The Relationship of Pronuclear Stage Morphology and Chromosome Status at Cleavage Stage

摘要

>Purpose>: Infertile couples undergoing in vitro fertilization-embryo transfer (IVF-ET) program were included to study the relationship of pronuclear stage morphology and chromosome status at cleavage stage.>Methods>: Eighteen to twenty-one hours after fertilization, zygotes were checked for pronuclear morphology with modified Scott Z-score system. After embryo transfer on day 3, arrested or non-transferred 2 PN embryos were spread for fluorescence in situ hybridization (FISH) staining of probes to chromosomes 18, X and Y.>Results>: Ninety-eight embryos were successfully fixed and stained. The chromosome status were recorded in each 2 PN score group: 7 (54%) of 13 embryos in Z2 group, 14 (35%) of 40 in Z3 group and 10 (36%) of 28 in Z4 group being normal diploid. Z1 group has 12 (71%) of 17 embryos being normal diploid, which is significantly more than Z3 (p=0.020) and Z4 group (p = 0.033).>Conclusion>: Our results demonstrated a high probability to get normal diploid embryos if good morphology at pronuclear stage was used as selection criteria, especially for Z1 score embryos.