This quick test — also called cordocentesis, fetal blood sampling, or umbilical vein sampling — examines fetal blood directly from the umbilical cord. It's used to detect disorders in the fetus.
PUBS isn't done as commonly as other diagnostic tests (such as amniocentesis and chorionic villus sampling), but may be used if results from those tests are not conclusive.
Percutaneous umbilical blood sampling usually is done in addition to an ultrasound and amniocentesis if a health care provider:
The advantage to PUBS is its speed. If the fetus might be anemic or have a platelet disorder, this test is the only way to confirm it because it uses a blood sample rather than an amniotic fluid sample. It also allows transfusion of blood or needed fluids into the baby while the needle is in place.
Your health care provider may recommend this test if:
Risks are associated with PUBS, such as miscarriage or infection. Discuss the risks and benefits with your health care provider if you choose to have this test.
This test takes a fetal blood sample by guiding a needle into the umbilical cord. A fine needle is passed through the abdomen and uterus into the umbilical cord, then the blood is withdrawn for testing.
Percutaneous umbilical blood sampling usually is done after the 18th week of pregnancy.
PUBS results usually are ready within 3 days.
Reviewed by: Armando Fuentes, MD
Date Reviewed: 02-08-2018