Delayed cord clamping has been linked to health benefits for both mother and baby. But what does this mean for umbilical cord blood collection and transplantation?
Stem Cell Scientists from Biovault and University College London, as well as the Parents' Guide to Cord Blood Foundation, believe that it is. Here they review the challenge and offer their expert insights into optimum umbilical cord blood storage with minimal compromise.
Delayed umbilical cord clamping: definition
Delayed umbilical cord clamping is defined as the "interruption of the blood supply between cord and infant after more than one minute postpartum" by Lindsey Parker et al in their paper published this week by BioInsights.¹ This follows The World Health Organisation (WHO) who recommend delayed clamping, "not earlier than 1 min after birth... for improved maternal and infant health and nutrition outcomes."²
Benefits of delayed cord clamping for full-term babies
Delayed clamping allows blood to flow between the placenta and the newborn baby after birth for a period of 1-3 minutes. This prolonged access to blood from the placenta and umbilical cord may increase the baby's iron stores for up to six months, reducing the risk of iron deficiency anaemia.
In randomised controlled trials:
- scientists found no difference in mortality or admission to intensive care between those with delayed or early umbilical cord clamping (1675 full-term infants)
- studies of 954 infants found no significant difference between the rates of anaemia in full-term babies at 3-6 months of age with delayed or early clamping
- a higher incidence of iron-deficiency was associated with early clamping in studies of 1152 infants at 3-6 months
WHO notes that these findings are particularly relevant for "infants living in low-resource settings with reduced access to iron-rich foods."²
Benefits of delayed cord clamping for pre-term babies
In studies of 668 pre-term babies, no difference was found in the risk of infant mortality. However, babies born pre-term benefitted most from delayed clamping, with a 39% reduction in the need for blood transfusion for anaemia or low blood pressure.²
Maternal benefits of delayed cord clamping
In a recently updated review of over 2000 women, no significant differences were found in the rates of severe postpartum haemorrhage ( >100ml) or postpartum haemorrhage (>500ml) between groups with early or delayed clamping times.²
Umbilical cord blood banking: the benefits
Umbilical cord blood is a source of haematopoietic stem cells (HSCs). The transplantation of HSCs is an established treatment for leukaemias, lymphomas, multiple sclerosis, metabolic diseases and numerous disorders of blood cell proliferation, including sickle cell disease and Fanconi's anaemia.
Umbilical cord blood can be stored and used to treat the donor child or any other compatible patient. In the case of privately stored blood, HSCs may be used to treat a sibling or other family member with a blood cancer or disorder.
Umbilical cord blood HSCs offer an alternative to peripheral blood and bone marrow stem cells and have advantages over both. The collection of cord blood is quick, non-invasive and painless, and the HSCs are generally healthier and in higher numbers than those sourced from older donors. Since the first transplant of umbilical cord blood HSCs in 1988, it is estimated that over 35,000 umbilical cord blood transplants have been performed worldwide.
Infant and maternal health: weighing up the options
In a recent study, The Parents' Guide to Cord Blood Foundation examined the effect of delayed cord clamping on the "volume and pre-processed total nucleated cell count based on the length of time clamping is delayed." The findings from this study were presented at the 15th International Cord Blood Symposium, and published in the journal Transfusion.³
Over a 4 month period, data collection cards for more than 2,000 families were completed by medical professionals who performed cord blood collections for ViaCord. On the cards, medical professionals indicated if delayed clamping was performed, as well as the duration of the delay. These were categorised as: no delay, yes <1 minute, yes 1-3 minutes, yes > 3 minutes and yes time unknown.
The cord blood collections were then measured for initial cord blood volume and pre-processed TNC counts. The data collected over the four months were averaged to evaluate the impact delayed clamping had on the cord blood collections. Below are the findings.
Whilst both cord blood volumes and pre-processed TNT counts decline as delay increases, the results show that delayed cord clamping and cord blood banking can coexist. The Parents' Guide to Cord Blood Foundation suggests that "parents planning to collect and bank their cord blood need to discuss and weigh the value of optimising cord blood collection versus potential benefits of delayed cord clamping with their medical professional. For example, if a parent knows that the cord blood they’ll be collecting from their baby will be used in a sibling donor situation then delayed clamping should be avoided."
¹ EXPERT INSIGHT: Advances and challenges in umbilical cord blood and tissue bioprocessing: procurement and storage, Lindsey Parker, Shaun Mansfield, Kate Sneddon, Ben Charles and Qasim A. Rafiq (August 2017)