How Can I Determine which Processing Method Is Best?
1. Collection: There are two options for harvesting blood from the umbilical cord: the gravity method and the syringe method.
In the syringe method, the syringe is inserted into the umbilical vein to draw the blood out. It may be necessary to change syringes mid-procedure or add anticoagulant to the syringe, resulting in extra steps for your health care provider. For this reason, the gravity bag is the preferred method among many doctors and midwives.
In the gravity bag method, a needle is inserted into the umbilical vein and gravity pulls the remaining blood from the cord into the collection bag. Both methods are performed after the cord has been clamped and cut and your baby has been safely removed from the birthing area. Neither method should pose a risk for mother or baby, nor will it interfere with bonding after your baby is born.
2. Processing: Cord blood is only viable for 72 hours after it is collected, so it is important to work with a blood lab that can receive umbilical cord blood for processing and storage 24 hours a day. Since it is not the volume of blood collected, but the number of cells in the sample, it is important the cord blood arrives at the lab quickly and without being exposed to extreme temperatures. Once it arrives at the lab, the cord blood should be tested for bacterial contamination and infectious diseases.
The cord blood should be processed the same day it arrives at the lab, in a closed and sterile environment that optimizes the number of viable cells in your baby's sample.
3. Storage: After processing, cord blood can be stored in either liquid nitrogen or vapor nitrogen.
Liquid Nitrogen uses more nitrogen, but has been shown to keep cord blood at a constant temperature. Tests have also confirmed long-term viability of cells stored in liquid nitrogen. Unfortunately, it has also been proven that there is a chance that infectious diseases can leak between samples stored in liquid nitrogen.
Vapor nitrogen is less expensive, but unlike liquid nitrogen, the temperature inside of the tank can vary. However, vapor nitrogen has been shown to be a safer option for samples that test positive for infectious diseases and have been relegated to a quarantine tank because there is less of a chance that a disease will leak from one bag and contaminate another. And unlike liquid nitrogen, there are no studies to date on the long-term viability of samples stored in vapor nitrogen.