Preimplantation genetic testing for monogenic diseases: a Brazilian IVF centre experience.

OBJECTIVE: To describe the cases of preimplantation genetic testing for monogenic diseases (PGT-M) in fertile couples who had undergone intracytoplasmic sperm injection (ICSI) cycles in a Brazilian in vitro fertilisation (IVF) centre and determine whether these cases were different from those reported from the European Society of Human Reproduction and Embryology (ESHRE). METHODS: This retrospective collection included data obtained from ICSI-PGT-M cycles between 2011 and 2016. The disease indication, number of biopsied embryos, biopsy stage, diagnosed and affected embryos, and cycles with embryo to transfer as well as implantation, pregnancy and miscarriage rates were analysed and compared to cycles without genetic diagnosis (PGT) and with ESHRE PGD Consortium collection XIV-XV. RESULTS: From 5,070 cycles performed, 72 had indications for PGT-M. The most common time for biopsy was cleavage-stage; 93% of the embryos had a diagnostic result, 59.4% of which were genetically transferable, resulting in 68% of the cycles with transferred embryos, a 22.1% implantation rate, and a 28.6% pregnancy rate. No differences in clinical outcomes of cycles with PGT-M or without PGT were observed. The day of biopsy and diagnostic success as well as implantation, pregnancy and miscarriage rates were similar to ESHRE collection. CONCLUSIONS: Although the proportion of cases with PGT-M was low, its efficacy was similar to what was reported in the European collection and represents a viable alternative for families at risk of transmitting a genetic disorder to their offspring. The main difference between our and ESHRE collection were the disease indications, which reflected the admixed, multi-ethnic Brazilian population.

Oocytes with smooth endoplasmic reticulum clusters originate blastocysts with impaired implantation potential.

OBJECTIVE: To study whether embryos derived from oocytes presenting a smooth endoplasmic reticulum cluster (SERC) are less likely to develop into blastocysts and implant. DESIGN: Transversal study. SETTING: Private university-affiliated in vitro fertilization (IVF) center. PATIENT(S): Total of 7,609 oocytes obtained from 743 intracytoplasmic sperm injection (ICSI) cycles. INTERVENTION(S): Oocytes split between the SERC-positive cycles (with at least one SERC-positive oocyte) and the SERC-negative cycles (only oocytes free of SERC). MAIN OUTCOME MEASURE(S): Embryo implantation. RESULT(S): A statistically significantly higher mean number of follicles (24.0 ± 10.5 vs. 19.6 ± 10.5), retrieved oocytes (17.8 ± 8.3 vs. 14.3 ± 8.0), and mature oocytes (13.5 ± 6.2 vs. 10.6 ± 5.9) were observed in the SERC-positive cycles as compared with SERC-negative cycles. The implantation rate was statistically significantly lower in SERC-positive cycles as compared with SERC-negative cycles (14.8% vs. 25.6%; odds ratio 0.61; 95% confidence interval, 0.44-0.86). When only cycles with in which none (0) or all the blastocysts transferred had implanted (100%) were analyzed, the mean implantation rate per transferred blastocyst in the SERC-negative group was 20.5%; no blastocysts derived from SERC-positive oocytes implanted. CONCLUSION(S): The occurrence of SERC impairs embryo implantation. Careful oocyte observation that takes into account the presence of SERC should be part of embryo selection strategy before transfer.

Freeze-all, oocyte vitrification, or fresh embryo transfer? Lessons from an egg-sharing donation program.

OBJECTIVE: To compare the outcomes of ETs using cryopreserved embryos, cryopreserved oocytes, or fresh embryos. DESIGN: Observational, cohort study. SETTING: Private university-affiliated fertility center. PATIENT(S): This study included 8,210 mature oocytes obtained from 425 oocyte donors. Of those, 5,440 were used for the donors' own cycles (Fresh Oocyte Cycles Group), and 2,770 were cryobanked for 425 recipients (Banked Donor Egg Group). All of the oocytes were sperm injected, resulting in 4,585 embryos from the donors' own cycles and 2,128 embryos from the recipients' cycles. For the donor cycles, embryos were either cryopreserved and transferred during a subsequent cycle (Thaw Cycles Group, 3,209 embryos), or they were transferred during a fresh cycle (Fresh Cycles Group, 1,307 embryos). For the recipient cycles, embryos derived from vitrified oocytes were transferred (Vitrified Oocytes Group, n = 425 cycles, 2,128 embryos). INTERVENTION(S): Oocyte/embryo vitrification and intracytoplasmic sperm injection. MAIN OUTCOME MEASURE(S): Embryo quality, pregnancy, and implantation rates. RESULT(S): Decreased embryo quality and lower rates of blastocyst formation were observed among embryos derived from vitrified oocytes. The highest pregnancy and implantation rates were noted for the Thaw Cycles Group, followed by the Banked Donor Egg Group; the Fresh Cycles Group had the lowest rates. CONCLUSION(S): Oocyte vitrification followed by intracytoplasmic sperm injection leads to lower embryo developmental competence compared with when fresh insemination methods are used. However, pregnancy and implantation rates are higher when embryos are transferred into a "more receptive" endometrium, free of the adverse effects of gonadotropin. Moreover, the freeze-all method leads to exceptional clinical outcomes.