Human Uterine Lavage: First Live Births from In Vivo Conceived Genetically Screened Blastocysts.

INTRODUCTION: We wish to report the first live births from genetically screened human euploid blastocysts obtained by uterine lavage. The embryos transferred to infertile women were previously obtained using a novel fully automated uterine lavage catheter and fluid recovery device developed for this indication. The objective of this portion of the research was to confirm embryo implantation and live births with these unique in vivo conceived blastocysts obtained by uterine lavage. METHODS: In vivo conceived embryos recovered by uterine lavage 5 days after intrauterine insemination were available for embryo donation. In vivo embryos were the result of prior controlled ovarian stimulation cycles in oocyte donors and intrauterine insemination with donor sperm. An observational case series of nine embryo transfer procedures was performed at an outpatient fertility center. One to two embryos were transferred to eight infertile women since one woman had two separate embryo transfer procedures. RESULTS: Nine embryo transfer procedures were performed with 14 blastocysts in eight women resulting in a blastocyst implantation rate of 36% (5/14) and live birth rate of 44% (4/9). Five infants have been born from the four delivered pregnancies with one set of twins. CONCLUSIONS: This is the first report of live births from genetically screened human euploid blastocysts obtained by uterine lavage. The nonsurgical uterine lavage office procedure represents the only current approach to obtain in vivo conceived embryos and can provide a benchmark for comparison to standard in vitro cultured blastocysts. Live births of in vivo conceived blastocysts represent the validation that the nonsurgical uterine lavage procedure allows simplified access to naturally conceived embryos without performing the surgical procedure of an oocyte aspiration. Owing to its simplicity, uterine lavage may be useful in screening embryos for preimplantation genetic testing for aneuploidy in fertile and infertile couples. TRIAL REGISTRATION NUMBER: ClinicalTrials.gov (Identifier NCT03426007).

The overall goal of this research was to develop a procedure that would allow collection of naturally conceived human embryos and compare them to embryos that result from the standard process of in vitro fertilization (IVF). IVF is a procedure where eggs are surgically removed from the ovaries and fertilized with sperm in a laboratory. Embryos from IVF are cultured for 3­7 days before they are placed back into a woman's uterus to establish a pregnancy. Uterine lavage is a different procedure where the sperm fertilizes an egg in the normal process of conception and the uterus is rinsed with fluid to recover the embryo before implantation. The embryos reported in this study were the first to be obtained in over 30 years owing to many improvements in the overall uterine lavage procedure. Until our initial study findings reported in 2020, the vast majority of information on embryo development was based on embryos fertilized and cultured in a laboratory. Our prior report of embryos obtained by uterine lavage compared with IVF embryos from the same women demonstrated a significantly better appearance of the embryos recovered by lavage. This current report documents the first live births from these genetically screened naturally conceived human embryos. The live births provide evidence that uterine lavage allows ready access to normal embryos without performing the surgical procedure IVF. Owing to the simplicity of uterine lavage, the procedure may improve access to genetic testing of embryos before pregnancy.

First PGT-A using human in vivo blastocysts recovered by uterine lavage: comparison with matched IVF embryo controls†.

STUDY QUESTION: After controlled ovarian stimulation (COS) and IUI, is it clinically feasible to recover in vivo conceived and matured human blastocysts by uterine lavage from fertile women for preimplantation genetic testing for aneuploidy (PGT-A) and compare their PGT-A and Gardner scale morphology scores with paired blastocysts from IVF control cycles? SUMMARY ANSWER: In a consecutive series of 134 COS cycles using gonadotrophin stimulation followed by IUI, uterine lavage recovered 136 embryos in 42% (56/134) of study cycles, with comparable in vivo and in vitro euploidy rates but better morphology in in vivo embryos. WHAT IS KNOWN ALREADY: In vivo developed embryos studied in animal models possess different characteristics compared to in vitro developed embryos of similar species. Such comparative studies between in vivo and in vitro human embryos have not been reported owing to lack of a reliable method to recover human embryos. STUDY DESIGN, SIZE, DURATION: We performed a single-site, prospective controlled trial in women (n = 81) to evaluate the safety, efficacy and feasibility of a novel uterine lavage catheter and fluid recovery device. All lavages were performed in a private facility with a specialized fertility unit, from August 2017 to June 2018. Subjects were followed for 30 days post-lavage to monitor for clinical outcomes and delayed complications. In 20 lavage subjects, a single IVF cycle (control group) with the same ovarian stimulation protocol was performed for a comparison of in vivo to in vitro blastocysts. PARTICIPANTS/MATERIALS, SETTINGS, METHODS: Women were stimulated with gonadotrophins for COS. The ovulation trigger was given when there were at least two dominant follicles ≥18 mm, followed by IUI of sperm. Uterine lavage occurred 4-6 days after the IUI. A subset of 20 women had a lavage cycle procedure followed by an IVF cycle (control IVF group). Recovered embryos were characterized morphologically, underwent trophectoderm (TE) biopsy, vitrified and stored in liquid nitrogen. Biopsies were analyzed using the next-generation sequencing technique. After lavage, GnRH antagonist injections were administered to induce menstruation. MAIN RESULTS AND THE ROLE OF CHANCE: A total of 134 lavage cycles were performed in 81 women. Uterine lavage recovered 136 embryos in 56 (42%) cycles. At the time of cryopreservation, there were 40 (30%) multi-cell embryos and 96 (70%) blastocysts. Blastocysts were of good quality, with 74% (70/95) being Gardener grade 3BB or higher grade. Lavage blastocysts had significantly higher morphology scores than the control IVF embryos as determined by chi-square analysis (P < 0.05). This is the first study to recover in vivo derived human blastocysts following ovarian stimulation for embryo genetic characterization. Recovered blastocysts showed rates of chromosome euploidy similar to the rates found in the control IVF embryos. In 11 cycles (8.2%), detectable levels of hCG were present 13 days after IUI, which regressed spontaneously in two cases and declined after an endometrial curettage in two cases. Persistent hCG levels were resolved after methotrexate in three cases and four cases received both curettage and methotrexate. LIMITATIONS, REASON FOR CAUTION: The first objective was to evaluate the feasibility of uterine lavage following ovarian stimulation to recover blastocysts for analysis, and that goal was achieved. However, the uterine lavage system was not completely optimized in our earlier experience to levels that were achieved late in the clinical study and will be expected in clinical service. The frequency of chromosome abnormalities of in vivo and IVF control embryos was similar, but this was a small-size study. However, compared to larger historical datasets of in vitro embryos, the in vivo genetic results are within the range of high-quality in vitro embryos. WIDER IMPLICATIONS OF THE FINDINGS: Uterine lavage offers a nonsurgical, minimally invasive strategy for recovery of embryos from fertile women who do not want or need IVF and who desire PGT, fertility preservation of embryos or reciprocal IVF for lesbian couples. From a research and potential clinical perspective, this technique provides a novel platform for the use of in vivo conceived human embryos as the ultimate benchmark standard for future and current ART methods. STUDY FUNDING/COMPETING INTEREST(S): Previvo Genetics, Inc., is the sole sponsor for the Punta Mita, Mexico, clinical study. S.M. performs consulting for CooperGenomics. J.E.B. and S.A.C. are co-inventors on issued patents and patents owned by Previvo and ownshares of Previvo. S.N. is a co-author on a non-provisional patent application owned by Previvo and holds stock options in Previvo. S.T.N. and M.J.A. report consulting fees from Previvo. S.T.N., S.M., M.V.S., M.J.A., C.N. and J.E.B. are members of the Previvo Scientific Advisory Board (SAB) and hold stock options in Previvo. J.E.B and S. M are members of the Previvo Board of Directors. A.N. and K.C. are employees of Previvo Genetics. L.V.M, T.M.M, J.L.R and S. S have no conflicts to disclose. TRIAL REGISTRATION NUMBER: Protocol Registration and Results System (PRS) Trial Registration Number and Name: Punta Mita Study TD-2104: Clinical Trials NCT03426007.

Novel uterine lavage system for recovery of human embryos fertilized and matured in vivo.

Purpose: In this paper we describe a novel uterine lavage system for the recovery of in vivo preimplantation embryos. Currently, no other method exists to retrieve preimplantation embryos except for in vitro fertilization (IVF). Methods: A single center, prospective feasibility study was conducted to test a novel uterine lavage system for the recovery of in vivo preimplantation embryos in egg donors and patients seeking pregnancy. Subjects were placed on controlled ovarian hyperstimulation followed by intrauterine insemination (IUI) and uterine lavage performed approximately 4-6 days after IUI. Subjects were followed up for 30 days after the procedure to monitor for safety events. Results: A total of 134 uterine lavage cycles were performed on 81 subjects (average: 1.7 cycles/subject). Ova (oocytes or embryos) were collected in 53% (71/134) of the cycles with steady improvement of recovery efficiency over the course of the study, and embryos collected in 42% (56/134) of cycles. Embryos of many stages were collected, but 71% (96/136) of embryos collected were blastocyst stage embryos which are at the most advanced stage of embryogenesis. Embryos recovered were of good quality based on blastocyst gradings in which 74% (70/95, 1 blastocyst not graded) of the blastocysts were good quality as determined by the Gardner Scale of Morphology. The procedure was well tolerated with minor side effects. In 8% of cycles a positive hCG was observed after the lavage indicating some embryos were not recovered by the lavage system. Conclusion: Through this work the system has been shown to recover embryos from the uterus in a safe and effective manner, thus opening the possibility that uterine lavage may serve as an alternative to IVF where patient indications allow.