Intrauterine fetal blood transfusion for Rh disease

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An intrauterine transfusion provides blood to an Rh-positive fetus when fetal red blood cells are being destroyed by Rh antibodies.

A blood transfusion is given to replace fetal red blood cells that are being destroyed by the Rh-sensitized mother's immune system. This treatment is meant to keep the fetus healthy until he or she is mature enough to be delivered.

Transfusions can be given through the fetal abdomen (intraperitoneal transfusion) or, more commonly, by delivering the blood into the umbilical cord (umbilical or intravascular transfusion). Umbilical cord vessel transfusion is the preferred method because it permits better absorption of blood and has a higher survival rate than does intraperitoneal transfusion.

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

The mother is sedated, and an ultrasound image is obtained to determine the position of the fetus and placenta.

After the mother's abdomen is cleaned with an antiseptic solution, she is given a local anesthetic injection to numb the abdominal area where the transfusion needle will be inserted.

Medication may be given to the fetus to temporarily stop fetal movement.

Ultrasound is used to guide the needle through the mother's abdomen into the fetus's abdomen or an umbilical cord vein.
A compatible blood type (usually type O, Rh-negative) is delivered into the fetus's abdominal cavity or into an umbilical cord blood vessel.

The mother is usually given antibiotics to prevent infection. She may also be given tocolytic medication to prevent labor from beginning, though this is unusual.

What To Expect After Treatment

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

Why It Is Done

Intrauterine blood transfusions are done when:

The bilirubin level obtained from amniocentesis indicates that the fetus is moderately to severely affected by Rh sensitization.

Ultrasound shows evidence of fetal hydrops, such as swollen tissues and organs.

Doppler ultrasound of the middle cerebral artery shows anemia.

A sensitized mother's immune system can destroy a large proportion of fetal red blood cells, resulting in severe anemia. An intrauterine blood transfusion may be done immediately when fetal blood sampling (FBS) indicates that the fetus has severe anemia.

In a severely affected fetus, transfusions are done every 1 to 4 weeks until the fetus is mature enough to be delivered safely. Amniocentesis may be done to determine the maturity of the fetus's lungs before delivery is scheduled.

How Well It Works

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.

Studies have shown the overall risk of fetal death from intraperitoneal transfusions is about 8% in fetuses without hydrops and 25% to 56% for fetuses with hydrops. 3 The high death rate in fetuses with hydrops is due to poor absorption of the red blood cells.

Fetuses with hydrops are more successfully treated with an umbilical transfusion because the blood is delivered directly into the fetal blood system and does not need to be absorbed from the abdomen.

Intravascular transfusion reverses hydrops in 60% to 70% of cases.

Risks

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.

What To Think About

Umbilical blood transfusions can be done as early as 17 weeks into the pregnancy, although it is preferable to wait until 20 weeks.

Umbilical blood transfusions are more effective than intraperitoneal blood transfusions, especially in a severely ill fetus. Blood absorption after intraperitoneal transfusion is slower than with an umbilical transfusion, which delivers the blood directly into a fetal blood vessel.

Umbilical transfusions are more commonly used than intraperitoneal transfusions, which have a significantly higher risk of complications and fetal death.

2012-01-11