EFFECTS OF 1,2-PROPANEDIOL AND FREEZING-THAWING ON THE IN-VITRO DEVELOPMENTAL CAPACITY OF HUMAN IMMATURE OOCYTES

Objective: To investigate effects of 1,2-propanediol and freezing-thaw ing treatment on the maturation and developmental capacity of the huma n immature oocytes obtained from unstimulated ovaries. Design: Intact cumulus-enclosed immature oocytes collected from unstimulated ovaries were divided into three groups, such as no treatment as control (group 1), only 1,2-propanediol-treated (group 2), and cryopreserved group ( group 3). Oocytes in group 1, group 2, and survived oocytes from cryop reservation in group 3 were cultured for 48 hours. A random selection of matured oocytes was inseminated with normal donor sperm to evaluate the fertilization and developmental capacity. Setting: Infertility Me dical Center at the CHA General Hospital, Seoul, Korea.Patient(s): Ooc ytes were obtained from patients undergoing gynecological surgery. Mai n Outcome Measure(s): Rates of survival, maturation to metaphase II, f ertilization, and cleavage. Result(s): Survival rate after freezing-th awing in group 3 was 55.1% (54/98). Oocytes were cultured in Dulbecco' s modified Eagle's medium (DMEM) supplemented with 20% fetal bovine se rum, 10 IU/mL pregnant mare serum gonadotropin, and 10 IU/mL hCG. Matu ration rates were 76.8% (63/82), 67.1% (47/70), and 59.3% (32/54) in t he groups 1, 2, and 3, respectively. Maturation rate in group 3 was si gnificantly lower than that of group 1. Fertilization rates were 90.5% (19/21), 81.0% (17/21), and 42.9% (6/14), and cleavage rates were 94. 7% (18/19), 88.2% (15/17), and 16.7% (1/6) in groups 1, 2, and 3, resp ectively. Fertilization and cleavage rates of survived oocytes in grou p 3 also were significantly lower than those of groups 1 and 2. Conclu sion(s): Results suggest that the pretreatment with 1.5 M 1,2-propaned iol itself before the freezing has no inhibitory effect on the maturat ion, fertilization, and cleavage of human immature oocytes in vitro. H owever, the freezing-thawing procedure used had detrimental effects on the maturation and developmental capacity.