OBJECTIVE: To clarify the mechanisms underlying oocyte abnormalities in meiosis: meiotic nondisjunction of a whole chromosome or premature separation of sister chromatids in two situations of increased chromosomal risk. DESIGN: Preconception diagnosis by first polar-body analysis in two situations of increased chromosomal risk. SETTING: Departments of reproductive biology, cytogenetics, gynecology, and obstetrics. PATIENT(S): First polar body analysis was proposed to 76 patients (91 cycles) for advanced age (AMA; n = 30, 36 cycles), recurrent implantation failure (RIF; >10 embryos transferred without implantation; n = 32, 36 cycles), or both (AMA + RIF; n = 14, 19 cycles), before their intracytoplasmic sperm injection procedure. INTERVENTION(S): First polar-body analysis using fluorescence in situ hybridization. MAIN OUTCOME MEASURE(S): Mechanisms and frequency of aneuploidy. RESULT(S): Three hundred eighty-four oocytes were analyzed by fluorescence in situ hybridization, 130 from women >38 years of age, 171 from women with RIF, and 83 from women with both indications. The oocyte abnormality rate was similar in the three groups, respectively, 38.5%, 40.4%, and 45.8%. The aneuploidy mechanisms were different for women >38 years of age who had no previous implantation failure (AMA) compared with women of whatever age who had implantation failure (P<.05 vs. RIF; P<.001 vs. AMA+RIF), with, respectively, for the AMA, RIF, and AMA+RIF groups, 72.2%, 56.6%, and 49.2% premature separation of sister chromatids and 27.8%, 43.4%, and 50.8% meiotic nondisjunction. In the two implantation-failure groups, we distinguished a subgroup (22% in the RIF group and 33% in AMA+RIF group) of patients with >2/3 abnormal oocytes, suggesting a meiosis alteration. CONCLUSION(S): The mechanisms accounting for oocyte aneuploidy differed in the two clinical situations of advanced maternal age and RIF. Advanced maternal-age aneuploidy was linked to a loss of sister chromatid cohesion that led to one single chromatid abnormality, whereas implantation failure is a much more heterogeneous situation.
OBJECTIVE: To clarify the mechanisms underlying oocyte abnormalities in meiosis: meiotic nondisjunction of a whole chromosome or premature separation of sister chromatids in two situations of increased chromosomal risk. DESIGN: Preconception diagnosis by first polar-body analysis in two situations of increased chromosomal risk. SETTING: Departments of reproductive biology, cytogenetics, gynecology, and obstetrics. PATIENT(S): First polar body analysis was proposed to 76 patients (91 cycles) for advanced age (AMA; n = 30, 36 cycles), recurrent implantation failure (RIF; >10 embryos transferred without implantation; n = 32, 36 cycles), or both (AMA + RIF; n = 14, 19 cycles), before their intracytoplasmic sperm injection procedure. INTERVENTION(S): First polar-body analysis using fluorescence in situ hybridization. MAIN OUTCOME MEASURE(S): Mechanisms and frequency of aneuploidy. RESULT(S): Three hundred eighty-four oocytes were analyzed by fluorescence in situ hybridization, 130 from women >38 years of age, 171 from women with RIF, and 83 from women with both indications. The oocyte abnormality rate was similar in the three groups, respectively, 38.5%, 40.4%, and 45.8%. The aneuploidy mechanisms were different for women >38 years of age who had no previous implantation failure (AMA) compared with women of whatever age who had implantation failure (P<.05 vs. RIF; P<.001 vs. AMA+RIF), with, respectively, for the AMA, RIF, and AMA+RIF groups, 72.2%, 56.6%, and 49.2% premature separation of sister chromatids and 27.8%, 43.4%, and 50.8% meiotic nondisjunction. In the two implantation-failure groups, we distinguished a subgroup (22% in the RIF group and 33% in AMA+RIF group) of patients with >2/3 abnormal oocytes, suggesting a meiosis alteration. CONCLUSION(S): The mechanisms accounting for oocyte aneuploidy differed in the two clinical situations of advanced maternal age and RIF. Advanced maternal-age aneuploidy was linked to a loss of sister chromatid cohesion that led to one single chromatid abnormality, whereas implantation failure is a much more heterogeneous situation.
Authors: D Molina Gomes; I Hammoud; M Bailly; M Bergere; R Wainer; J Selva; F Vialard Journal: J Assist Reprod Genet Date: 2009-01-28 Impact factor: 3.412
Authors: I Hammoud; F Vialard; M Bergere; M Albert; D Molina Gomes; M Adler; L Malagrida; M Bailly; R Wainer; J Selva Journal: J Assist Reprod Genet Date: 2012-08-14 Impact factor: 3.412
Authors: F Vialard; I Hammoud; D Molina-Gomes; R Wainer; M Bergere; M Albert; M Bailly; P de Mazancourt; J Selva Journal: J Assist Reprod Genet Date: 2008-10-30 Impact factor: 3.412