Preconceptional diagnosis for Robertsonian translocation as an alternative to preimplantation genetic diagnosis in two situations: a pilot study.

INTRODUCTION: Preimplantation genetic diagnosis (PGD) is widely used for women heterozygous for a Robertsonian translocation. Preconceptional diagnosis (PCD), performed before fertilization, may be an alternative to PGD, especially in countries where PGD is restricted or prohibited, as in France. It could also give different information and clarify the influence of reproductive and obstetric history. METHODS: In our study, translocation was diagnosed before ICSI in five cases (group A), and after newborn or fetal aneuploidy or miscarriage in two cases, (group B). RESULTS: First polar body (PB1) analysis using acrocentric centromeric probes was done for 85 PB1s, and aneuploidy rate was at 42.4%. Oocyte aneuploidy rate differed (p<0.0001) between groups A and B (30% vs 84%). Despite the small group sizes, we demonstrate a correlation (p=0.0358) of aneuploidy rate in polar bodies after 2 or more attempts. Three live births were recorded, all in group A. DISCUSSION: PCD could thus be an alternative to PGD. This pilot study also provides new prognostic information taking into account the women's natural history, but further confirmation is required.