What is Percutaneous Umbilical Cord Blood Sampling

Percutaneous umbilical cord blood sampling (cordocentesis) is a diagnostic test. For this procedure, a small amount of blood is taken from the umbilical cord (fetal blood sample) and examined for certain blood disorders and problems in the chromosomes of the unborn child (fetal chromosome abnormalities). It is usually done after the 18th week of pregnancy.

This test may be used to diagnose these conditions in the unborn baby (fetus):

• Infections, including those caused by:
  • A virus, such as rubella.
  • A parasite, such as toxoplasmosis.
  • Bacteria.
• Birth defects.
• Blood problems, such as anemia.
• Bleeding disorders, such as:
  • Hemophilia A or B.
  • Von Willebrand disease.

Tell a health care provider about:

• Any allergies you have.
• All medicines you are taking, including vitamins, herbs, eye drops, creams, and over-the-counter medicines.
• Any blood disorders you have.
• Any problems you or family members have had with anesthetic medicines.
• Any surgeries you have had.
• Any medical conditions you have.
• Any complications you have had with your pregnancy, such as bleeding or contractions.

What are the risks?

Generally, this is a safe procedure. However, problems may occur, including:

• Bleeding of the fetus. This may occur in the area where the needle was inserted to take the sample. If this problem occurs, the fetus may need to receive blood from a donor (fetal blood transfusion).
• Blood clot in the umbilical cord.
• A small number of fetal blood cells getting into the mother’s blood (fetal-maternal bleeding).
• Infection of the uterus, the fetus, or the fluid-filled sac that surrounds the fetus (amniotic sac). Infection of the amniotic sac is called amnionitis.
• A drop in the heartbeat of the fetus. This is usually a temporary condition, but if it does not go away, an emergency cesarean delivery may be needed.
• Breaking of water before the due date (premature rupture of membranes).
• Loss of the baby (miscarriage).

What happens before the procedure?

Ask your health care provider whether you need to take any actions to prepare for this procedure. In general:

• Drink enough fluid to keep your urine pale yellow.
• Plan to have someone take you home from the hospital or clinic.

What happens during the procedure?

• To lower your risk of infection:
  • Your health care team will wash or sanitize their hands.
  • Your skin will be washed with soap.
  • A solution to help prevent infection will be applied to your abdomen. Do not touch the area where the solution was applied until after the procedure.
• You will have a blood sample taken. This sample will be compared with the fetal blood sample.
• You will be asked to lie down on an exam table.
• An IV will be inserted into one of your veins.
• You will be given one or more of the following:
  • Antibiotic medicine to help lower your risk of infection of the uterus.
  • A medicine to numb the area (local anesthetic). It is normal to have some cramping while the procedure is being performed, even after getting this medicine. This cramping is temporary.
• An ultrasound will be done during the procedure to determine the exact position of your baby and the umbilical cord.
• A needle (syringe) will be inserted through your skin and into the umbilical cord to take a small amount of blood.
• The needle will be removed.
• The needle insertion site will be covered with a bandage (dressing).
• The umbilical cord blood sample will be sent for testing.

The procedure may vary among health care providers and hospitals.

What happens after the procedure?

• Your health care provider will monitor you and your baby to make sure there are no problems before you go home.
• If your blood is Rh negative, you may need a Rho (D) immune globulin shot to help prevent complications from the test. Ask your health care provider if you need to have this shot.
• Your health care provider may tell you to rest for the remainder of the day.
• It is up to you to get the results of your procedure. Ask your health care provider, or the department that is doing the procedure, when your results will be ready.

Summary

• Percutaneous umbilical cord blood sampling may also be called cordocentesis.
• This diagnostic test involves taking a small amount of blood from the umbilical cord (fetal blood sample) and examining it for chromosome abnormalities and blood disorders in the unborn baby (fetus).
• The procedure is usually done after the 18th week of pregnancy.

Percutaneous Umbilical Cord Blood Sampling, Care After

This sheet gives you information about how to care for yourself after your procedure. Your health care provider may also give you more specific instructions. If you have problems or questions, contact your health care provider.

What can I expect after the procedure?

After the procedure, it is common to have minor cramping and discomfort.

Follow these instructions at home:

Activity

• When you get home from the procedure, rest for the remainder of the day.
• Do not lift anything that is heavier than 10 lb (4.5 kg), or the limit that you are told, until your health care provider says that it is safe.
• Return to your normal activities as told by your health care provider. Ask your health care provider what activities are safe for you.
• Ask your health care provider when it is safe for you to return to work.
• Do not have sex, douche, or put anything in your vagina until your health care provider says that it is safe.

General instructions

• Follow instructions from your health care provider about how to take care of the area where the needle was inserted to take a blood sample (insertion site). Make sure you:
  • Wash your hands with soap and water before you change your bandage (dressing), if present. If soap and water are not available, use hand sanitizer.
  • Change your dressing as told by your health care provider.
• Check your insertion site every day for signs of infection, such as redness, swelling, pain, fluid, blood, warmth to the touch, pus, or a bad smell.
• Take over-the-counter and prescription medicines only as told by your health care provider.
• Drink enough fluid to keep your urine pale yellow.
• Keep all follow-up visits as told by your health care provider. This is important.

Contact a health care provider if:

• You have pain in your abdomen.
• You have any of these problems at the insertion site:
  • Redness, swelling, or pain.
  • Fluid or blood.
  • Warmth.
  • Pus or a bad smell.

Get help right away if:

• You are bleeding from your vagina or abdomen.
• You have clear fluid (amniotic fluid) coming from your vagina.
• You have very bad cramps.
• You do not feel the baby moving as much as normal.
• You have severe pain in your abdomen.
• You have a fever.

Summary

• After the procedure, it is normal to have some discomfort and minor cramping.
• Ask your health care provider what activities are safe for you, and ask when it is safe for you to return to work or resume sexual activity.
• Contact your health care provider right away if you have bleeding from your vagina or abdomen, clear fluid coming from your vagina, very bad cramps, severe pain in your abdomen, a fever, or less movement from your baby.