No abstract

BF represents to a good extent the blastocyst ploidy condition and chromosome status when compared with TE cells. If the proportion of clinically useful BFs is improved, blastocentesis could become the preferred source of DNA for chromosomal testing.

The association between sperm indices and the chromosomal status of preimplantation embryos was assessed in 230 couples with a female partner younger than 36 years undergoing 295 cycles of preimplantation diagnosis for aneuploidy: 105 cycles had normozoospermic samples, 134 cycles presented with oligoasthenoteratozoospermia (OAT), while the remaining cycles had spermatozoa retrieved from the seminal tract due to obstructive (29 cycles) or non-obstructive azoospermia (NOA, 27 cycles). One blastomere was biopsied from day-3 embryos and analysed for chromosomes XY, 13, 15, 16, 17, 18, 21, and 22. From the testing of 1549 embryos, the proportion of chromosomally abnormal embryos was significantly lower in normozoospermic patients (55%) than in OAT (62%, P < 0.025) and NOA patients (69%, P < 0.005). Complex abnormalities were the most frequent defect in NOA (68%), which also demonstrated the highest incidence of gonosomal aneuploidy (12%). From the re-analysis of all blastomeres in 493 non-transferred embryos, 95% of NOA embryos were chaotic mosaics. In conclusion, a severe male infertility condition could contribute to the generation of chromosomal abnormalities in the resulting embryos. This might occur especially in NOA patients in which the high incidence of chromosomal abnormalities is mainly due to mosaicism and gonosomal aneuploidy.

The designed FISH protocol for the analysis of severe OAT and TESE sperm samples is reliable, implying that the studied sample is representative of the original population. In view of the high incidence of aneuploidy in most severe OAT and TESE sperm, the FISH analysis of pathological sperm samples can be routinely performed in order to estimate the chances of the paternal contribution to aneuploidy in the resulting embryos.

BACKGROUNDTo estimate the incidence of aneuploidy in relation to patients' characteristics, the type of hormonal stimulation and their response to induction of multiple follicular growth, 4163 first polar bodies (PB1s) were analyzed.METHODSFive hundred and forty four infertile couples underwent 706 assisted conception cycles (640 with poor prognosis indications and 66 controls) in which chromosomal analysis of PB1 for the chromosomes 13, 15, 16, 18, 21 and 22 was performed. Results were evaluated in a multivariate analysis.RESULTSThe proportion of normal oocytes was directly correlated (P < 0.01) with (i) the number of mature oocytes and (ii) the establishment of a clinical pregnancy; and inversely correlated (P < 0.01) with (i) female age, (ii) causes of female infertility (endometriosis, abortions, ovulatory factor), (iii) poor prognosis indications (female age, number of previous cycles, multiple poor prognosis indications), (iv) number of FSH units per oocyte and (v) number of FSH units per metaphase II oocyte. There was a weak significance of frequency (P < 0.05) between type of abnormality (originated by chromatid predivision, chromosome non-disjunction or combined mechanisms in the same oocyte) and groups of the studied variables, rather than to a specific abnormality or a specific chromosome.CONCLUSIONSThe type of infertility had a significant effect on errors derived from the first meiotic division, whose incidence was significantly higher in the presence of endometriosis or of an ovulatory factor, and in women that experienced repeated abortions. Each aneuploidy event was found to be dependent not on a specific variable, but on groups of variables. In addition, the tendency of chromosomal abnormalities to occur simultaneously implies that the deriving aneuploidies can be of any type.