Blood Group: Rh
Causes HDN: Yes
Critical Titer: 1:16
Anti-G can cause HDN and severe anemia (hemoglobin of 3) . IUTs and plasmapheresis can be used during pregnancy . Sometimes an antibody screen can show anti-D and anti-C when it is actually anti-G and vice versa. This is important because if it is actually anti-G, then the RhD negative woman can and should get rhogam to prevent development of the real anti-D.
1 - https://www.ncbi.nlm.nih.gov/books/NBK2269/