GVHD OR TA-GVHD

I would Like to know in transfusion aquired graft versus host disease,  Is this aquired GVHD possable in Pregnancy between mother and fetus exta- naturally? I know for a fact that MicroChimerism took place in this Pregnancy. Because my child was born with NAT. Neonatal Alloimmune Thrombocytopenia.  I have been sick with Many symptoms for almost 5 years. I have just recently come to this conclusion after much research. LThe information I have found on TA-GVHD uses the statement "Intrauterine transfusion". Which could mean between mother and fetus or it could mean between blood donation through the belly to the fetus. Which is the fact or are both?
Thank You!