Fetal Blood Sampling
Fetal blood sampling is a procedure to remove a small amount of blood from the fetus during pregnancy. Fetal blood sampling is usually done by a specially trained perinatologist, a doctor who specializes in the care of the fetus in high-risk pregnancies. It is done as part of diagnosing, treating, and monitoring fetal problems at various times during pregnancy.
A fetal blood sample may be taken to:
- Diagnose genetic or chromosome abnormalities
- Check for and treat severe fetal anemia or other blood problems such as Rh disease
- Check fetal oxygen levels
- Check for fetal infection
- Give certain medications to the fetus
There are several ways blood can be obtained from the fetus. After cleansing the mother's abdomen with antiseptic, a long, thin needle is inserted into the mother's uterus guided by ultrasound. Blood may be taken from the following sources:
- Blood vessels of the umbilical cord (also called cordocentesis, or percutaneous umbilical blood sampling, or PUBS)
- A fetal blood vessel, usually in the liver or heart
Fetal blood transfusions are done using a similar technique. The fetus either receives blood or has unhealthy blood exchanged for healthy blood to treat some problems. In this case, it may be necessary to give a sedative medication to keep the baby from moving.
After a fetal blood sampling procedure, mothers will need to rest in the hospital and have the fetal heart rate monitored for a few hours.
Benefits and risks of fetal blood sampling
Fetal blood sampling is a very complex procedure that must be done by a specially trained doctor. It is used when other tests or procedures are not possible or not effective. It can be done for pregnancies that are 18 weeks or later.
Benefits of fetal blood sampling is that it provides specialized information about the health of the fetus and fetuses with severe blood damaging diseases can be treated before birth.
The following are risks associated with fetal blood sampling:
- Bleeding from the fetal blood sampling site
- Changes in the fetal heart rate
- Leaking of amniotic fluid
If you have questions regarding fetal blood sampling during pregnancy, call (314) 996-5433 or email us to speak with a doctor.