In cases where paternity testing needs to be completed as soon after birth as possible, the umbilical cord blood can be used in blood DNA paternity testing.
The father will need to provide a sample, in addition to the baby's sample taken at birth. The fathers sample will have the DNA pulled from the sample as will the sample taken from the cord blood. After the strands of DNA are extracted, the loci (or DNA points) are matched. Most professional DNA paternity testing facilities will use 16 loci points to match the DNA from the cord blood sample to the DNA from the father's sample. The more loci matches, the more likely the suspected father is the biological father of the child.
DNA testing is by far more accurate than other forms of paternity testing. The DNA test is considered 100% accurate in excluding a suspected father from biological parent status and 99.99% accurate in establishing loci matches between the baby and the father. This means the father tested would be 99.99% sure that he is the biological father of the baby tested.
Cord blood paternity testing is more expensive than postnatal testing but less expensive than prenatal testing. No matter how the sample is extracted, the DNA testing results will still be the same. So, the cord blood will be just as accurate as the cheek swab and the hair test as long as DNA testing and the same number of loci are used to establish the paternal parent.