Solved problems of reproductive medicine in the Czech Republic 2020.

INTRODUCTION: During the 30th symposium of assisted reproduction held on November 11, 2020 in Brno, the solved problems in reproductive medicine in the Czech Republic in 2020 were presented. The selected topics have concerned not only current issues in the field of clinical embryology and genetics as well as gynecology, but also legislation and ethics. Discussed topics: 1. How much time does the doctor have in the CAR (centrum of assisted reproduction) outpatient clinic per patient and how does the embryologist communicate with clients? 2. Reproduction and PGT-M in oncology patients and patients at risk with hereditary oncogenic mutations. 3. Non-invasive genetic testing of embryos from culture medium. 4. Genome editing. 5. What is the need to monitor hormonal levels in stimulation protocols? 6. Monitoring and embryo selection for transfer/kryo. 7. Is it time to change the law on donor remuneration? METHODS: The topics were prepared in advance by authorized members of our company with the task of elaborating theses, which they presented in a separate conference block. The presentation and the discussion were broadcast directly from the broadcast studio at Hotel International via an online connection. After the conference, all discussion topics and comments were incorporated. CONCLUSION: The work presents the state of the solved problems of reproductive medicine in the Czech Republic.

Improved implantation rate after chemical removal of the zona pellucida.

OBJECTIVE: To evaluate the implantation rate achieved after chemical removal of the zona pellucida from day 5 human in vitro-derived embryos. DESIGN: Prospective, randomized, controlled study. SETTING: A tertiary care infertility clinic. PATIENT(S): Two hundred fifty-seven patients undergoing IVF with transfer of morulas or blastocysts on day 5 after oocyte retrieval. All patients had had at least two previous implantation failures. INTERVENTION(S): Chemical removal of zona pellucida by using acidic Tyrode's solution vs. no removal (controls). MAIN OUTCOME MEASURES: Clinical pregnancy rate and implantation rate per transfer. RESULT(S): Embryos without zona pellucida implanted at nearly twice the rate of control embryos (15.7% vs. 27.5%). The pregnancy rate was also significantly higher in the zona pellucida-free group than the control group (31.0% vs. 46.1%). Removal of zona pellucida was most effective in embryos with delayed development, which reached the morula or early cavitating stage on day 5 of in vitro culture (implantation rate, 12.1% vs. 25.7%). CONCLUSION(S): Chemical removal of zona pellucida from day 5 in vitro cultured human embryos is an effective and safe method of significantly improving the implantation rate, especially of embryos with delayed development.

Twin pregnancy after vitrification of 2-pronuclei human embryos.

OBJECTIVE: To report an ongoing twin pregnancy after transfer of embryos that were vitrified at the 2-pronuclei stage in a new vitrification solution. DESIGN: Case report. SETTING: A tertiary-care infertility clinic. PATIENT(S): A 26-year-old infertile woman in whom two previous IVF implantations failed. INTERVENTION(S): Vitrification of 2-pronuclei embryos, in vitro culture for 48 hours, and transfer into the uterus. MAIN OUTCOME MEASURE(S): Survival and cleavage after vitrification and achievement of clinical pregnancy. RESULT(S): Six zygotes were vitrified by using a three-step protocol (4% ethylene glycol for 3 minutes, 20% ethylene glycol for 1 minute, and 38% ethylene glycol and 1.2 M trehalose for 0.5 minute). After 2 months of storage in a double-straw system in liquid nitrogen, two zygotes were warmed and cryoprotectants were removed by using a four-step protocol (1 M, 0.5 M, 0.25 M, and 0.125 M of trehalose). Two embryos were transferred after 48 hours of in vitro culture, cleaving to 5 and 6 cells. The resulting twin pregnancy was confirmed by ultrasonography at the sixth week. CONCLUSION(S): Vitrification by using ethylene glycol and trehalose appears to be a safe, promising method for cryopreservation of human zygotes. Storage of vitrified zygotes in a double-straw system does not compromise their subsequent potential for survival and development.