Current Practices in
Cord Blood Collection
Delayed Cord Clamping
When a baby is delivered, the umbilical cord will be clamped and cut, typically within seconds of birth. Delayed cord clamping refers to the practice of delaying clamping and cutting of the umbilical cord for about 1 to 3 minutes to allow more placental blood to flow through the cord to the baby.
Even without delayed cord clamping, as little as 1 out of 4 cord blood units were banked . The rest were discarded, mostly due to insufficient quantity of cord blood collected to meet requirements for public banking and transplantation .
Study have shown that with delayed cord clamping of more than 60 seconds, the number of bankable units has decreased by half .
Click here to learn more about Delayed Cord Clamping and its impact on the quality of cord blood units collected.
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Short Collection Window
Currently, cord blood is collected either before the placenta is delivered (in-utero) or after the placenta is delivered (ex-utero). For in-utero collection, the obstetrician will puncture the umbilical cord and hold the needle in place for 2 – 3 minutes to allow blood to flow into the blood bag.
The obstetrician is often under time pressure to perform other obstetric processes which may lead to ending the collection before the optimal amount of cord blood is collected. As a result, the in-utero collection procedure does not maximize the volume of the blood collected.
The short collection window of the in-utero procedure may be a significant contributing factor to the prevalent issue occurring to many public cord blood banks: A large proportion of cord blood units collected have insufficient quantity of cord blood for banking and are disposed.
Interruption to Obstetric Workflow
After the baby is born, obstetricians will attend to any immediate bleeding and see to the delivery of placenta. Active management of the third stage of labor may be performed with measures such as cord traction and uterotonic administration.
In-utero collection using conventional blood bags delays such obstetric practices for 2 – 3 minutes. This may lead to increased maternal bleeding and place the mother at higher risk of PPH .
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Needle Stick Injuries
With conventional blood bags, the needle is exposed throughout the whole collection process. The obstetrician has to insert the needle into the umbilical vein and hold it in place. The obstetrician may milk the umbilical cord towards the needle to aid blood collection. The exposed needle puts the obstetrician at risk of needle stick injuries.
Difficulty Assessing Optimal Collection End Point
The duration of in-utero collection depends on the obstetrician’s judgement on the optimal collection end point. The obstetrician will end collection based on factors such as cessation of pulse, level of engorgement of vein and pre-fixed collection timings. As a result, the obstetrician may end collection before the maximum amount of cord blood could be collected.
References
1 Lauber, S., Latta, M., Klüter, H., & Müller-Steinhardt, M. (2010). The Mannheim Cord Blood Bank: Experiences and Perspectives for the Future. Transfusion Medicine and Hemotherapy, 37(2), 90–97. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2914417/
2 Allan, D. S. et al. (2016). Delayed clamping of the umbilical cord after delivery and implications for public cord blood banking. Transfusion, 56, 662–665. https://www.ncbi.nlm.nih.gov/pubmed/26585667
3 Royal College of Obstetricians and Gynaecologists (2006). Umbilical Cord Blood Banking Scientific Impact Paper No. 2. https://www.rcog.org.uk/globalassets/documents/guidelines/scientific-impact-papers/sip_2.pdf