Clinical Characteristics of Jra Alloimmunization in Pregnancy: A Case Series

Only few studies have reported on Jra alloimmunization in pregnancy, and its clinical course remains unclear. We reviewed our cases to clarify the change in the peak systolic velocity of the middle cerebral artery (MCA-PSV) during pregnancy and the critical anti-Jra antibody titer to predict fetal anemia. We collected the data of pregnant women with anti-Jra antibody from two hospitals between 2010 and 2017. We extracted data on maternal information, number of intrauterine blood transfusions (IUT), trend of anti-Jra antibody titer, changes of MCA-PSV, and neonatal outcome. We had 16 cases. IUTs were performed in 6 fetuses with severe anemia between 27 and 32 weeks' gestation. The MCA-PSV did not increase more than 1.5 multiples of the median (MoM) after 32 weeks' gestation. No significant difference was found in the maximum titer between cases with IUT and those without IUT. All pregnancies but one delivered at term. No neonates developed severe anemia or jaundice. MCA-PSV did not increase higher than 1.5 MoM later during the pregnancy. A critical titer to predict fetal anemia did not exist. Spontaneous term delivery could be expected even in fetuses who underwent IUT before 32 weeks' gestation.