Home About AllHealth Website Sitemap Contact Us
All Health 
You are here: Home > Old Medical Ref > Old Test Finder > cord blood sampling


cord blood tests

Alternative Names
cord blood test, cord blood sampling

Cord blood tests are done on a blood sample collected from the umbilical cord of a newborn. A variety of tests may be done on this blood sample. The type of test done depends on whether there were any problems during the pregnancy or during labour and birth.

Who is a candidate for the test?
A cord blood test is only done on newborns. Most hospitals routinely 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 section of the cord. No pain is felt by the mother or baby.

What is involved in preparation for the test?
There is no special preparation for a cord blood test.

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
  • cord pH
  • respiratory status (pH, pCO2, pO2). pH tells how the lungs are functioning in using oxygen and releasing carbon dioxide. pO2 and pCO2 tell what the pressure levels are of oxygen and carbon dioxide in the baby.
  • full blood count, or FBC
  • platelet count, which gives an indication of the blood's clotting ability
  • blood type
  • blood cultures for aerobic and anaerobic bacteria to rule out infection
  • bilirubin
  • blood glucose
Test results will be normal for some babies. For others, abnormal results suggest certain health problems or other issues.
  • A low pH (pH less than 7.25) indicates high levels of acid in the infant's bloodstream. This may occur if the mother or baby does not get enough oxygen during labour. It may also happen if the umbilical cord becomes compressed during delivery.
  • A positive blood culture may show abnormal bacteria in the mother or infant.
  • A high glucose, or blood sugar, level may be present if the mother has diabetes. If so, the baby may have a dramatic drop in his or her blood sugar level after the birth. This condition is called hypoglycaemia.
High bilirubin levels can be a sign of several health issues, such as:
  • jaundice in the mother. This is a yellowing of the skin caused by too much of the liver protein 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 in the baby's liver cells causes jaundice
  • sulphur medications taken by the mother during pregnancy
  • toxoplasmosis, an infection that causes destructive lesions of the nervous system
  • rubella, a disease that may cause birth defects in a baby if the mother had it during the first 2 to 3 months of pregnancy
  • hepatitis, an inflammation in the baby's liver
  • cytomegalovirus (CMV), an infection that may cause symptoms such as fever, lethargy, and loss of appetite in the baby
Reviewer: HealthAnswers Australia Medical Review Panel
Editor: Dr David Taylor, Chief Medical Officer HealthAnswers Australia
Last Updated: 1/10/2001
Potential conflict of interest information for reviewers available on request

This website and article is not a substitute for independent professional advice. Nothing contained in this website is intended to be used as medical advice and it is not intended to be used to diagnose, treat, cure or prevent any disease, nor should it be used for therapeutic purposes or as a substitute for your own health professional's advice.  All Health and any associated parties do not accept any liability for any injury, loss or damage incurred by use of or reliance on the information.


Back Email a Friend View Printable Version Bookmark This Page


eknowhow | The World's Best Websites
    Privacy Policy and Disclaimer