Prognostic value of meiotic spindle imaging on fertilization rate and embryo development in in vitro-matured human oocytes

Objective To evaluate the relationship between spindle visualization and intracytoplasmic sperm injection (ICSI) outcomes in controlled ovarian stimulation (COS) cycles. Design Prospective study. Setting Assisted reproduction center. Patient(s) Thirty patients undergoing ICSI cycles. Intervention(s) Meiotic spindle was evaluated before ICSI in 234 in vivo- and 101 in vitro-matured oocytes Main Outcome Measure(s) Meiotic spindle imaging, fertilization rate, and embryo development. Result(s) Spindle was present in 74.3% and 73.8% of the in vivo- and in vitro-matured oocytes, respectively. Spindle detection rate in oocytes derived from germinal vesicle and metaphase-I stage was, respectively, 50% and 86%. The fertilization rate achieved by the in vivo-matured oocytes was 71.8%, and spindle was detected in 75.6% of the fertilized oocytes and only 34.8.% of the nonfertilized oocytes. In the in vitro-matured oocytes, the fertilization rate was 66.1%, and spindle was detected in 81.4% of the fertilized oocytes and in 59.1% of the nonfertilized oocytes. Ten out of 43 (23.2%) in vitro-matured derived embryos were considered to be high quality, all derived from spindle-detected oocytes, which represents an increase of 13.0% on the overall number of high-quality embryos. Conclusion(s) Meiotic spindle imaging may be useful to predict in vitro-matured oocyte development. However, other factors may contribute to the decreased developmental competence of in vitro-matured oocytes.