Noninvasive management of Rh partial null (D--) to supplement traditional management of Rh isoimmunization

Rh partial null (D--) is a rare cause of Rh sensitization in an Rh-positive patient. Noninvasive management for this condition using middle cerebral artery Doppler studies was used to reduce invasive testing.

An Rh D+ woman had an antibody titer of 1:512 to Rh-17, the Rh Cc/Ee protein. Rh typing revealed absence of any antigens at the Cc/Ee locus. Her husband was Rh D--, ccee. Middle cerebral artery Doppler studies and serial amniocenteses for Delta OD(450) were performed. When testing suggested severe fetal anemia, two intrauterine transfusions were performed.

Middle cerebral artery Doppler studies can be used to predict fetal anemia before the first transfusion. However, the cutoff to predict subsequent anemia in Rh D-- after transfusion remains to be defined.