What is intrauterine fetal blood transfusion?

An intrauterine transfusion provides blood to an Rh-positive fetus when fetal red blood cells are being destroyed by the Rh-sensitized mother's immune system. This treatment is meant to keep the fetus healthy until the baby is mature enough to be delivered.

Transfusions can be given through the fetal abdomen or, more often, by delivering the blood into the umbilical vein or artery.

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

Fetal survival after transfusion depends upon the severity of the fetus's illness, the method of transfusion, and the skill of the doctor who does the procedure. Overall, after intrauterine transfusion through the umbilical cord:

• More than 90% of fetuses that do not have hydrops survive.
• About 75% of fetuses that have hydrops survive.

Intrauterine transfusions may cause:

• Uterine infection.
• Fetal infection.
• Preterm labor.
• Excessive bleeding and mixing of fetal and maternal blood.
• Amniotic fluid leakage from the uterus.
• Fetal death.

A short recovery period (approximately 1 to 3 hours) is needed to allow the mother's sedatives to wear off. If the fetus was given medicine to prevent movement, it may be several hours until the mother can feel the fetus moving again.

An intrauterine blood transfusion may be done to replace fetal red blood cells that are being destroyed by an Rh-sensitized mother's immune system (Rh disease). These transfusions are done when:

• Doppler ultrasound of the middle cerebral artery suggests anemia.
• The bilirubin result from amniocentesis testing shows that the fetus is moderately to severely affected by Rh sensitization.
• Ultrasound shows evidence of fetal hydrops, such as swollen tissues and organs.
• Fetal blood sampling (FBS) shows that the fetus has severe anemia. The transfusion may be done right away.

In a severely affected fetus, transfusions are done every 1 to 4 weeks until the fetus is mature enough to be delivered safely.

• The mother is sedated. Then an ultrasound image is taken to find out the position of the fetus and placenta.
• After the mother's belly is cleaned with an antiseptic liquid, the mother is given a shot of local anesthetic . The shot numbs the area of the belly where the transfusion needle will be put in.
• Medicine may be given to the fetus to stop the fetus from moving for a short time.
• Ultrasound is used to guide the needle through the mother's belly and into the fetus's belly or an umbilical cord vein.
• A compatible blood type (usually type O, Rh-negative) is delivered into the fetus's umbilical cord blood vessel.
• The mother is usually given antibiotics to prevent infection. The mother may also be given tocolytic medicine to prevent labor from starting, though this is unusual.