Percutaneous Umbilical Blood Sampling (PUBS) and Intrauterine transfusion (IUT)

PUBS (percutaneous umbilical blood sampling) is a procedure where a needle is inserted through the mother's abdominal wall and the uterine wall and usually blood is withdrawn from the umbilical vein where the umbilical cord inserts into the placenta. PUBS is a technique used for both prenatal diagnosis and prenatal treatment of the fetus.

There are a variety of conditions that can cause a fetus (baby inside the womb) to become anemic. Fetal anemia is a condition in which the baby has a low red blood cell count. Just as children and adults use red blood cells to carry oxygen, so does a fetus. It is difficult for a fetus to grow and develop when it has fewer red blood cells. If the anemia becomes too severe, the fetus may show signs of system failure and he/she may not be able to survive without treatment or delivery.

Fetal anemia may be caused by antibodies in a mother’s blood or through a fetal infection.

A specialized ultrasound doppler measurement can predict low red blood cell count or anemia in a fetus. Less often, amniocentesis can be used to estimate the level of fetal anemia due to mother's antibodies. If a fetus is found to be very anemic, a transfusion of red blood cells can be given through a narrow needle placed in the umbilical cord (PUBS), allowing the pregnancy to continue and avoiding prematurity. This is called intrauterine transfusion

An intrauterine fetal blood transfusion is done in the hospital and the mother may need to stay overnight after the procedure.