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.