I have an example of an anti-M that is being monitored in a maternal patient for antibody titration. Since there is a collective wealth of knowledge here I figured there would be somebody with an answer. The father is an M-positive individual and the patient has had three titers performed now, the first in October was anti-M reactive at AHG - titer of 1:8, the second titer was 1:1 - AHG, the titer performed this month was again 1:8 at AHG but had an IgM component reactive at room temperature at a 1:2 titer. My question pertains to the significance of the titer results, is the mother considered a high risk pregnancy now that both antibody types are present in her sample? Also, what woud be considered a significant rise in titer in this patient, In my limited knowledge I have the understanding that the titer should have doubled to be considered significant, is this correct in relation to anti-M? Many thanks