Overview & Description
Cord blood tests are done on a blood sample collected fromthe umbilical cord of a newborn. A variety of tests may be done on thisblood sample. The type of test done depends on whether there were anyproblems during the pregnancyor during labor and birth.
Who is a candidate for the test?
A cord blood test is only done on newborns. Most hospitalsroutinely collect a cord blood sample when a baby is born.
How is the test performed?
Once the baby is born, the umbilical cord is clamped and cut.A second clamp is placed about 8 to 10 inches away from the first clamp.The cord is cut there as well. The blood sample is taken from this sectionof the cord. No pain is felt by the mother or baby.
Preparation & Expectations
What is involved in preparation for the test?
There is no special preparation for a cord blood test.
Results and Values
What do the test results mean?
The following tests may be performed on the cord blood:
Blood gases,to evaluate the oxygen and carbon dioxide levels in the newborn baby
Respiratory status, including pH, pCO2, pO2. pH tells how the lungs arefunctioning in using oxygen and releasing carbon dioxide. pO2 andpCO2 measure the pressure levels of oxygen and carbon dioxide in the baby.
Complete blood count, calledCBC
Platelet count, which is one measure of the blood’s clotting ability
Blood cultures for aerobicand anaerobicbacteria to rule out infection
Test results will be within a healthy range for some babies. For others,abnormal results suggest certain health problems or other issues:
A low pH (less than 7.25) indicates high levels of acid in the infant’sbloodstream. This may occur if the mother or baby does not get enoughoxygen during labor. It may also happen if the umbilical cord becomescompressed during delivery.
A positive blood culturemay show abnormal bacteria in the mother or infant.
A high blood glucoselevel may be present if the mother hasdiabetes.If so, the baby may have a dramatic drop in his or her blood glucose level afterbirth. This condition is called hypoglycemia.
A high bilirubin level can be a sign of several health issues,such as:
jaundicein the mother. This is a yellowing of the skin caused by too much of the liverprotein called bilirubin in the blood.
Rh incompatibility,which is a problem with blood compatibility between the baby and the mother
Dubin-Johnson syndrome, a condition in which a collection of bilirubin inthe baby’s liver cells causes jaundice
sulfa medicines taken by the mother during pregnancy
toxoplasmosis,an infection that causes destructive lesions of the nervous system
rubella,also known as German measles, a disease that may cause birth defects ina baby if the mother had it during the first 2 to 3 months of pregnancy
hepatitis,an inflammation in the baby’s liver
cytomegalovirus,known as CMV, an infection that may cause symptoms such asfever,lethargy, and loss of appetitein the baby
Article type: xmedgeneral