Biomedical subjects

Michela Lappi

Publications and source records attributed to Michela Lappi.

2 recordsLinked to original sources

PubMed2006

Embryo morphology and development are dependent on the chromosomal complement.

OBJECTIVE: To analyze embryo morphology in relation to the corresponding chromosomal status, in order to evaluate the effects of aneuploidy over fragmentation, delayed cleavage, and arrested cleavage. DESIGN: Retrospective study. SETTING: Reproductive Medicine Unit, Società Italiana di Studi di Medicina della Riproduzione, Bologna, Italy. PATIENT(S): A total of 662 patients with a poor prognosis for pregnancy underwent 916 cycles of preimplantation genetic diagnosis for aneuploidy. INTERVENTION(S): The chromosomes XY, 13, 15, 16, 18, 21, and 22 were analyzed in blastomeres biopsied from day 3 embryos. MAIN OUTCOME MEASURE(S): Embryo morphology, chromosomal status of the analyzed blastomeres, and spreading and reanalysis of nontransferred embryos. RESULT(S): The incidence of chromosomal abnormalities was significantly higher in arrested or slow-cleaving embryos, and in embryos cleaving too fast, compared to embryos with eight cells at 62 hours after insemination. The presence of an uneven number of blastomeres or fragments scattered in the perivitelline space was associated with an increased incidence of chromosomal abnormalities. CONCLUSION(S): A correlation between embryo development and chromosomal complement makes the incidence of chromosomal abnormalities significantly higher in embryos dividing according to a time frame and a symmetry plan which are different from what are expected. The type of fragmentation is also related to chromosomal status, which explains why the extrusion of fragments might severely affect embryo viability.

Adult↗

PubMed2006

First meiosis errors in immature oocytes generated by stimulated cycles.

OBJECTIVE: To investigate chromosomal errors detected by first polar body (PB) biopsy in relation to the nuclear maturity of the oocytes. DESIGN: Retrospective study. SETTING: Reproductive medicine unit. PATIENT(S): Eighty-seven cycles were examined by PB biopsy for aneuploidy. Indications were maternal age >or=38 years (49 cycles), repeated IVF failures (22 cycles), and others (16 cycles). INTERVENTION(S): First polar bodies were analyzed for the chromosomes 13, 16, 18, 21, and 22 in both in vivo and in vitro matured oocytes. Euploid oocytes were inseminated by intracytoplasmic sperm injection. MAIN OUTCOME MEASURE(S): Chromosomal status of the analyzed oocytes, development after intracytoplasmic sperm injection, pregnancy, and implantation rates. RESULT(S): In in vitro matured oocytes, the proportion of chromosomal abnormalities was higher than in in vivo matured oocytes (70% vs. 54%, P<.005), with complex abnormalities being the prevailing defect (62% vs. 40%, P<.001). Conversely, the presence of an extra chromatid or the lack of a chromatid was more frequent in in vivo than in in vitro matured oocytes (55% vs. 34%, P<.001). CONCLUSION(S): The low viability of in vitro matured oocytes from stimulated cycles could be related to a significantly higher proportion of chromosomal abnormalities compared with in vivo matured oocytes. Complex abnormalities, involving two or more chromosomes, gave the strongest contribution to the detected increase.

Adult↗