Objective:To explore the pregnancy outcome of intracytoplasmic sperm injection (ICSI)/rescure-ICSI (Re-ICSI) patients with gear-like transparent dense zona pellucida and small perivitelline oocytes.Methods:Totally 6 couples with abnormal zona pellucida came to the Reproductive Medicine Center of Shijiazhuang the Fourth Hospital from January 2015 to June 2020 were retrospectively case control analyzed. A total of 8 cycles had zona pellucida abnormalities, of which 5 couples, the proportion of M I oocytes was ≥50% (part oocytes M I arrest) in 6 cycles and 1 couple (2 cycles) was all oocytes M I arrest. ICSI or in vitro fertilization (IVF) short-term fertilization was performed on M II oocytes with abnormal zona pellucida in controlled superovulation, IVF short-time fertilization failed completely, and Re-ICSI was performed. M I oocytes were performed ICSI/Re-ICSI simultaneously. The ICSI/Re-ICSI fertilization rate, degeneration rate, cleavage rate, high-quality embryo rate and blastocyst rate were compared between the two groups of M II oocytes and M I oocytes, as well as all oocytes M I arrest and part oocytes M I arrest groups, respectively. Results:Totally 37 M II oocytes and 65 M I oocytes underwent ICSI/Re-ICSI. M I oocytes fertilization and 2PN fertilization rates were lower than M II oocytes [46.2%(30/65) vs. 89.2% (33/37); 32.3% (21/65) vs. 83.8% (31/37), all P<0.001]. Both groups had high-quality embryos and blastocyst formation. Compared with part oocytes M I arrest and all oocytes M I arrest, there was no statistical difference in fertilization rate, degeneration rate, high-quality embryo rate and blastocyst formation rate between the two groups (all P>0.05). Conclusion:ICSI/Re-ICSI for patients with abnormal zona pellucida with a high proportion of M I oocytes can increase the patients' oocytes utilization rate and available embryos.

Objective:To explore the pregnancy outcome of intracytoplasmic sperm injection (ICSI)/rescure-ICSI (Re-ICSI) patients with gear-like transparent dense zona pellucida and small perivitelline oocytes.Methods:Totally 6 couples with abnormal zona pellucida came to the Reproductive Medicine Center of Shijiazhuang the Fourth Hospital from January 2015 to June 2020 were retrospectively case control analyzed. A total of 8 cycles had zona pellucida abnormalities, of which 5 couples, the proportion of M I oocytes was ≥50% (part oocytes M I arrest) in 6 cycles and 1 couple (2 cycles) was all oocytes M I arrest. ICSI or in vitro fertilization (IVF) short-term fertilization was performed on M II oocytes with abnormal zona pellucida in controlled superovulation, IVF short-time fertilization failed completely, and Re-ICSI was performed. M I oocytes were performed ICSI/Re-ICSI simultaneously. The ICSI/Re-ICSI fertilization rate, degeneration rate, cleavage rate, high-quality embryo rate and blastocyst rate were compared between the two groups of M II oocytes and M I oocytes, as well as all oocytes M I arrest and part oocytes M I arrest groups, respectively. Results:Totally 37 M II oocytes and 65 M I oocytes underwent ICSI/Re-ICSI. M I oocytes fertilization and 2PN fertilization rates were lower than M II oocytes [46.2%(30/65) vs. 89.2% (33/37); 32.3% (21/65) vs. 83.8% (31/37), all P<0.001]. Both groups had high-quality embryos and blastocyst formation. Compared with part oocytes M I arrest and all oocytes M I arrest, there was no statistical difference in fertilization rate, degeneration rate, high-quality embryo rate and blastocyst formation rate between the two groups (all P>0.05). Conclusion:ICSI/Re-ICSI for patients with abnormal zona pellucida with a high proportion of M I oocytes can increase the patients' oocytes utilization rate and available embryos.