Clinical and Experimental Obstetrics & Gynecology (CEOG) is published by IMR Press from Volume 47 Issue 1 (2020). Previous articles were published by another publisher on a subscription basis, and they are hosted by IMR Press on imrpress.com as a courtesy and upon agreement with S.O.G.
The successful use of hatched blastocysts in assisted reproductive technology
This retrospective study was undertaken to determine the value of blastocyst culture and transfer as a tool in assisted reproductive technology. Six hundred and fifty-five cycles in patients undergoing IVF treatment for infertility were involved. All patients were aged ≤40 years. Day-2 embryos were transferred to 427 (group 1) and day-6 embryos (blastocysts) were transferred to 228 patients (group 2). Pronucleate oocytes obtained from IVF were cultured in vitro for 2 or 6 days. One to five embryos were transf erred. A total of 10,146 oocytes were retrieved, 6,105 oocytes were fertilized, 2,222 embryos were transferred and 197 clinical pregnancies were achieved in all groups. Blastocystes were transferred to almost 90% of group 2 patients. The pregnancy rate per cycle and implantation rate per transferred embryo was 42.1 % and 19.4%, respectively, in the blastocyst group compared to 23.6% and 8.6%, respectively, when embryos were transferred on day 2. Even though in the blastocyst group there was an increased number of oocytes fertilized at the same time there was a significant reduction in the number of embryos being replaced (3.2 vs 3.8). This study demonstrate that transfer of blastocysts increases the success of IVF when compared with day-2 transfers and reduces the number of embryos to be transferred.