Tests done routinely as part of perinatal testing programs vary from country to country and within countries.
Below is one example of serologic tests typically done when pregnant females lack clinically significant antibodies. Other test protocols exist.
- ABO, Rh, and antibody screen at first prenatal visit;
- Optional (not mandated by blood safety standards): Test for weak D, if initial Rh typing appears to be D-negative;
- D-negative females: Tested again (ABO, Rh, and antibody screen) at ~ 28 weeks gestation prior to administration of RhIG (depending on the country) and again at delivery.
Note: When available, the mother can be typed for D using molecular methods, but this is usually not done unless she is weak D. The purpose is to determine, using molecular methods, which D variant the mother has, weak D or partial D, since the latter can produce anti-D.