Overview
Why Rh Status Matters in Pregnancy
An antenatal blood group result does more than prepare a transfusion record.
An antenatal blood group result does more than prepare a transfusion record. ABO group helps match blood; RhD status determines whether fetal red cells could prime a maternal immune response. An RhD-negative pregnant patient can feel entirely well while becoming sensitized after fetomaternal haemorrhage. Once immune anti-D exists, it can cross the placenta in a D-positive pregnancy and destroy fetal red cells. The nurse's first clinical question is therefore not simply whether the patient is Rh-negative, but whether she is unsensitized, whether the fetus could be D-positive, and whether a sensitizing event has occurred.