Abstract:

Objective To evaluate the development of human embryos by morphology discrepancies of oocyte at metaphase Ⅱ (MⅡ) of the first polar body and pronucleus. Methods The 269 infertile couples (269 transfer cycles) who treated with intracytoplasmic sperm injection (ICSI） from June 2009 to June 2012 in the First Affiliated Hospital of Guangxi Medical University were selected. Oocytes at MⅡ were classified by the morphology of first polar body and pronucleus zygotes were classified by the Scott scoring system. Fertilization rate, cleavage rate, and good quality embryo rate of each type of oocytes and zygotes were campared. Results According to different grades of first polar body and pronucleus zygote, embryos were divided into group A (69 cases), group B (102 cases), and group C (98 cases). The embryos of oocytes (1-2 grade) and pronucleus (Z1-Z2 grade) had higher fertilization rate, cleavage rate, good quality embryo rate, implantation rate, and pregnancy rate. Conclusion The higher the grade of oocyte at metaphase Ⅱ of first polar body and pronucleus, the better potential of human embryo development. So this can increase the implantation and pregnancy rate of intracytoplasmic sperm injection/embryo transplantation.

Key words: metaphase Ⅱ oocyte, morphology of first polar body, pronuclei morphology, implantation rate, pregnancy rate, embryo development potention