Type ab plasma contains no lectin, and the membrane component is ab.
Give birth to a child, which may be type A (ai) or type B (bi).
Because the mother is O-type and has lectins for A and B, theoretically all babies should be hemolyzed, but in fact it is not that terrible.
The antigen-antibody reaction of abo system is not very violent, and it is not as serious as Rh hemolysis, so the incidence is there, but it is not very high and the consequences are not very serious.
You can consult a gynecologist.