The presence or absence of the Rh antigen on human red blood cells determines if a person’s blood type is “positive” or “negative.” When an Rh-negative individual, who lacks this antigen, becomes pregnant and carries an Rh-positive fetus, the mother’s immune system may recognize the fetus’s Rh antigen as foreign and mount an immune response. This phenomenon, known as Rh sensitization, can lead to complications for the fetus.

Rh immunoglobulin (RhIg), derived from human blood, is commonly administered during bleeding events in pregnancy. While its benefits in the third trimester are well-established, evidence for its use in the first trimester is lacking. Overuse in high-resource countries, especially in early pregnancy without proven benefits, increases costs and limits availability in lower-resource settings. These concerns highlight the need to revisit guidelines and address knowledge gaps.

We are speaking with Dr. Courtney Schreiber from the University of Pennsylvania about the current treatment of Rh sensitization and her recent research, which could lead to updated pregnancy care guidelines and help bridge global health equity gaps.