By Jean Balchin 01/03/2018

Babies – both premature and full-term – who do not require respiratory support may benefit from leaving their umbilical cord unclamped for at least 60 seconds after birth, according to the authors of a Perspective published recently by the Medical Journal of Australia.

Umbilical Cord

In placental mammals, there exists an umbilical cord, which acts as a conduit between the developing embryo/fetus and the placenta. In humans, the umbilical cord normally contains two arteries and one vein, contained within a substance called Wharton’s jelly. The umbilical cord supplies the fetus with oxygenated, and nutrient-rich blood from the placenta, while also conveying de-oxygenated, nutrient depleted blood from the fetal heart, through the umbilical arteries, back to the placenta.

Cord Clamping

Much debate has occurred recently around the topic of umbilical cord clamping, after the publication of a systematic review and meta-analysis, published in the American Journal of Obstetrics and Gynaecology earlier in 2018. This meta-analysis found that delayed cord clamping (DCC) was recommended for both full-term and pre-term babies, based on results from the Australian Placental Transfusion Study. Until this meta-analysis was conducted, the evidence for benefit from DCC in pre-term babies had been “weak” and “low quality”.

Associate Professor Graeme Polglase, from the Hudson Institute of Medical Research in Melbourne, and Associate Professor Michael Stark, from the Robinson Research Institute at the University of Adelaide,  argued that evidence for DCC was now stronger for babies who were “vigorous and making breathing efforts”. However, they said that there was still uncertainty about DCC in more vulnerable subgroups:

“The critical aspect moving forward is to determine whether DCC is beneficial or harmful to subgroups. If the umbilical cord or placenta is compromised, then there may not be any benefit in DCC and it may potentially be harmful. Similarly, infants born with asphyxia, atony or sepsis may not benefit from DCC if it means delay of respiratory support.”

“Future studies must focus on whether the pathophysiology of the newborn should be guiding the timing of cord clamping or additional interventions before cord clamping, such as stimulation, respiratory support or caffeine administration.

“This personalised approach to medicine in the delivery room may show the considerable benefits of DCC in particular subgroups, and would thus alleviate clinicians’ fears for delaying cord clamping for up to 60 seconds, would identify optimal physiological markers rather than an arbitrary time to clamp the cord, and would also identify populations in which interventions such as initiating respiratory support will take greater priority than umbilical cord management.”

According to the American College of Obstetricians and Gynaecologists’ Committee on Obstetric Practice, in term infants, delaying the clamping of an umbilical cord increases the baby’s haemoglobin levels at birth and improves iron stores in the first several months of life. This may have a favourable effect on the child’s developmental outcomes.

Newborn child, seconds after birth, crying. The umbilical cord has not yet been cut. Wikimedia Commons.

With preterm infants, delaying the umbilical cord clamping is also associated with significant neonatal benefits, such as improved transitional circulation, better establishment of red blood cell volume, decreased need for blood transfusion, and lower incidence of necrotising enterocolitis and intraventricular haemorrhage.

Thus the American College of Obstetricians and Gynaecologists recommends a delay in umbilical cord clamping in vigorous term and preterm infants for at least 30–60 seconds after birth. Delayed umbilical cord clamping does not increase the risk of postpartum haemorrhage.

According to the aforementioned College, there is a small increase in the incidence of jaundice that requires phototherapy in term infants undergoing delayed umbilical cord clamping. Consequently, obstetrician–gynaecologists and other obstetric care providers adopting delayed umbilical cord clamping in term infants should ensure that mechanisms are in place to monitor and treat neonatal jaundice.

The editorial may be read here.

Image: Photo by Echo Grid on Unsplash