The development of anti-D antibodies generally results from feto-maternal haemorrhage (FMH) occurring in rhesus D (RhD)-negative women who carry an RhD-positive fetus. In later pregnancies, anti-D antibodies can cross the placenta, causing worsening rhesus haemolytic disease with each successive rhesus-positive pregnancy.
This is a companion discussion topic for the original article at https://patient.info/doctor/drug-therapy/anti-d-rho-immunoglobulin