Received July 20, 2022
Accepted December 02, 2022

Objective:The idea of freezing oocytes and consequently avoiding all ethical, religious, and administrative problems that frozen embryos might generate, brings another concern:Could freezing oocytes and consequently inseminating less fresh oocytes decrease the chance of pregnancy to the couples using ART?Our clinic has been freezing oocytes since 2000;therefore these data were evaluated to answer this question.This study was an observational retrospective cohort,with the objective to compare results from patients that decided to freeze oocytes versus those patients that have decided to inseminate all oocytes for the last 11years. Methods:Our data, from 2000 to 2010, includes frozen oocytes from slow freezing and vitrification techniques.All patients with more than 10 oocytes were offered the possibility to cryopreserve their oocytes.A total of 2106cycles were compared, from those, in 372cycles, the patients decided to cryopreserve oocytes.When the patients decided to freeze oocytes,the number of oocytes inseminated from 5-8) depended on the women’s age,while the extra oocytes were frozen.All patients followed clinical protocol for insemination, culturing and transferring embryos.On the day of follicular aspiration,the patients started using 90mg progesterone vaginal gel daily.Progesterone was maintained until the hCG blood test, and for those patients with results above 25UI/mL, progesterone was kept until 12weeks of pregnancy.The embryo transfers were performed with a catheter, under ultrasound control. Results:Statistical difference was observed in the number of oocytes inseminated, rate of fertilization and average of embryo transfer(p<0.05), but not in implantation and clinical pregnancy rates(p>0.05). Conclusions:Therefore these results have shown that inseminating 6 oocytes did not decrease any chance of pregnancy to the couples.