P-932: Embryo vitrification after biopsy (EBx) for preimplantation genetic diagnosis (PGD) to accommodate for overseas testing: Ongoing Huntington’s disease (HD)-free pregnancy following frozen-thawed transfer (FET)

Abstract

PGD for the investigation of monogenetic disorders is currently offered to couples at risk in developed countries. High costs with the setting and running of a center of excellence, hiring of professional experts make these services very difficult to afford in developing countries. Couple’s time out of work, to traveling and accommodation costs make IVF-ICSI-PGD unaffordable to a large needy population worldwide. Although there are few publications on FET followed by EBx for PGD; there were no cases described for embryo freezing after biopsy to accommodate for a safe embryo transfer (ET). World zones time differences, international courier timetables, customs requirements among other issues may prevent a time reporting of a PGD to allow for proper “uterine-embryonic implantation window”. Advances in vitrification have permitted an increasing establishment of pregnancies after frozen-thaw processes. This reports a successful singleton pregnancy after embryo biopsy - vitrification - FET in a subsequent cycle following HD-free ET in view that international blastomere transport was delayed at the origin customs. Case report. A 33 yo WMF, G0, daughter of an affected mother sought IVF-PGD alternative. After several consultations and a failed IVF-PGD abroad, the couple consented for the procedure with the understanding of possible unforeseen “roadblocks”. Pre-treatment testing checking all situations was concluded without problems. Ovarian stimulation was accomplished with a standard long protocol employing daily 225 IU of r-FSH. Twelve mature oocytes obtained were inseminated by ICSI; 10 zygotes were cultured in sequential medium. Seven morphologically superior embryos containing at least six-cells were biopsied, 1 or 2 blastomeres were removed, fixed and sent to Genesis Genetics Institute, MI, USA for analysis. Shipment was hold at Brazilian customs for an additional day; therefore we decided to vitrified the embryos by the Vitri-Safe Tip method. Briefly, the biopsied embryos were placed in an equilibrated solution (ES; 7.5% ethylene glycol, 7.5% DMSO and 20% SSS) for 5-10 min followed by introducing in vitrification solution (VS; 15% ethylene glycol, 15% DMSO, 0.5M sucrose and 20% SSS) for 30 sec. At room temperature embryos were loaded into Vitri-Safe tips, the both ends were sealed and immediately submerged in liquid nitrogen. Following the menstrual cycle, uterus priming was carried out with estradiol valerate and micronized progesterone. Three HD-free embryos were thawed in a two-steps method through dilutions of sucrose. After washing the embryos were cultured for 3 hrs and transferred via Sidney catheter. Patient established a viable singleton pregnancy currently at 12 weeks. Ultrasound exam revealed a normal nuchal translucency (1.1 cm) and without the presence of major abnormalities. To our knowledge, this is the first reported ongoing pregnancy from EBx-IVF-ICSI-PGD-HD, vitrified embryos with the Vitri-Safe Tip technique. This case illustrates that meticulous preparedness should be taken before engagement of IVF clinics from under-or-developing countries seek to help their patients. Alternative use of cryopreservation with vitrification of biopsied embryos could lead to a favorable outcome. This adds to the armamentarium of vitrifying all embryos before to international transportation of blastomeres.