Zaporožskij Medicinskij Žurnal (Apr 2018)
Efficiency of assisted hatching of the cryopreserved–melted embryos
Abstract
Purpose. To measure outcomes of clinical research of efficiency of assisted hatching of cryopreserved embryos. Materials and methods. Patients who had un successful cycles IVF/ICSI with transfer of fresh embryos have been selected for participation in the research between 2014 and 2016 years. Patients were distributed in a random way for participation in the experiment and control groups. Results of embryos transfer of one or two cryopreserved and melted embryos were considered only. Embryos were cryopreserved at a stage of blastocyst, 5 days after extraction of oocytes by method of vitrification. Melting procedure was conducted in the morning of a day of embryos transfer following the instructions of the vitrification medium producer Cryotech (Japan). Assisted hatching was conducted with use of micropipettes of Holding Pipette Cook Medical (Australia) and Assisted Hatching/Zona Drilling Pipette Cook Medical (Australia). The treated embryos were cultivated up to a repeated estimation of morphology of embryos before transfer. Transfer of embryos has been conducted by a standard method with the use of catheter for non-invasive transfer of embryo Sydney IVF Cook Medical (Australia). The quantity of the transferred embryos varied from one to two. Results. 100 cryopreserved embryos were transferred which have been distributed in a random way either to the group with the assisted hatching or to the control group (without assisted hatching). A number of parameters of patients from both groups was analyzed, i.e. age of the patient at the time of melting of embryos, duration of infertility, causes of infertility, quantity of previous unsuccessful cycles IVF/ICSI. Any essential differences between patients within two groups based on the aforementioned parameters were not revealed. Also, there were no essential differences in number of the melted embryos, survival rate of embryos, quantity of the embryos transferred to patients. However, at the same time, parameters of positive results of tests on HCG (human chorionic gonadotropin) (42 % against 27 %) and quantity of clinical pregnancy (35 % against 24 %) were statistically higher in the group with assisted hatching comparatively to the control group (P < 0.004; P < 0.001 accordingly). Conclusions. Implantation of the transfered embryos and number of clinical pregnancies were statistically improved due to selection of the optimum freezing conditions and subsequent cultivation and conducting of procedure of mechanical incision of ZP.
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