Today, preimplantation genetic screening (PGS) is performed at the blastocyst stage by removing trophectoderm cells. The biopsy can be done at the blastocyst stage on day 5 or day 6. Elective single embryo transfer (eSET) is key to healthy singleton pregnancies. This outcome can be further improved by transferring a single euploid embryo. One would expect that a euploid embryo regardless of the day of biopsy should have an equal potential to implant. Therefore, we were looking into single euploid transfers using day 5 blastocysts and compare it to single euploid day 6 blastocysts.

OBJECTIVE: To determine the clinical benefits of PGD using array comparative genome hybridization (aCGH) and day 3 biopsy. DESIGN: Comparative study. MATERIALS AND METHODS: Patients included had advanced maternal age (AMA) or recurrent pregnancy loss (RPL). PGD was performed using single-cell day-3 biopsy, aCGH, and day-5 transfer. 151 cycles of PGD were performed on women of average age 37.2 in 18 infertility centers. Each PGD patient was matched with the average pregnancy outcome of its fertility center for non-PGD patients of the same age of the PGD patient. Ongoing pregnancy was considered one that past second trimester. Non replaced embryos were reanalyzed by FISH with 19 probes to determine the error rate. RESULTS: Only 118/151 (78.1%) PGD cycles had normal embryos for transfer. Reanalysis of all cells of non-replaced embryos showed that 98% of them were correctly diagnosed. Only 1.3 embryos on average were replaced in the PGD group. The pregnancy rate for the PGD group was 46% per cycle and 59% per transfer compared with 37.6% per cycle (N.S.) and 38% per transfer (p<0.001). The ongoing pregnancy rate for the PGD group was 42% per cycle and 54% per transfer, compared with 31% (N.S.) and 31% (p<0.001), respectively for the control group. For RPL cycles (n-35) the ongoing pregnancy rate was 63% per cycle and 57% per transfer.Tabled 1pregnancy rate / cyclepregnancy rate / transferongoing pregnancy rate / cycleongoing pregnancy rate / transfercontrol38%38%31%31%PGD46%59%42%54%p valueNS<0.001NS<0.001 Open table in a new tab CONCLUSION: Many AMA patients undergo PGD as a mean to determine if they produce any normal embryos and if not to progress to egg donation. In this data set, 22% of AMA patients had no normal embryos. For patients with at least one normal embryo, the ongoing pregnancy rate was significantly improved after PGD with aCGH. IVF/PGD with aCGH may help women with no normal embryos to progress to egg donation and patients with normal embryos conceive with their own eggs.

OBJECTIVE: Preimplantation Genetic Diagnosis and Screening are used in an effort to decrease trisomic conceptions, decrease spontaneous miscarriage and to detect genetic disease. The impact of embryo biopsy on the ability to cryopreserve surplus embryos in PGS cycles needs to be considered, particularly since early reports described reduced viability. The purpose of this study is to demonstrate the effectiveness of the new S3-vitrification method on blastocysts derived from PGS. DESIGN: Retrospective analysis. MATERIALS AND METHODS: From January 2007 through February 2008, 28 patients had cryo-transfers of normal surplus blastocysts - that were vitrified using S3 vitrification during PGS cycles. Embryos were vitrified using several important modifications of regular vitrification. The new S3 approach uses a DMSO-free environment and standard sealable freezing straws. Pre-vitrification steps with this protocol allow for a three-fold duration of exposure time to cryoprotectants. Post-thaw survival was carefully observed. The average number of embryos transferred was 2.1 (range 1-3). RESULTS: All 28 patients had at least one embryo survive for cryotransfer. A total of 67 blastocysts were thawed and 63 of the these survived (94%). 18 of the patients had a positive pregnancy test and 16 of those had a clinical pregnancy (57%). There was one patient who had a spontaneous miscarriage (6.2%). The Implantation rate was 31.7%. We anticipate from this data that the incidence of birth will be in excess of 45%. CONCLUSIONS: This study clearly demonstrates the viability of blastocysts after biopsy on day three and PGS using S3-vitrification. The notion that such embryos do poorly after cryostorage can not be confirmed. The advantage of the new S3 approach is not only demonstrated in increased viability and pregnancy, but also in the shortened learning curve observed when embryologists unfamiliar with this technique were retrained.

OBJECTIVE: There is considerable controversy surrounding the role of PGS in ART. One of the major concerns shared by many is the possible adverse effect of blastomere biopsy on implantation potential. It can be argued that the effectiveness of PGS may be measured more accurately when it is applied in donor egg cycles. The purpose of this study was to compare the outcome of IVF in donor egg recipients with a day 5 embryo transfer without PGS and donor egg recipients who requested and had PGS. DESIGN: Retrospective cohort study. MATERIALS AND METHODS: From January 2006 through January 2008 - there were 188 non-PGS donor egg day 5 embryo transfers and 44 donor egg day 5 PGS embryo transfers. For the PGS group a single cell was removed from each embryo that had progressed to at least 4 cells on day 3, -the embryos were cultured to day 5 before transfer. Fixed blastomeres were sent to a reference lab where FISH was performed using a panel of 9 chromosomes. ICSI was used in all cycles and - all embryos were cultured in Global medium from day 1 to day 5. All blastocysts in the non-PGS group had assisted hatching prior to replacement on day 5. RESULTS: The donors' demographics, stimulation protocols and cycle parameters were similar in the two groups. Mean donor age in the non-PGS and PGS groups were 25.9 ± 3.4 years (range 21 to 36 years), and 26.1 ± 3.2 years (range 21-32 years), respectively. The maturation rate of retrieved eggs was similar in the non- PGS group (70.4%), and the PGS group (71.2%), and there was no difference in fertilization rates between the two groups (90.5% vs. 90.0%). Cycle outcomes are shown in the table below. Overall pregnancy rates, loss rates, and implantation rates were the same in the two groups. Early pregnancy loss rate was notably reduced in the PGS group, but the difference did not reach statistical significance. Moreover, there were - 14 (13.3%) cases of vanishing twins in the non-PGS group which is not reflected in the loss rates. It is noteworthy that both SAB's in the PGS group involved severe male factor.Table 1Cycle OutcomesDonor Egg Day 5 no-PGSDonor Egg Day 5 with PGSEmbryo Transfer no.18844Clinical Pregnancy Rate64.4%68.2%n.s.Loss Rate13.2%6.6%n.s.Implantation Rate45.8%48.8%n.s. Open table in a new tab CONCLUSIONS: PGS is not detrimental to pregnancy rates in donor egg recipients. PGS may reduce the rate of early pregnancy loss and may prevent trisomic conceptions in patients unwilling to contemplate invasive prenatal diagnosis.