A comparative study on perinatal outcomes of red blood cell-alloimmunized pregnancies with anti-RhD in combination and anti-RhD alone in China.

Background And Objectives: The advent of intrauterine transfusion (IUT) has improved the survival of severe foetal anaemia. The aim of this study was to compare the perinatal outcomes of red blood cell (RBC)-alloimmunized pregnancies with anti-RhD in combination and anti-RhD alone in China.

Materials And Methods: A retrospective study was conducted involving RBC-alloimmunized pregnancies with anti-RhD in combination and anti-RhD alone admitted to The First Affiliated Hospital, Sun Yat-sen University, between January 2007 and December 2019. Obstetric data and neonatal outcomes were compared.

Results: A total of 165 alloimmunized pregnancies were identified, with 32 pregnancies in the anti-RhD-in-combination group (25 pregnancies with anti-RhD + anti-RhC and 7 pregnancies with anti-RhD + anti-RhE) and 133 pregnancies in the anti-RhD-alone group. The anti-RhD-in-combination group had significantly higher frequency of IUTs than the anti-RhD-alone group (59.4% [19/32] vs. 30.1% [40/133]; p < 0.01). The postnatal frequency of top-up transfusions was significantly higher in the anti-RhD in combination group than the anti-RhD-alone group (90.6% [29/32] vs. 70.7% [94/133]; p = 0.02). There was no significant difference in the frequency of exchange transfusions (ETs) between the two groups (15.6% [5/32] vs. 17.3% [23/133]; p = 0.82).

Conclusions: Compared to alloimmunized pregnancies with anti-RhD alone, pregnancies with anti-RhD in combination with anti-RhC or anti-RhE have an increased requirement for antenatal IUTs and postnatal top-up transfusions but do not have an increased need for ETs.