Embryo developmental potential of microsurgically corrected human three-pronuclear zygotes

Abstract

We explored the embryo development potential of human three-pronuclear (3PN) zygotes reduced to two-pronuclear (2PN) zygotes (3 → 2PN zygotes) by micropuncture. In this study, there were three groups, the 3 → 2PN group (338 zygotes), the non-corrected 3PN group (381 zygotes), and the normal 2PN group (359 zygotes). The first cleavage mode (2-cell cleavage or 3-cell cleavage), 6-8 cell embryogenesis rate, high-quality embryogenesis rate and Day 5/Day 6 blastulation rate were compared between the three groups. The success rate of enucleation was 92.9%. The 2-cell cleavage rate was significantly higher in the 3 → 2PN group (74.3%) than in the 3PN group (36.4%) (P < 0.05), but had no statistical difference compared with the 2PN group (86.0%) (P > 0.05). The 6-8 cell embryogenesis rate was significantly higher in the 3 → 2PN group (91.1%) as compared to the 2PN group (85.6%) (P < 0.05), but had no statistical difference compared with the 3PN group (95.0%) (P > 0.05). Total blastulation rate was significantly higher in the 2PN group (58.8%) as compared to the 3PN group (21.5%) (P < 0.01), and in the 3 → 2PN group as compared to the 3PN group (5.6%) (P < 0.01). Also D5 blastulation rate was significantly higher in the 2PN group (53.7%) as compared to the 3 → 2PN group (8.9%) (P < 0.01), and in the 3 → 2PN group as compared to the 3PN group (1.9%) (P < 0.01). In 3 → 2PN zygotes, the first cleavage mode is mainly 2 cells which is significantly higher than that in 3PN zygotes. Compared with 3PN zygotes, the embryo developmental potential of 3 → 2PN zygotes is improved, but still is lower than that in 2PN zygotes.

Influence of endometrial thickness on treatment outcomes following in vitro fertilization/intracytoplasmic sperm injection

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The Impact of Endometrial Thickness on the Day of Human Chorionic Gonadotrophin (hCG) Administration on Ongoing Pregnancy Rate in Patients with Different Ovarian Response

“…Cleavage stage embryos were divided into 4 grades in our center [ 13 ]. Embryos scored with Grade I or Grade II were considered to be high quality embryo.…”

Functional Analysis of Human Pathological Semen Samples in an Oocyte Cytoplasmic Ex Vivo System

“…up to blastocyst formation. Approximately 25% of the oocytes injected with a sperm arrest their development at day 1 due to fertilization errors 3 , 4 while 25–30% of the remaining embryos are lost in culture during the first days of in vitro development 5 , 6 . Although some factors affecting embryo development, such as complex aneuploidies and severe sperm DNA fragmentation, have been identified, the systematic characterization of possible causes of embryo loss, at the molecular level, has been hampered by ethical and technical issues alike.…”