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.     

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.     

Placental transfusion: umbilical cord clamping and preterm infants.

OBJECTIVE: To investigate the clinical effects of early versus late cord clamping in preterm infants. STUDY DESIGN: A total of 32 premature infants were prospectively randomized. The following parameters were measured: Initial spun hematocrit (Hct), hemoglobin (Hgb), red blood cell (RBC) counts, frequency of blood transfusions, peak serum bilirubin, mean blood pressure (MBP), oxygen index, intraventricular hemorrhage, and significant patent ductus arteriosus (PDA). RESULTS: Over the 4-week study period, the delayed cord clamping (DCC) group exhibited a decrease in the frequency of blood transfusion (p < 0.001) and also a decrease in albumin transfusions over the first 24 hours (p < 0.03). MBP in the first 4 hours was higher in the DCC group (p < 0.01), and there were statistically significant increases in Hct (21%), Hgb (23%), and RBC count (21%) compared with the early cord clamping group. The risks of patent ductus arteriosus, hyperbilirubinemia, or intraventricular hemorrhage were similar in both groups. Late clamping of the umbilical cord had little or no effect on the oxygen index. CONCLUSION: DCC significantly reduced the requirement for blood and albumin transfusion. It also increased the initial Hct, RBC count, Hgb levels, and MBP.     

Effect of delayed umbilical cord clamping on blood gas analysis

Objective

To ascertain if there are differences in umbilical cord blood gas analysis between immediate and delayed cord clamping.

Study design

In a prospective observational study on 60 vaginally delivered healthy term newborns, we sampled umbilical cord blood immediately after delivery and at the time umbilical cord pulsation spontaneously ceased.

Results

There were significant decreases in pH, oxygen saturation (sO₂), glycemia, oxygen content (ctO₂), bicarbonate (HCO₃⁻) and base excess (BE). Lactate and PCO₂$P_{{\text{CO}}_2}$ increased. Delayed cord clamping pH correlated with immediate cord clamping pH, PO₂$P_{{\text{O}}_2}$, ctHb, sO₂ and time (r² = 0.77, p < 0.000). Delayed cord clamping lactate was associated with immediate cord clamping lactate and time (r² = 0.83, p < 0.000). Delayed BE was associated with previous pH, lactate, glycemia, ctHb and time (r² = 0.83, p < 0.000).

Conclusions

Delayed cord clamping alters acid–base parameters and lactate values compared to immediate cord clamping. Those variations depend mainly on time, prior pH and lactate.     

A case of umbilical cord hemangioma: Doppler studies and review of the literature

Hemangiomas of the umbilical cord are extremely rare benign vascular tumors, not always detected prenatally. They have been associated with increased alpha-fetoprotein (AFP), hydramnios, congenital anomalies, and increased perinatal mortality. Impaired umbilical circulation has been proposed as the predisposing factor for fetal compromise. We report a case of an antenatally detected umbilical cord hemangioma with one artery crossing the tumor, and we reviewed the literature. Close surveillance with Doppler flow studies of the umbilical vessels were carried out throughout the pregnancy. All indices were normal, except from the intra-tumoral part of the umbilical artery under discussion that showed increasing resistance from 32 weeks onwards.     

Challenging current practice: the evidence behind the timing of cord clamping

Immediate clamping of the umbilical cord is an intervention that has developed over the last century as birth moved into the hospital setting (Mercer 2001). Whilst active management in the third stage of labour is widely practised, midwives are encouraged to re-evaluate their management strategies during this stage, since immediate clamping of the umbilical cord interferes with the physiological process of normal childbirth and should be justified (Begley et al 2010; Gyte 1994). Exploration of the physiological and research based evidence would indicate that the practice of umbilical cord clamping at birth needs to be raised with the whole multi-disciplinary team in order to influence practice (Anderson 2005; ICM 2003).     

Early versus delayed cord clamping in term and preterm births: a review

The optimal timing for cord clamping, early versus delayed, in the third stage of labour is a controversial subject. Issues surrounding the timing of cord clamping include gestational age and maternal and neonatal considerations. Delayed cord clamping (DCC) has been shown to increase placental transfusion, leading to an increase in neonatal blood volume at birth of approximately 30%. In the term infant, although this may result in an increase in iron stores, thereby decreasing the risk of anemia, it may adversely increase the risk of jaundice and the need for phototherapy. In the preterm infant, DCC (or even milking of the cord) decreases the need for blood transfusions for anemia, the number of such transfusions, and the risks of intraventricular hemorrhage and late-onset sepsis. Advantages of DCC also include a reduction in alloimmunization in Rh-negative women, although this advantage is theoretical and unproven. We searched multiple databases including PubMed Clinical Queries, Trip Database, Cochrane Systematic Reviews, and UpToDate, as well as published guidelines from the Society of Obstetricians and Gynaecologists of Canada, the American Congress of Obstetricians and Gynecologists, and the Royal College of Obstetricians and Gynaecologists. We preferentially selected systematic reviews and randomized controlled trials for this literature review. Overall, the available evidence appears to suggest that DCC is likely to result in better neonatal outcomes in both term and preterm infants, even in areas where neonatal iron deficiency anemia is rare. However, there is insufficient evidence to date to support a recommendation to delay cord clamping in non-vigorous infants requiring resuscitation.     

Rupture of umbilical cord chorioangioma, intraamniotic hemorrhage and fetal death: report of a case and review of the literature

The umbilical cord is exposed to a great variety of injuries and events throughout the pregnancy whose origin may be either structural, mechanical, hamartomatous or infectious (1). Some of these alterations unquestionably interfere directly with the fetoplacental circulation either blocking it or creating severe haemorrhage as a result of laceration or tumor rupture. True tumors of the umbilical cord interfere directly with the fetal development. Two true tumors of the umbilical cord are described in this paper: chorangioma and teratoma. Chorangioma is a benign tumor, but has a very high rate of rate of perinatal mortality. Its frequency is rare, reporting in literature it presence of 1:3500 pregnancies. Our objective was to review world-wide literature and to report a case of fetal death by chorangioma of umbilical cord.     

Spinal cord injury in newborns from use of umbilical artery catheters: report of two cases and a review of the literature

Umbilical artery catheter use in sick newborns has been associated with infarction of major organs such as the intestine and kidneys; spinal cord infarction has also been reported but is rare. We report two cases of spinal cord infarction and review the six others in the literature for preventable or predisposing conditions. Infusion of blood and hypertonic solutions, shock, and high position of the catheter tip were associated with infarction of the anterior spinal cord in these infants.     

Current obstetrical practice and umbilical cord prolapse

The aim of this study was to assess the contribution of current obstetrical practice to the occurrence and complications of umbilical cord prolapse. Maternal and neonatal charts of 87 pregnancies complicated by true umbilical cord prolapse during a 5-year period were reviewed. Twin gestation and noncephalic presentations were common features (14 and 41%, respectively). Eighty-nine percent (77) of infants were delivered by cesarean section of which 29% were classical and 88% were primary. The mean gestational age at delivery was 34.0 +/- 6.0 weeks, and the mean birth weight was 2318 +/- 1159 g. Obstetrical intervention preceded 41 (47%) cases (the obstetrical intervention group): amniotomy (9), scalp electrode application (4), intrauterine pressure catheter insertion (6), attempted external cephalic version (7), expectant management of preterm premature rupture of membranes (14), manual rotation of the fetal head (1), and amnioreduction (1). There were 11 perinatal deaths. Thirty-three percent of the infants (32) had a 5-min Apgar score < 7 and 34% had a cord pH < 7.20. Neonatal seizures, intracerebral hemorrhage, necrotizing enterocolitis, hyaline membrane disease, persistent fetal circulation, sepsis, assisted ventilation, and perinatal mortality were comparable in the "obstetrical intervention" and "no-intervention" groups. Most of the neonatal complications occurred in infants < 32 weeks' gestation. We conclude that obstetrical intervention contributes to 47% of umbilical cord prolapse cases; however, it does not increase the associated perinatal morbidity and mortality.     

The umbilical coiling index, a review of the literature.

Our aim was to review the literature on umbilical cord coiling. Relevant articles in English published between 1966 and 2003 were retrieved by a Medline search and cross-referencing. The normal umbilical cord coiling index (UCI) is 0.17 (+/- 0.009) spirals completed per cm. Abnormal cord coiling, i.e. UCI <10th centile (<0.07) or >90th centile (>0.30) is associated with adverse pregnancy outcome. Hypocoiling of the cord is associated with increased incidence of fetal demise, intrapartum fetal heart rate decelerations, operative delivery for fetal distress, anatomic-karyotypic abnormalities and chorio-amnionitis. Hypercoiling of the cord is associated with increased incidence of fetal growth restriction, intrapartum fetal heart rate decelerations, vascular thrombosis and cord stenosis. It is not clear whether abnormal coiling is actually a cause of pathology, or merely one of the sequelae, or both. We discuss the theories involving the cause of cord coiling, and the consequences of the degree of cord coiling on blood flow through the umbilical vessels. In the future ultrasonographic evaluation of the umbilical cord and the UCI may become an integral part of fetal assessment in high-risk pregnancies.     

Umbilical cord rupture: a case report and review of literature

The umbilical cord acts as a mechanical conduit between the fetus and placenta, allowing movement of water and nutrient substances between the fetal circulation and the amniotic fluid. Complications can occur antenatally or intranatally and are usually acute events that require immediate delivery to prevent intrauterine death. Even though the majority of the cord complications are unpreventable, significant improvement in perinatal mortality and morbidity can be achieved if such an event can be predicted. Umbilical cord rupture is not uncommon, but significantly underreported. We present an unusual cause of umbilical cord rupture and a review of literature.     

Changing practice: physiological cord clamping

Every baby deserves the best start to life. Receiving the full quota of blood from the placenta directly after birth has profound short and long-term benefits for the baby; these have been extensively researched and documented. This article discusses a student midwife's experience of participating in reviewing third stage guidelines to incorporate this growing evidence base into clinical practice within a large London NHS Trust. A new local guideline (unpublished) recommends every baby (where clinically possible) has the opportunity to benefit from 'physiological cord clamping'. The aim of the article is to inspire midwives and student midwives to become involved with similar activities within their own trusts.