Objective: To compare the development of abnormal pronuclear zygotes after intracytoplasmic sperm injection (ICSI) and analyze their genetic polymorphism.
Methods: Four hundred and ninety three abnormal pronuclear zygotes after ICSI were divided into three groups based on the number of pronuclei: 347 nonpronuclear oocytes, 71 monopronuclear zygotes and 75 multipronuclear zygotes. All of them were cultured in the medium of Vitrolife G5 series(TM). Sixteen short tandem repeats (STR) of seven blastocysts were then analyzed by ABI3100.
Results: The cleavage rate of nonpronuclear group (25.4%) was lower than that of the others (P<0.01), the proportion of blocked embryos in nonpronuclear group (48.9%) was significantly higher than that of the others (P<0.05), but the blastocyst rate showed no significant difference in three groups (P>0.05). The genetic polymorphism of the 16 STRs showed that the blastocysts from the nonpronuclear and multipronuclear were diploid, and one of the blastocysts from nonpronuclear oocyte was Y-bearing.
Conclusion: The zygotes with abnormal pronuclei after ICSI might have development potential, and the blastocysts from nonpronuclear oocytes and multipronuclear zygotes could be diploid.