Successful pregnancy derived from slowly freezing donated human oocytes by intracytoplasmic sperm injection / 中华泌尿外科杂志

ABSTRACT

Objective To set up a novel clinical method for storage of oocytes by slowly freezing and successful pregnancy by intracytoplasmic sperm injection (ICSI). Methods The frozen oocytes (n=33) in metaphase Ⅱ (28),which were normal in morphology,were denuded of their cumulus-corona complex.The protective freezing solution contained 1,2-propanediol (1.5 mol/L) and sucrose (0.35 mol/L) and the process was slow for freezing and rapid for thawing.The recipients of these oocytes received hormone replacement therapy (HRT). Results A high survival rate of oocytes (32/33) was obtained when the sucrose concentration was 0.35 mol/L.ICSI induced a higher fertility rate (23/28),a good embryo cleavage rate (21/23) and a satisfactory embryo morphology for thawed oocytes.Embryo transfers were performed in 6 cycles/6 cases. Four cases got clinical pregnancy by demonstration of four gestation sacs on B ultrasonic examination 7 weeks after ICSI,1 fetal was first trimester spontaneous abortion,another 3 survival fetal were ongoing pregnancy and the first case gestation week is 17 weeks. Conclusions This study is the first successful application of human oocyte cryopreservation in China and this method can increase the survival rate of freezing oocytes.It’s easy to carry out,low in cost and high in the recovery rate of oocytes after thawing.