Stem cell harvesting at birth is a simple, noninvasive, painless medical procedure lasting between 30 seconds and 2-3 minutes.
After the birth, the umbilical cord is pulsating for a few minutes (usually between 3-5 minutes). When the last pulsation stops the umbilical cord is clamped and cut off from the newborn.
In the blood vessels of umbilical cord and the placenta remains in average 50-60 ml of blood, after the clamping and the cutting of the umbilical cord.
This blood, known as umbilical cord blood, is the primary source of cells usable for blood forming stem cell transplants and for emerging, regenerative medicine field.
Cells usable for transplants contain a small amount of primary blood forming stem cell and many other cells in different stage of maturation belonging mainly to blood cells line, so called progenitors.
But in the common language has been adopted and it is used the “stem cell” term, by which it is understand all the type of cells usable for transplants. Therefore I will adopt it too, in order to simply the text.
There are currently two methods of stem cell harvesting at birth:
- After birth while placenta is still connected to uterus (so called in utero stem cell harvesting at birth) or
- After the delivery of placenta (so called ex utero stem cell harvesting at birth).
Of these two methods, the current clinical experience brings arguments in favor of harvesting before placenta delivery, the risk of contamination of the sample is lower and the volume of blood drawn is higher.
At the time of harvesting in both of these methods the newborn is already detached from the umbilical cord.
After the birth, according to the latest recommendation of American College of Obstetricians and Gynecologists, issued in 2017, doctor waits for at least 30–60 seconds and then only clamp the umbilical cord.
Applying the delayed umbilical cord clamping in vigorous term and preterm newborn appears to be beneficial on the developmental outcomes.
Recent studies have shown that in the first minute after birth about 80 ml of blood is transferred, while in the first 3 minutes the amount reaches up to 100 ml.
It seems that first breaths of the newborn, taken at about 10 seconds after birth, facilitate placental transfusion of blood.
An increase of transferred blood is the source of:
- An improved iron deposit in the first several months, important for a normal cognitive, motor and behavioral development.
- Maternal immunoglobulins transfer to newborn, essentially for the first 6 months until infant’s immune system become mature
- important for tissue and organ repairs
These are even more important in preterm infants, having a higher risk for cellular and tissues injuries, inflammation processes and organ dysfunctions.
Therefore the stem cell harvesting at birth it is recommended to be performed ONLY after passing the 30-60 seconds corresponding to delay umbilical cord clamping.
The stem cell harvesting at birth is a medical procedure which can be applied both in vaginal delivery and in cesarean delivery.
The final decision on the appropriateness of this procedure will be taken by the obstetrician who attends the birth, depending on how it evolves.
In the event of obstetric maternal or infant complications before, during or soon after the newborn delivery, this procedure will not be performed.
Mother’s and infant’s safety comes first.
There are also some special conditions to be taken into consideration.
The stem cell harvesting at birth may be performed if:
- Pregnant is pretreated for Group B streptococcal colonization
- If active genital herpes or HPV lesions present, then collect cord blood only if Cesarean section delivery
- Prolonged rupture of membranes only in the absence of maternal sepsis
The stem cell harvesting at birth is not recommended to be performed if:
- Known maternal history of active hepatitis or HIV or syphilis
- Mother is septic or febrile
- Foul smelling placenta
Stem cell harvesting at birth is done in sterile collection kits, consisting of a blood collection bag attached to a tubing system having at the end 2 catheters/needles necessary for puncture of the umbilical vein.
Attached to the tubing there is a small anticoagulant container that will be poured into the harvest bag after the procedure is completed.
The primary objective of each stem cell harvesting at birth is to ensure the collection of the maximum umbilical cord blood.
Thus it is optimized the stem cell harvesting at birth.
The volume of umbilical cord blood available for harvest ranges from 20 to 200 m, in average is about 60-70 ml.
The total number of cells usable for transplants could vary from one birth to another, even for the same volume of harvested umbilical cord blood.
Each cord blood unit is characterized by quantitative parameters relevant from a transplant perspective:
- Number of cells usable for transplants, known as total nucleated cells – TNC and
- The number of CD 34 + cells, cells in intermediate stage of maturation belonging to blood forming)
- Colony forming unit, usually assessed at the time of transplant
And by quality parameters:
- Cord blood unit sterility
- Viability of cord blood unit cells
- Tests result for certain maternal infectious diseases
In terms of standard indications for blood forming stem cell transplantation, in general, the quantitative parameters of the cord blood unit are appropriate for pediatric or adolescent patients.
Currently, worldwide have been performed more than 40 000 cord blood unit transplants for standard indications.
Regenerative medicine according to the latest results of researches is predicted to be a new promising area of new therapeutic application of cord blood units.