Doctor Tham Thi Thu Nga, Head of Lab at the Stem Cell Center, Tam Anh General Hospital System, explains that the fundamental process for collecting, processing, and storing umbilical cord blood stem cells is largely similar for both twins and singletons. Both adhere to strict technical standards. The key distinction for twins, however, lies in precise sample identification and management. Each baby's sample must be accurately marked and labeled during collection to prevent mix-ups throughout processing and storage.

A Stem Cell Center staff member collects stem cells for twins at Tam Anh General Hospital, Ho Chi Minh City. *Illustration: Nguyet Nhi*

For twins, the volume of umbilical cord blood collected can often be lower compared to singletons. This is typically due to each fetus having a lower birth weight or a shorter umbilical cord. Despite this, in many instances, the sample volume still meets the standards for storage and can be used when needed.

Regarding genetic factors, fraternal twins are two genetically distinct individuals. Therefore, it is mandatory to store each sample separately to facilitate personalized treatment later.

For identical twins, even with a high degree of genetic similarity, each child may encounter different health issues in the future. Consequently, separate storage for each baby is still recommended to increase options for suitable treatment.

Technically, current sample processing and preservation systems are designed for standard volumes. If samples are combined and exceed the permissible capacity, the excess portion may need to be discarded, leading to waste. Manual mixing of samples also increases the risk of contamination, affecting long-term storage quality.

Theoretically, other options might be considered for identical twins. However, in clinical practice, experts consistently recommend separate storage of umbilical cord stem cells for each twin to ensure safety, accuracy, and optimal effectiveness for future applications.

Doctor Tham Thi Thu Nga

Head of Lab, Stem Cell Center

Tam Anh General Hospital System