Impact of assisted hatching on fresh and frozen-thawed embryo transfer cycles: a prospective, randomized study.

The aim of this study was to determine if assisted hatching (AH) could improve the rates of pregnancy and implantation for both fresh and frozen-thawed embryo transfer cycles. A total of 760 fresh embryo transfer cycles and 200 frozen-thawed embryo transfer cycles were randomly assigned to either the treatment group (AH) or the control group (no AH). Zona thinning by laser was performed just before embryo transfer. In fresh embryo transfer cycles, the AH group and control group results were comparable. There were no significant differences in the rates of positive human chorionic gonadotrophin (HCG; 47.5 versus 48.8%), clinical pregnancy (42.4 versus 42.6%), or implantation (26.3 versus 25.2%) between the two groups. However, in frozen-thawed embryo transfer cycles, the rates of positive HCG (32.0 versus 17.0%), clinical pregnancy (25.0 versus 14.0%) and implantation (16.7 versus 7.3%) were significantly greater in the AH group than in the control group (P <: 0.05). The results of this investigation show that in the fresh embryo transfer cycles, laser-assisted hatching by zona thinning has no impact on the rates of positive HCG, clinical pregnancy and implantation, whereas in frozen-thawed cycles, assisted hatching by zona thinning significantly increases all three of these rates.

Exposure to human chorionic gonadotropin during in vitro maturation does not improve the maturation rate and developmental potential of immature oocytes from patients with polycystic ovary syndrome.

OBJECTIVE: To investigate the effects of human chorionic gonadotropin (hCG) in culture medium on the in vitro maturation (IVM) and subsequent developmental potential of human immature oocytes. DESIGN: Prospective, randomized study. SETTING: Reproductive Medicine Center, First Affiliated Hospital of Wenzhou Medical College, People's Republic of China. PATIENT(S): 62 women with polycystic ovary syndrome (PCOS) undergoing IVM treatment. INTERVENTION(S): Immature oocytes were retrieved from unstimulated ovaries of women with PCOS. We tried three different culture systems in this experiment. In group A, oocytes were cultured in the medium containing M199 + 20% fetal bovine serum (FBS) + 75 mIU/mL recombinant follicle-stimulating hormone (FSH) + 0.5 IU/mL recombinant hCG. In group B, oocytes were cultured in hCG-free IVM medium (M199 + 20% FBS + 75 mIU/mL recombinant FSH) for 10 hours, then transferred to the same medium as used for group A. In group C, oocytes were cultured only in hCG-free IVM medium. After the oocytes had matured in vitro, fertilization and embryo transfer were performed. MAIN OUTCOME MEASURE(S): Rates of maturation, fertilization, cleavage, implantation, clinical pregnancy, miscarriage, and live birth. RESULT(S): For groups A, B, and C, the maturation rates at 32 and 48 hours were 46.02% and 69.25%; 43.72% and 64.51%; and 51.87% and 67.51%, respectively. Relatively satisfactory clinical results and implantation rates were obtained in all three groups. No statistically significant differences among groups A, B, and C were found in the rates of maturation, fertilization, cleavage, implantation, clinical pregnancy, miscarriage, or live birth. CONCLUSION(S): The results of our study indicated that the addition of hCG to in vitro culture medium did not improve the maturation rate or development potential of immature oocytes. For the IVM and development of immature oocytes from women with PCOS, hCG appears to be unnecessary.