Uncomplicated oocyte donation pregnancies are associated with a higher incidence of human leukocyte antigen alloantibodies

Background

Fetuses in pregnancies conceived after oocyte donation (OD) have a higher degree of antigeneic dissimilarity with the mother compared to semi-allogeneic fetuses after natural conception. We questioned whether this leads to higher level of HLA antibody formation in OD pregnancies.

Method

Uncomplicated pregnancies after OD were compared with pregnancies conceived either spontaneously or by IVF. We calculated the number of HLA- and epitope mismatches. Maternal sera were screened for HLA antibodies with ELISA; child HLA specific antibody production was determined using CDC and Luminex with single antigen beads for class I and II.

Results

A significantly (p < 0.0001) higher incidence of HLA antibody production was observed in women conceiving after OD (69%) compared to non-donor pregnancies (24–25%). The antibody formation was positively correlated with the number of fetomaternal antigen (Spearman’s rho 0.95, p < 0.0001) and epitope mismatches (Spearman’s rho 0.91, p < 0.0001). The number of HLA-DR mismatches between women and child was an independent risk factor for the production of HLA class I specific alloantibodies.

Conclusion

Women conceiving after OD have a higher risk of developing child-specific HLA antibodies; the higher the number of immunogenetic differences, the higher the chance these antibodies are formed. The high incidence of antibody production also strongly depends upon the number of HLA-DR mismatches. Despite the stronger antibody response, OD was associated with uncomplicated pregnancy in cases included in this study.