O-138: Preimplantation genetic diagnosis (PGD) is indicated for recurrent miscarriage even in cycles producing five or fewer embryos

Abstract

PGD is indicated for patients suffering from infertility or recurrent miscarriage when sufficient numbers of embryos are available. We have studied PGD in groups of patients with low egg yields and varying etiologies. Here we focus on patients with recurrent miscarriages. Previous studies have shown that couples with a history of idiopathic recurrent pregnancy loss (RPL) have a high incidence of chromosomally abnormal embryos. PGD for this indication has proven to significantly reduce the risk of miscarriage while producing high pregnancy rates. However, PGD is a selection tool, and when an IVF cycle produces as many or fewer embryos as the number expected to be replaced, the selection power of PGD is diminished; the same number of normal embryos may be replaced with or without PGD. The objective of this study was to determine whether PGD is indicated in patients producing 5 or fewer embryos. This study is a retrospective analysis of PGD patients with recurrent pregnancy loss in an IVF program. Patients with two or more consecutive miscarriages scheduled for PGD were included in the study. Patients with 5 or fewer embryos that were suitable for biopsy on Day 3 were asked whether or not they wished to continue with PGD analysis. Embryos were determined to be suitable for biopsy if there were at least 4 cells, with fewer than 30% fragmentation. Those who cancelled PGD were considered the “control” group, and those who decided to proceed were the ”test“ group. For the test group, single-cell biopsy was performed on Day 3, followed by fixation and PGD using FISH with probes for 9 chromosomes. Embryo replacement occurred on Day 4 for the test group. Replacement was performed on Day 3 for patients in the control group. Implantation and pregnancy rates were determined by fetal cardiac activity/number of embryos transferred or the number of retrievals. A total of 70 RPL couples produced 5 or fewer embryos that were suitable for biopsy. Of those, 47 decided to continue with the PGD procedure. The implantation and delivery rates were significantly higher in the group that received PGD (p<0.05; see Table 1). Although the spontaneous abortion rate was lower in the PGD group (4/22, 18.1% vs. 3/6, 50%), this difference was not statistically significant.Tabled 1 Even when 5 or fewer embryos were produced, the utilization of PGD was effective in increasing the delivery rate. PGD is therefore indicated for patients with idiopathic RPL irrespective of the number of embryos produced in the cycle. This finding may not be applicable to other poor responder patient groups; the effect of embryo number on other types of poor responders is under active investigation.