Umbilical cord puncture: when and why?

What is an umbilical cord puncture for?

The umbilical cord puncture (= chordocentesis or cordocentesis) serves to remove the child’s blood and tissue for diagnostic and therapeutic purposes. After a puncture in the abdominal wall of the pregnant woman, a small amount of blood is taken from a vein in the unborn child’s umbilical cord and examined. In the event of possible illnesses in the unborn child, blood or medicines are also brought into the child’s circulation via the umbilical cord. The umbilical cord puncture is monitored with ultrasound.

How does an umbilical cord puncture work?

First, the doctor uses an ultrasound examination to determine the position of the unborn child and the placenta . Then he determines a suitable place for the puncture and disinfects the abdominal wall. Local anesthesia is not usually necessary for the procedure, which only takes a few minutes. The doctor then pierces the abdominal wall under ultrasound control and pushes the thin needle to the base of the umbilical cord. He pierces the umbilical vein and takes about two milliliters of child’s blood from it. The test results are available after just one to three days.

After the umbilical cord puncture, women should lie down and rest for about 30 minutes and rest for the rest of the day. It is best to avoid heavy physical work or sporting activities the following day and take sick leave for work. The day after the puncture, a check-up appointment is scheduled. If no complications occur after the examination, sports or air travel are usually allowed again a week later.

When is an umbilical cord puncture performed?

An umbilical cord puncture can be carried out from around the 16th week of pregnancy if more precise examinations of the course of the pregnancy are desired or if the unborn child has to be treated for an existing illness.

An umbilical cord puncture is used for the following indications:

• To check after an amniotic fluid puncture (amniocentesis), where the test results are difficult to interpret.
• If there was a conspicuous result in the ultrasound examination during organ diagnostics .
• If there is a suspicion of blood group incompatibility in the unborn child.
• When chromosomal disorders are to be detected.
• If the child has an infection and pathogens or antibodies are to be detected.
• If there is a suspicion of anemia in the child.

In addition, doctors can administer medication to the unborn child via the umbilical cord, for example in the case of heart disease. Blood transfusions are also possible via the umbilical cord to treat anemia.

Complications and risks of umbilical cord puncture

The risk depends, among other things, on how experienced the doctor treating you is and what the reason for the examination is. After an umbilical cord puncture, about five to seven out of 1,000 pregnant women experience an unwanted miscarriage or premature birth due to bleeding, contractions or leakage of amniotic fluid. In very rare cases, bruising of the umbilical cord or bleeding may occur. It can also happen that the blood sample cannot be taken with the first prick. In this case, the doctor must perform a second puncture. If the child is ill and medication or blood transfusions is necessary, more than one umbilical cord puncture may be necessary.

Alternatives to umbilical cord puncture

In addition to an umbilical cord puncture, there are also alternative methods for detecting chromosomal abnormalities in the unborn child, such as amniotic fluid testing (amniocentesis) or chorionic villus sampling . If the unborn child has to be supplied with medication because of an illness, it may also be possible for the mother to administer medication.

You can read more about prenatal care and other prenatal diagnostic procedures in our “ Prenatal Diagnostics ” section.