Prenatal RHD Test

Primary Uses of the RhD Test

Blood Typing - The RhD test is used alongside ABO blood typing.

• If a person has the RhD antigen, they are Rh-positive.
• If they lack the RhD antigen, they are Rh-negative.
• This is crucial for safe blood transfusions and pregnancies.

What is the RhD Test in Pregnancy?

The RhD test checks whether the mother has the RhD antigen on her red blood cells. If the mother is Rh(-) and the fetus is Rh(+), her immune system may produce antibodies against the baby's red blood cells. The risk associated with the mismatch between fetal and mother Rh factor can destroy the baby’s red blood cells, lead to anemia, jaundice, or even stillbirth.

Why Is It Important?

If an Rh(-) mother is carrying an Rh(+) fetus, her immune system may see the baby's red blood cells as foreign and produce antibodies against them causing hemolytic disease of the fetus and newborn (HDFN).

Non-Invasive Fetal RhD Testing

Forensic Genetics Laboratory uses the blood test from the mother and detects the fetus's RhD status (using fetal DNA in the mother's blood). The testing is available starting from 10 weeks of pregnancy. Non-invasive fetal RhD blood group genotyping is meant to identify Rh compatibility between a pregnant person and their fetus. It offers the potential to avoid unnecessary treatment or invasive forms of fetal Rh group identification. Please note that the test is valid for Rh(-) pregnant women only.