We recommend that cord blood/ cord tissue is banked separately for each child in the case of twins or triplets, however individual cases can be discussed with our Medical Director.
Non-identical twins and non-identical triplets are conceived from different eggs and sperm and are no more alike than siblings born at separate times. The chance of a tissue type (HLA match) between siblings is 25%. In these cases, it is advised to store for each baby as their tissue types are different. Having two units stored increases the likelihood of a useful match between family members and it is possible to combine smaller units should siblings be a match to ensure an adequate stem cell yield for transplantation if ever needed.
For identical twins or rarely identical triplets the fertilized egg divides at an early stage of development and the babies will have the same genetic information. However even in these cases, minor genetic changes may occur after conception and during foetal development. While identical twins are genetically identical, small genetic differences may exist at varying stages of development, causing a low but present risk of differences in disease profiles. For example, one twin may develop leukaemia or diabetes and the other does not.
However, if you request only one collection for cord blood and tissue for identical twins, it is possible to do so after discussing this with our Medical Director. Each case should be discussed with the Medical Director and your obstetrician and the implications of this explained to them. The obstetrician must be sure that this is a case of identical twins for this to be considered.
Either a single collection can be done from one twin with the option to use the unit for the other twin should the need arise OR cord blood can be collected from each umbilical cord (in the case of a single placenta) and combined in one bag. This will lead to a situation of two genetically identical donors for a single unit and hence we recommend that in these cases the unit should be used for syngeneic transplant (i.e. a stem cell transplant only between the identical twins) and possibly not for other siblings. However, should one baby develop a genetic disorder requiring a transplant and the blood is combined, the transplant doctor may decide not to use the cord blood stem cells as they may contain the same genetic problem.
Cord tissue does not require as stringent HLA matching as cord blood so it is possible to only store one umbilical cord tissue unit for both babies.
Please note that collections for any multiple pregnancy has a higher risk of a lower volume with lower cell counts. This is because multiple pregnancies can often be premature, with smaller babies with lower birth weights and smaller placentas. In the case of emergencies where the mother’s health or that is of the babies is of utmost importance, the doctor may decide to abandon the cord blood collection procedure and safely deliver the babies.