PGT and deferred embryo transfer: Is blastocyst biopsy more effective than cleaved embryo biopsy?

OBJECTIVE: Blastocyst biopsy has recently been implemented in our laboratory for PGT with a "freeze all" indication. The aim of this study is to compare PGT results between embryos biopsied at the cleaved and embryos biopsied at the blastocyst stage. STUDY DESIGN: This is a retrospective cohort study conducted from January 2017 to December 2022 in France. All couples with a "freeze all" indication the day of hCG trigerring during the study period were included in the study. Patients were retrospectively assigned in one group of two groups based on the day of embryo biopsy: the cleavage group if a blastomere biopsy was performed on day 3/4 or the blastocyst group if a trophectoderm biopsy was performed on day 5/6. We evaluated and compared the results between the two groups for biological parameters and clinical outcomes. RESULTS: In total, 325 PGT cycles (291 patients) were included in our study. Frozen-thawed embryo transfer was performed for 285 cycles, 122 in the blastocyst group and 163 in the cleavage group. The number of biopsied embryos per cycle is significantly higher in the cleavage group with a mean of 7.2 ± 4.1 embryos biopsied per cycle vs. 2.9 ± 2.8 embryos in the blastocyst group (p < 0.001). The rate of the useful embryos was similar between the two groups with 14.6 % of frozen healthy embryos among the 1352 cleaved embryos obtained in blastocyst group, compared to 17.1 % in the cleavage group. No significant differences in clinical pregnancy rate per transfer and implantation rate were observed between the blastocyst and cleavage groups (36.4% vs. 40.4 % and 33.1% vs. 33.2 % respectively). CONCLUSIONS: For "freeze all" PGT cycles, the day of embryo biopsy (cleaved vs blastocyst biopsy) does not impact pregnancy outcomes. Knowing how to perform embryo biopsy at different stages helps to better organize daily laboratory activity and to rescue some undiagnosed embryos after day 3 biopsy.

Second biopsy for embryos with inconclusive results after preimplantation genetic testing: Impact on pregnancy outcomes.

In this study, we aimed to evaluate the pregnancy outcomes for embryos biopsied twice at cleavage and blastocyst stage for preimplantation genetic testing (PGT). This retrospective monocentric study, conducted between January 2016 and March 2021, described all PGT results on one hand and the PGT results for undiagnosed embryos submitted to a second biopsy on the other hand. Among the 5865 embryos biopsied during the study period, 510 embryos were genetic undiagnosed after the first embryo biopsy at cleavage stage (8.7%). The rate of undiagnosed embryos was significantly higher for PGT for structural rearrangement (PGT-SR) than PGT for monogenic disease (PGT-M) (10.2% vs 7.4% respectively, p < 0.001). Thirty-three embryos were compatible with a second biopsy at blastocyst stage before being directly frozen. Among them 17 were diagnosed as healthy for the researched pathology (51.5%). At the time of our study, 11 of the 17 preserved embryos were thawed and transferred. Embryo survival at thawing was 100% and 5 pregnancies were obtained (clinical pregnancy rate of 45.5% per transfer), including 3 live births. A second biopsy for inconclusive embryos after PGT does not seem to have an impact on thaw survival and implantation rate. For couple, this strategy avoids to discard transferable embryos.

First follow-up of art pregnancies in the context of the COVID-19 outbreak.

OBJECTIVE: The aims of this study were to follow up the monitoring, health and anxiety from women who became pregnant after an embryo transfer or a intrauterine insemination during the COVID-19 epidemic in France STUDY DESIGN: This is a single centre, retrospective study from December 2019 to March 2020 based on a phone call interview using a specific questionnaire sheet specially developed for this study. Questionnaires from 104 pregnant women were completed and descriptive data are then analyzed. RESULTS: Women with ongoing pregnancies (n = 88) did not change their physician visits. The COVID-19 outbreak has created no or few additional stresses for 77 % of pregnant women since the lockdown started. We report a miscarriage rate of 14.4 % (n = 15) and documented 10 patients (11.3 %) who had symptoms related to COVID-19. No severe symptoms and no hospitalization in intensive care unit were identified. CONCLUSION: The epidemic context did not disrupt the medical monitoring of pregnancies and we did not recover an increased rate of miscarriage after ART. None of the patients who had COVID-related symptoms presented with severe clinical manifestations. Surprisingly, pregnant women were psychologically able to experience the lockdown.