Is there any predictive value of first polar body morphology for embryo genotype or developmental potential?

The first polar body (PB1) was previously used for genotyping oocytes in preimplantation genetic diagnosis (PGD) for Mendelian and chromosomal disorders. A possible use of PB1 morphology for predicting developmental potential was also explored in a few retrospective studies, which showed controversial results. PB1 morphology was evaluated in a prospective study of 831 oocytes, which were then followed up through preimplantation development, with analysis of fertilization rate, embryo quality, survival to blastocyst, and outcome of embryo transfer, demonstrating no correlation with PB1 morphology. There was also no evidence for a PB1 predictive value for these parameters either in good or poor responder patients. An additional 358 oocytes and embryos from patients requesting PGD were tested for aneuploidies, revealing no relationship with PB1 morphology either. This suggests that PB1 morphology may not be a reliable predictor of genotype or the developmental potential of the corresponding oocytes or embryos.