Non-surgical flushing of the uterus for pre-embryo recovery: possible clinical applications

Growing interest in preimplantation genetic diagnosis has indicated uterine flushing as one method for obtaining human preimplantation embryos. To date, our institution has performed non-surgical uterine flushing to donate the recovered embryos to infertile recipients. We performed 127 flushings in 127 cycles using a modified urinary bladder catheter. Using the donors' natural cycles, a single ovum was recuperated in 37 out of 88 flushings. In 17 flushings, clomiphene citrate was given to the donors and 14 ova were found in nine positive recoveries. Human menopausal gonadotrophins were administered to the donors in 22 flushings and 22 ova were located in 14 positive recoveries. In total, 22 blastocysts, 11 morulae and 13 pre-embryos at the 2- to 16-cell stages were found. When transferred, these embryos gave rise to 18 clinical pregnancies in the recipients (40.9% of the transfers; 14.1% of the flushings). In comparison with natural cycles, superovulation of donors did not significantly increase the recipients' pregnancy rate. At present, non-surgical recovery of uterine pre-embryos does not seem to carry much potential as a tool for infertility treatment, or for genetic diagnosis. This is because currently available alternative methods are more successful.