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.


METHODS
Retrospective study.


METHODS
Reproductive medicine unit.


METHODS
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).


METHODS
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.


METHODS
Chromosomal status of the analyzed oocytes, development after intracytoplasmic sperm injection, pregnancy, and implantation rates.


RESULTS
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).


CONCLUSIONS
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.
Magli
M Cristina
MC
Reproductive Medicine Unit, Italian Society for the Study of Reproductive Medicine, Bologna, Italy.
Ferraretti
Anna P
AP
Crippa
Andor
A
Lappi
Michela
M
Feliciani
Elisabetta
E
Gianaroli
Luca
L
D000328:Adult; D002470:Cell Survival; D002869:Chromosome Aberrations; D005260:Female; D005307:Fertilization in Vitro; D006801:Humans; D007247:Infertility, Female / Q000235:genetics / Q000473:pathology* / Q000628:therapy; D008540:Meiosis; D008597:Menstrual Cycle; D009865:Oocytes / Q000254:growth & development* / Q000473:pathology*; D010062:Ovulation Induction; D011247:Pregnancy; D011256:Pregnancy Outcome