Percutaneous umbilical cord blood sampling (
PUBS), also called
cordocentesis,
fetal blood sampling, or
umbilical vein sampling is a diagnostic
genetic test that examines blood from the
fetal umbilical cord to detect fetal abnormalities. Fetal and maternal blood supply are typically connected
in utero with one vein and two arteries to the fetus. The
umbilical vein is responsible for delivering oxygen rich blood to the fetus from the mother; the
umbilical arteries are responsible for removing oxygen poor blood from the fetus. This allows for the fetus’ tissues to properly
perfuse. PUBS provides a means of rapid
chromosome analysis and is useful when information cannot be obtained through
amniocentesis,
chorionic villus sampling, or
ultrasound (or if the results of these tests were inconclusive); this test carries a significant risk of complication and is typically reserved for
pregnancies determined to be at high risk for
genetic defect. It has been used with mothers with
immune thrombocytopenic purpura.