45 s, DCC with UCM performed before clamping (DCM-B), and DCC with UCM performed after clamping (DCM-A). The primary outcomes were hematocrit levels and number of infants receiving blood transfusions during the first 28 days of life. Intraventricular hemorrhage (IVH) and necrotizing enterocolitis (NEC) were secondary outcomes. Analyses were performed with an intent-to-treat approach.

RESULTS

One hundred twenty preterm infants were randomized. There was no statistically significant difference in neonatal outcomes; hematocrit on admission 54.0 ± 5.5, 53.3 ± 6.0, and 54.3 ± 5.8 (p = 0.88), receiving blood transfusions 25%, 20%, and 12.5% (p = 0.24), incidence of NEC 7.5, 0 and 10% (p = 0.78) in the DCC, DCM-B and DCM-A groups, respectively. There were no preterm infants with severe IVH, polycythemia, maternal or neonatal death.

CONCLUSION

The placental transfusion techniques utilized, DCC and DCC combined with UCM, provided the same benefits for preterm infants born at GA 28 and 33 weeks in terms of reducing the need for RBC transfusions, severities of IVH and incidence of NEC without increasing comorbidity.

TRIAL REGISTRATION

TCTR20190131002 . Registered 31 January 2019-Retrospectively registered.

Delayed cord clamping during deliveries with meconium-stained amniotic fluid

In this cohort study of deliveries affected with meconium, the perinatal factors that were significantly associated with non-performance of delayed cord clamping were primigravida, maternal diabetes, chorioamnionitis, rupture of membranes ≥18 h, assisted vaginal delivery, cesarean section, breech presentation, thick meconium, fetal distress and nonvigorous status of the newborn.

The hematological impact of umbilical cord milking versus delayed cord clamping in premature neonates: a randomized controlled trial

BACKGROUND

The hematological impact of umbilical cord milking (UCM) was compared to that of delayed cord clamping (DCC) as a faster placental transfusion technique for preterm neonates (between 24 and 34 + 6 weeks gestation). A comparison of important neonatal morbidities was also made.

METHODS

This was an open-label randomized trial conducted from June 8, 2017, to April 22, 2019. Two hundred patients with preterm deliveries (24 and 34 + 6 weeks gestation) were assigned to the DCC or UCM group at random at a ratio of 1:1. The study power was 80% for a difference in the hematocrit value of 3% and Hb value of one gram, and an alpha error of 0.05.

RESULTS

The following variables were analyzed in the comparison of UCM vs. DCC: first draw hemoglobin: 17.0 ± 1.9 vs. 16.8 ± 1.8 gm/dl (95% CI -0.75-0.29, P 0.383); first draw hematocrit: 55.6 ± 6.4 vs. 55.2 ± 6.4% (95% CI -2.18-1.38, P 0.659); peak hematocrit: 56.9 ± 6.4 vs. 56.3 ± 6.7% (95% CI -2.41-1.26, P 0.537); the need for respiratory assistance (47% vs. 30%, P 0.020), inotropes (16% vs. 6%, P 0.040), and blood transfusion (26% vs. 12%, P 0.018); and the occurrence of intraventricular hemorrhage (9% vs. 5%, P 0.407), necrotizing enterocolitis (6% vs. 2%, P 0.279), sepsis (25% vs. 15%, P 0.111), and neonatal death (13% vs. 4%, P 0.40).

CONCLUSION

UCM facilitated a rapid transfer of placental blood equivalent to that of DCC for premature neonates. However, it resulted in increased rates of interventions and morbidities, especially in extremely preterm neonates.

TRIAL REGISTRATION

The clinical trial was registered on May 10, 2017, with registration number (NCT03147846).

A hybrid type I, multi-center randomized controlled trial to study the implementation of a method for Sustained cord circulation And VEntilation (the SAVE-method) of late preterm and term neonates: a study protocol

BACKGROUND

An intact umbilical cord allows the physiological transfusion of blood from the placenta to the neonate, which reduces infant iron deficiency and is associated with improved development during early childhood. The implementation of delayed cord clamping practice varies depending on mode of delivery, as well as gestational age and neonatal compromise. Emerging evidence shows that infants requiring resuscitation would benefit if respiratory support were provided with the umbilical cord intact. Common barriers to providing intact cord resuscitation is the availability of neonatal resuscitation equipment close to the mother, organizational readiness for change as well as attitudes and beliefs about placental transfusion within the multidisciplinary team. Hence, clinical evaluations of cord clamping practice should include implementation outcomes in order to develop strategies for optimal cord management practice.

METHODS

The Sustained cord circulation And Ventilation (SAVE) study is a hybrid type I randomized controlled study combining the evaluation of clinical outcomes with implementation and health service outcomes. In phase I of the study, a method for providing in-bed intact cord resuscitation was developed, in phase II of the study the intervention was adapted to be used in multiple settings. In phase III of the study, a full-scale multicenter study will be initiated with concurrent evaluation of clinical, implementation and health service outcomes. Clinical data on neonatal outcomes will be recorded at the labor and neonatal units. Implementation outcomes will be collected from electronic surveys sent to parents as well as staff and managers within the birth and neonatal units. Descriptive and comparative statistics and regression modelling will be used for analysis. Quantitative data will be supplemented by qualitative methods using a thematic analysis with an inductive approach.

DISCUSSION

The SAVE study enables the safe development and evaluation of a method for intact cord resuscitation in a multicenter trial. The study identifies barriers and facilitators for intact cord resuscitation. The knowledge provided from the study will be of benefit for the development of cord clamping practice in different challenging clinical settings and provide evidence for development of clinical guidelines regarding optimal cord clamping.

TRIAL REGISTRATION

Clinicaltrials.gov, NCT04070560 . Registered 28 August 2019.

[Influence of umbilical cord milking versus delayed cord clamping on the early prognosis of preterm infants with a gestational age of <34 weeks: a Meta analysis]

OBJECTIVES

To study the influence of umbilical cord milking versus delayed cord clamping on the early prognosis of preterm infants with a gestational age of <34 weeks.

METHODS

PubMed, Web of Science, Embase, the Cochrane Library, CINAHL, China National Knowledge Infrastructure, Wanfang Data, Weipu Database, and SinoMed were searched for randomized controlled trials on umbilical cord milking versus delayed cord clamping in preterm infants with a gestational age of <34 weeks published up to November 2021. According to the inclusion and exclusion criteria, two researchers independently performed literature screening, quality evaluation, and data extraction. Review Manger 5.4 was used for Meta analysis.

RESULTS

A total of 11 articles were included in the analysis, with 1 621 preterm infants in total, among whom there were 809 infants in the umbilical cord milking group and 812 in the delayed cord clamping group. The Meta analysis showed that compared with delayed cord clamping, umbilical cord milking increased the mean blood pressure after birth (weighted mean difference=3.61, 95%CI: 0.73-6.50, P=0.01), but it also increased the incidence rate of severe intraventricular hemorrhage (RR=1.83, 95%CI: 1.08-3.09, P=0.02). There were no significant differences between the two groups in hemoglobin, hematocrit, blood transfusion rate, proportion of infants undergoing phototherapy, bilirubin peak, and incidence rates of complications such as periventricular leukomalacia and necrotizing enterocolitis (P>0.05).

CONCLUSIONS

Compared with delayed cord clamping, umbilical cord milking may increase the risk of severe intraventricular hemorrhage in preterm infants with a gestational age of <34 weeks; however, more high-quality large-sample randomized controlled trials are needed for further confirmation.

Barriers to implementation of placental transfusion of babies at birth in Zambia

Delayed cord clamping (DCC) and umbilical cord milking (CM) have many benefits. However, a previous study done in Zambia showed that it was not a common practice among midwives. This study investigated possible barriers to DCC and CM, at the University Teaching Hospital in Lusaka. This was a qualitative study. A convenience sample was chosen, and snowball sampling was used. The midwives were interviewed using semi-structured interviews. Burnard's method of thematic content analysis was used. Through 14 interviews it became clear that the midwives were aware of DCC and used it whenever possible. The participants reported that the main barriers were the high workload and a variation in knowledge. A lack of facilities, such as heaters and resuscitation equipment in the delivery room also led to earlier cord clamping. The midwives were motivated to continue improving the routines. They expressed a need for more training as well as equipment and resources to facilitate DCC.

A 20-cm cut umbilical cord milking may not benefit the preterm infants < 30 week's gestation: A randomized clinical trial

BACKGROUND/PURPOSE

To evaluate whether a shorter length (20 cm) of C-UCM has potential benefits, compared to immediate cord clamping (ICC), in very preterm babies.

METHODS

Inborn preterm infants less than 30 weeks of gestational age (GA) were randomly assigned to the 20-cm C-UMC and ICC groups. The primary outcome was the need for packed red blood cell (pRBC) transfusion before the 21st day of life. The secondary outcomes were short- and long-term outcomes related to premature birth.

RESULTS

Seventy-six neonates were randomized to the two groups. GA were 27.2 ± 1.8 and 27.5 ± 1.7 weeks (p = 0.389) and birth weights were 987 ± 269 and 1023 ± 313 g (p = 0.601) in the 20-cm C-UCM and ICC groups, respectively. There was no significant difference between the groups in terms of the need for pRBC transfusion before the 21st day of life (59.4% versus 71.8%, adjusted odds ratio [aOR] 0.311, 95% confidence interval [CI] 0.090-1.079). An increased prevalence of late-onset sepsis was observed in the 20-cm C-UCM group compared to the ICC group (21.6% versus 5.1%, aOR 5.434, 95% CI 1.033-23.580). The mortality rates were 13.5% and 2.6% in the 20-cm C-UCM and ICC groups, respectively (aOR 5.339, 95% CI 0.563-50.626). The neurodevelopmental outcomes at 2 years of corrected age between the groups were also not statistically significant.

CONCLUSION

A 20-cm C-UCM showed no effect on reducing the incidence of pRBC transfusion in preterm babies with GA less than 30 weeks compared with ICC in this small-scale randomized controlled trial.

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.

A 3-armed multicenter randomized controlled trial: Placental Transfusion in Very Preterm Infants (PT-VPI)

Preterm infants constitute an important proportion of neonatal deaths and various complications, and very preterm infants (VPI) are more likely to develop severe complications, such as intraventricular hemorrhage (IVH), anemia, and sepsis. It has been confirmed that placental transfusion can supplement blood volume in infants and reduce preterm-associated complications, which is further conducive to the development of the nervous system and a better long-term prognosis. Based on these advantages, placental transfusion has been widely used in VPI. There are three main types of placental transfusion: delayed cord clamping (DCC), intact umbilical cord milking (I-UCM), and cut umbilical cord milking (C-UCM). However, the optimal method for PT-VPI remains controversial, and it is urgent to identify the best method of placental transfusion. We plan to fully evaluate the safety and effectiveness of these three placental transfusion methods in VPI in a 3-arm multicenter randomized controlled trial: Placental Transfusion in Very Preterm Infants (PT-VPI). Trial registration: chictr.org.cn, number ChiCTR2000030953.

A new wrinkle: Umbilical cord management (how, when, who)

In the past five years, umbilical cord management in both term and preterm infants has come full circle, going from the vast majority of infants receiving immediate cord clamping to virtually all governing organizations promoting placental transfusion, mainly in the form of delayed cord clamping (DCC). Placental transfusion refers to the transfer of more blood components to the infant during the first few minutes after birth. The different strategies for ensuring placental transfusion to the baby include delayed (deferred) cord clamping, milking of the attached cord before clamping, and milking of the cut cord. In this review, we address the current evidence to date for providing placental transfusion in different circumstances and the methods for implementation. We also highlight the gaps in knowledge and areas for future research.

Effect of delayed cord clamping on very preterm twins

BACKGROUND

The very preterm infants of twin births may particularly benefit from delayed cord clamping (DCC) as the likelihood of unfavorable outcome is greater compared to singletons. Unfortunately, there is paucity of available information regarding safety and efficacy of DCC in this group.

OBJECTIVE

To report the clinical consequences of delayed cord clamping (DCC) in very preterm twins, born between 23^0/7 and 31^6/7 weeks gestation.

STUDY DESIGN

In this pre and post intervention retrospective cohort study, we compared 30 very preterm infants born from 15 twin deliveries during historic study period to 32 very preterm infants born from 16 twin deliveries during DCC study period. During historic study period (August 19, 2013 to January 31, 2015), infants included were eligible to receive DCC, but their cords were immediately clamped. DCC study period (February 1, 2015 to January 31, 2017) included infants who had DCC performed for 60 s after birth.

RESULTS

The Apgar scores and other resuscitation variables were similar between both groups. After adjusting for gestational age and mode of delivery, significantly fewer infants in the DCC cohort needed red blood cell (RBC) transfusions in first week of life compared to the historic cohort (15.6% vs. 43.3%; P = 0.03). Death and other major neonatal outcomes were similar between both groups.

CONCLUSION

DCC in very preterm twins was safe, feasible and not associated with any adverse neonatal outcomes compared to early cord clamping. DCC was associated with a significant reduction in early RBC transfusions.

Umbilical cord milking in preterm neonates requiring resuscitation: A randomized controlled trial

OBJECTIVE

To evaluate the effect of cord milking on short term morbidity and hematologic parameters at 6 weeks in preterm neonates requiring resuscitation.

METHODS

This trial randomized preterm infants requiring resuscitation to milking group and no milking group. Multiple pregnancy, Rh negative mothers, hydrops, cord abnormalities were excluded. The primary outcome was hemoglobin and serum ferritin at 6 weeks of life. Secondary outcomes were common preterm morbidities and mortality.

RESULTS

60 neonates were included in the study. Infants in the milking group had higher hemoglobin (10.07 g/dl vs 8.9 g/dl; p 0.003) and higher serum ferritin level (244.8 ng/ml vs 148.5 ng/ml; p 0.04) compared to no milking group.

CONCLUSIONS

In preterm neonates requiring resuscitation, umbilical cord milking results in higher hemoglobin and ferritin at 6 weeks of life. It can be a used as a placental transfusion strategy in preterm neonates requiring resuscitation with no significant adverse effects.

CLINICAL TRIAL REGISTRATION

Clinical trials registry -India CTRI/2015/01/005436, www.ctri.nic.in.

Effect of delay in cord clamping 45 versus 60 s on very preterm singleton infants

BACKGROUND

In the range of timing suggested by American College of Obstetricians and Gynecologists 30 to 60 s, preterm infants may potentially derive more short and long-term benefits with delayed cord clamping (DCC) for at least 60 s. However, there are concerns with longer resuscitation delay in this vulnerable population.

OBJECTIVE

To compare the clinical consequences of 45 versus 60 s delay in umbilical cord clamping in singleton infants born between 23^0/7 to 31^6/7 weeks gestation.

STUDY DESIGN

We implemented DCC process in very preterm singleton infants, initially for 45 s and later, modified the policy to increase the delay to 60 s. We compared the infants born and received DCC (n = 60) during the 45 s study period (DCC-45 cohort), from Aug.19, 2013, to Aug.18, 2014 to the infants born and received DCC (n = 63) during the 60 s study period (DCC-60 cohort), from Feb.1, 2015, to Jan.31, 2016.

RESULTS

The incidence of necrotizing enterocolitis in DCC-60 cohort was 0% compared to 8% in the DCC-45 cohort (P = 0.02). Similarly, incidence of culture-positive sepsis was significantly lower in the DCC-60 cohort compared to DCC-45 cohort (8% versus 18%; P = 0.04). Incidence of mortality and other major morbidities were similar between both groups. Length of stay was significantly lower in DCC-60 cohort compared to DCC-45 cohort.

CONCLUSION

DCC for 60 s in very preterm singleton infants was safe, feasible and not associated with any adverse maternal or neonatal short-term outcomes compared to DCC for 45 s.

Effect of Placental Transfusion on Iron Stores in Moderately Preterm Neonates of 30-33 weeks Gestation

OBJECTIVE

To assess the effect of placental transfusion by delayed cord clamping (DCC) of 60 s or cord milking (CM) on serum ferritin levels at hospital discharge and 3 mo of postmenstrual age (PMA) in preterm neonates of 30 to 33 wk gestation in comparison to early cord clamping (ECC) within 10 s.

METHODS

This mixed longitudinal study was conducted in moderately preterm neonates of 30 to 33 wk gestation born in a level III unit in Northern India with the study sample nested within a randomized controlled trial on placental transfusion. Intervention was delayed cord clamping for 60 s or cord milking compared with early cord clamping (within 10 s). Primary outcome measure was serum ferritin levels at discharge. Secondary outcome measures were serum ferritin levels at 3 mo PMA, incidence of anemia, need for blood transfusion and incidence of iron deficiency by 3 mo PMA.

RESULTS

Out of the 215 randomly chosen infants, serum ferritin levels were estimated at least at one time point (at discharge or at 3 mo PMA) in 197 neonates [placental transfusion - 107; early cord clamping - 90]. Amongst them, ferritin level was estimated at discharge in 141 neonates, at 3 mo PMA in 76 neonates and at both time points in 20 neonates. Median (IQR) serum ferritin (μg/L) at discharge was significantly higher in placental transfusion group in comparison to the ECC group [399 (309,600) (n = 79) vs. 254 (190,311) (n = 62); p < 0.001]. Median (IQR) ferritin level at 3 mo PMA was not different between the study groups [20 (14,57) (n = 39) vs. 24 (8,52) (n = 37); p = 0.2]. The incidence of anemia by 3 mo PMA was significantly lesser in the placental transfusion group. No difference was observed in anemia requiring blood transfusion and iron deficiency by 3 mo PMA between the groups.

CONCLUSIONS

In 30 to 33 wk preterm neonates, placental transfusion resulted in significantly higher serum ferritin at discharge in comparison to early cord clamping. However, this benefit did not persist till 3 mo PMA.

Red Blood Cell Transfusion in Preterm Infants: Current Evidence and Controversies

The current evidence regarding the indication, advantages and risks of red blood cell transfusion (RBCT) for preterm infants is discussed. This is an important area in Neonatology to be examined given that 90% of extremely low birth weight infants receive RBCT and many controversies remain regarding when to transfuse and the risks of RBCT. The various treatment thresholds and guidelines used are presented and we compare the short-term clinical benefits of liberal and restrictive RBCT in preterm infants; the majority of these are equivocal and sadly long-term outcome data is limited. The latest evidence on how anaemia and blood transfusion affect organ perfusion in preterm infants is presented. This is important when trying to establish the optimal trigger threshold for RBCT in preterm infants, especially because the knowledge about the adaptive physiological responses to anaemia in very low birth weight infants and the effects of RBCT at various levels of anaemia is also inadequate. Further research into the physiological adaptive response to anaemia of varying degrees and to RBCT at different levels of anaemia in preterm infants of different gestational and post-natal ages is needed before we can conclusively guide the optimal timing and trigger thresholds for RBCT in preterm infants.

Prevention of the anaemia of prematurity

Despite recent advances in neonatal and perinatal medicine, extremely low birth weight infants (ELBW) are at high risk of developing anaemia of prematurity (AOP) requiring packed red blood cell (RBC) transfusions. The benefit of transfusing allogenic RBCs for AOP is a controversial issue, except for disturbances in tissue oxygenation. Although the role of erythropoietin (EPO) in the pathophysiology of AOP is well known, neither early nor late recombinant human EPO therapy alters the number or volume of RBC transfusions. It is also known that one-half of the feto-placental blood volume remains outside the newborn infant's circulation at 30 weeks of gestation if the umbilical cord is clamped immediately. Delayed cord clamping (DCC) and umbilical cord milking (UCM) are the main methods for enhancing placental transfusion. The basic principle of these approaches depends on providing high haemoglobin (Hb) levels to premature infants in the delivery room. The enhancement of placental transfusion clearly results in higher Hb levels at birth, reducing the need for RBC transfusions as well as creating a better haemodynamic status during the initial hours of life. To date, enhancement of placental transfusion in the delivery room by either DCC or UCM seems to be the best preventive measure for AOP. Yet, studies on the associated neurodevelopmental outcomes are insufficient to reach a conclusion. This review summarizes the pathophysiology, treatment and preventative strategies of anaemia of prematurity in light of the current literature.

Placental transfusion strategies in extremely preterm infants: the next piece of the puzzle

Evidence is growing on the potential value of enhancing placental-fetal transfusion at birth, with recent endorsement of the practice by the World Health Organization and American College of Gynecologists. However, these recommendations provide clinicians with little guidance on the optimal practice among infants born extremely premature (<28 weeks gestation) and those requiring immediate resuscitation. The goals of this review are to: 1) provide rationale for better outcomes among extremely preterm infants following delayed cord clamping or umbilical cord "milking" than with immediate cord clamping; 2) describe clinical situations that warrant immediate cord clamping following delivery and explore the controversy regarding optimal cord clamping practice among extremely premature infants, including those requiring immediate resuscitation; 3) discuss the quality of evidence in this subgroup of infants; 4) consider areas for future research, with a focus on characterizing if placental-fetal transfusion affects the magnitude or timing of variables associated with physiological transition. The review provided herein suggests that delayed cord clamping or umbilical cord milking can be applied safely to infants born prior to 28 weeks gestation, but the lack of evidence on the best practice among infants born severely depressed and requiring immediate resuscitation, who comprise a greater proportion of infant deliveries at the lowest gestational ages, is recognized. Future studies using well-defined physiologic outcome measures are needed to understand the role of placental transfusion in premature infants' adaptations to extrauterine life.

Steps for implementing delayed cord clamping in a hospital setting

Background

Delayed umbilical cord clamping (DCC) permits placental-to-newborn transfusion and results in an increased neonatal blood volume at birth. Despite endorsement by numerous medical governing bodies, DCC in preterm newborns has been slow to be adopted into practice. The purpose of this article is to provide a framework to guide medical providers interested in implementing DCC in a hospital setting. A descriptive implementation guideline is presented based on the author’s personal experiences and the steps taken at the University of Washington (UW) to implement DCC in premature newborns <37 weeks’ gestational age. Quality improvement data was obtained to assess compliance with DCC performance over the initial six months following initiation of the treatment protocol in July 2014. An anonymous electronic survey was administered to obstetrical providers in January 2015 to assess DCC policy awareness and adherence.

Results

Important steps to consider regarding implementation of DCC in a hospital settings include applying a multidisciplinary educational approach aimed at motivating potential stakeholders potentially impacted by DCC, addressing safety concerns regarding DCC, and developing a standardized DCC treatment protocol. In the first month following DCC protocol implementation at UW, 79.2% (19/24) of premature newborns admitted to the neonatal intensive care unit received DCC, but compliance decreased over time, with DCC documented in only 40.1% (61/150) of newborns during the 6-month period following implementation. The majority of obstetrician survey respondents (90.9%, 20/22) were aware of the UW DCC policy for preterm deliveries, had performed DCC in the past 6 months (95.5%, 21/22), felt that they had sufficient understanding of the risks and benefits of DCC (90.9%, 20/22) and cited concerns for maternal hemorrhage and the need to resuscitate the baby as the main reasons to perform immediate cord clamping instead of DCC.

Conclusion

Healthcare providers interested in implementing DCC may benefit from a procedural practice plan that includes an assessment of organizational readiness to adopt a DCC protocol, methods to measure and encourage staff compliance, and ways to track outcome data of infants who underwent DCC. Strategies to improve protocol awareness after DCC has been implemented are recommended since compliance may decrease over time.

Impact of cesarean section on placental transfusion and iron-related hematological indices in term neonates: a systematic review and meta-analysis

Evidence suggests that cesarean section is likely associated with a reduced placental transfusion and poor hematological status in neonates. However, clinical studies have reported somewhat inconsistent results. We conducted a systematic review and meta-analysis to examine whether cesarean section affects placental transfusion and iron-related hematological indices. Pubmed, Web of Science, ScienceDirect, and Ovid Databases were searched for relevant studies published before April 9, 2013. Mean differences between cesarean section and vaginal delivery in outcomes of interests (placental residual blood volume; hematocrit level, hemoglobin concentration, and erythrocyte count in cord/peripheral blood) were extracted and pooled using a random effects model. We identified 15 studies (n = 8477) eligible for the meta-analysis. Compared with neonates born vaginally, those born by cesarean section had a higher placental residual blood volume [weighted mean difference (WMD), 8.87 ml; 95% confidence interval (CI), 2.32 ml-15.43 ml]; a lower level of hematocrit (WMD, -2.91%; 95% CI, -4.16% to -1.65%), hemoglobin (WMD, -0.51 g/dL; 95% CI, -0.74 g/dL to -0.27 g/dL) and erythrocyte (WMD, -0.16 × 10(12)/L; 95% CI, -0.30 × 10(12)/L to -0.01 × 10(12)/L). Subgroup analysis showed that the WMD for hematocrit in neonate's peripheral blood (-6.94%; 95% CI, -9.15% to -4.73%) was substantially lower than that in cord blood (-1.75%; 95% CI, -2.82%, -0.68%) (P value for testing subgroup differences <0.001). In conclusion, cesarean section compared with vaginal delivery is associated with a reduced placental transfusion and poor iron-related hematologic indices in both cord and peripheral blood, indicating that neonates delivered by cesarean section might be more likely affected by iron-deficiency anemia in infancy.

Optimal timing of umbilical cord clamping for term and preterm babies

Deferring cord clamping allows blood flow between baby and placenta to continue for a few moments. This often leads to increased neonatal blood volume at birth. It also allows for longer transition to the neonatal circulation. Optimal timing for clamping the cord remains uncertain. This paper discusses the physiology of placental transfusion and presents the evidence from systematic reviews of randomised trials comparing alternative strategies for cord clamping for both term and preterm births. For healthy term infants, deferring cord clamping increases iron stores in infancy. Therefore, a more liberal approach to deferring cord clamping appears to be warranted, provided screening and treatment for jaundice requiring phototherapy is available. For preterm births, although there are few data on the main clinical outcomes, the evidence is promising that deferred cord clamping may be beneficial. For both term and preterm infants there is little information about long term development.

Placental blood transfusion in newborn babies reaches a plateau after 140 s: Further analysis of longitudinal survey of weight change

Objective:

With the introduction of active management of the third stage of labour in the 1960s, it became usual practice to clamp and cut the umbilical cord immediately following birth. The timing of this cord clamping is controversial, as blood may beneficially be transferred to the baby if clamping of the cord is delayed slightly. There is no agreement, however, on how long the delay should be before clamping the cord. This study aimed to establish when blood ceased to flow in the umbilical cord to determine how long to delay clamping of the umbilical cord following delivery of the term newborn to maximise placental transfusion.

Methods:

This observational study collected longitudinal weight measurements set in a hospital labour ward. A total of 26 mothers at term and their singleton babies participated in the study. In this reanalysis, the velocity of weight change over the first minutes of life determined by functional data analysis was estimated.

Results:

We found that the flow velocity in the umbilical cord was on average 0 at 125 s after placing the baby on the scales, which was typically 140 s after birth.

Conclusions:

To maximise placental transfusion, cord clamping should be delayed for at least 140 s following birth of the baby.