Stability of aneuploidy rate in polar bodies in two cohorts from the same patient.

The aim of this study was to evaluate the stability of the aneuploidy rate of the first polar body. Knowing the stability of the oocyte aneuploidy rate for each patient would allow the first analysis to be used as a prognostic tool for further attempts at intracytoplasmic sperm injection (ICSI). After a first unsuccessful ICSI attempt with preconceptional screening, 24 women underwent a second attempt. First polar body aneuploidy rates were compared in the course of two successive ovarian stimulations. The first polar body was biopsied after laser dissection of the zona pellucida and five chromosomes were analysed using the MultiVysion polar body multicolour probe panel. A total of 200 polar bodies were analysed; 91 and 109 in the first and second ICSI attempts, respectively. The total aneuploidy rate was identical in the first and second attempts; 44.0% (40/91) and 44.0% (48/109), respectively. The first evaluation of the aneuploidy rate was statistically (P = 0.0007) correlated with the second, with a correlation coefficient, r = 0.707. The stability of the aneuploidy rate in different cohorts from the same patient, if confirmed in a larger series, makes this parameter a useful tool for counselling couples.

Cytokines and chemokines in follicular fluids and potential of the corresponding embryo: the role of granulocyte colony-stimulating factor.

BACKGROUND: The cytokine/chemokine levels of individual follicular fluids (FFs) were measured to determine whether a biomarker could be linked to the developmental potential of the derived embryo. METHODS: Fluid was collected from 132 individual FFs that were the source of oocytes subsequently fertilized and transferred. In each, a bead-based multiplex sandwich immunoassay (Luminex) was used to measure 28 cytokines and chemokines simultaneously. RESULTS: Significantly higher levels of interleukin (IL-2) and interferon (IFN-gamma) were detected in FF for embryos that underwent early cleavage. IL-12 was significantly higher in FF corresponding to highly fragmented embryos and the chemokine CCL5 was significantly higher in FF related to the best quality (Top) embryos. The level of granulocyte colony-stimulating factor (G-CSF) in individual FF samples was correlated with the implantation potential of the corresponding embryo. The area under the receiver operating characteristics curve, which distinguished the embryos that definitely led to delivery from those that did not, was 0.84 (0.75-0.90) (P = 0.0001) for FF G-CSF. FF G-CSF was significantly lower in patients older than 36 years compared with those <30-year old. When the FF G-CSF was 20 pg/ml or higher, the ratio between Top and non-Top embryos was significantly higher than for the group with FF G-CSF below 20 pg/ml (45 versus 20.45%, P = 0.007). CONCLUSIONS: Individual FF composition is related to the development of the corresponding in vitro generated embryo and its potential of implantation. Individual FF G-CSF may provide a non-invasive biomarker of implantation that needs to be evaluated together with in vitro observation to select the oocyte, and hence the embryo, to transfer.

Oocyte aneuploidy mechanisms are different in two situations of increased chromosomal risk: older patients and patients with recurrent implantation failure after in vitro fertilization.

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.

Evidence of a high proportion of premature unbalanced separation of sister chromatids in the first polar bodies of women of advanced age.

BACKGROUND: Maternal ageing is the only aetiological factor unequivocally linked to aneuploidy. Two mechanisms seem to explain these abnormalities in oocytes: non-disjunction and premature unbalanced separation of sister chromatids (PSSC). Previous studies of unfertilized oocytes argue for a major role of PSSC in the aetiology of aneuploidy for women of advanced age, but in vitro ageing of the oocytes could influence the results. METHODS: Owing to the high prevalence of aneuploidy in women of advanced age, chromosomal screening of the first polar body just before ICSI was offered to women (from 38 years of age) included in an assisted reproduction programme. RESULTS: Among 141 oocytes from 29 women (mean age 40 years and 2 months), 43 (30.5%) were abnormal. Sixty-five abnormalities were found and PSSC was involved in 80% of cases. CONCLUSION: These results are in accordance with previous studies and confirm, in 'fresh' oocytes, the major role of PSSC in the aetiology of aneuploidy in women of advanced age.

[Aging and spermatogenesis: an histologic, cytogenetic and apoptosis study]. / Influence du vieillissement sur la spermatogenèse: évaluation histologique, risque chromosomique et apoptose des spermatozoïdes.

OBJECTIVE: The increase of frequency of Assisted Reproductive Techniques (ART) for elder men raises the question of the genetic risk for the offspring. Our aim was to evaluate the influence of ageing on the testicular histology, the aneuploidy rate in testis postmeiotic cells and the DNA fragmentation in sperm. PATIENTS AND METHODS: We performed a histomorphometric study of 36 men aged from 61 to 102 years and 10 young men from 29 to 40 years. The aneuploidy rate was evaluated by fluorescent in situ hybridation (FISH X, Y, 18) and DNA fragmentation in spermatozoa was evaluated by TUNEL. RESULTS: Histomorphometry showed various alterations of testicular histology with age including thickening of the basal membrane when spermatogenesis was arrested. The number of germinal cells and Sertoli cells decreased with age with important individual variations. Nevertheless spermatogenesis could be possible until 95 years. The rate of aneuploidy was not influenced by age when spermatogenesis was complete. However, we observed an increased aneuploidy rate in postmeiotic cells when spermiogenesis was arrested. On the other hand apoptosis was not increased with age. DISCUSSION AND CONCLUSION: Our study confirms that spermatogenesis is possible until a very advanced age (95 years) without any specific chromosome risk. The question of mutagenesis remains to be solved.

[Genomic instability and male infertility]. / Instabilité génomique et infertilité masculine.

Knowledge of the human genome has opened the genomic era. The genome instability, its causes and the possible consequences especially about fertility start to be understood. This instability can be observed on chromosome structure but also on genes. Different chromosomes rearrangements involved in infertility including translocations and Y chromosome deletions are described. The Y chromosome is a model of instability, and this instability is the source of its evolution. All those rearrangements are the results of illegitimate recombinations between homologous sequences. On genes we find punctual and dynamic mutations, polymorphisms and epigenetic abnormalities. They all are the results of ADN replication mistakes not corrected by the cellular machine. This machinery is the guardian of the genome integrity and in case of abnormality the programmed cellular death is induced. The knowledge of all these instability mechanisms is essential to appreciate the risk for the offspring after intracytoplasmic sperm injection. Indeed we go round physiological barriers without a complete understanding of the mechanisms involved. Thus, this is an important challenge for research teams but also for all assisted reproduction centers, dealing with ART. Genome is unstable - the very basis of its evolution. But this is also the cause of mistakes with pathological consequences like infertility and mental retardation.

An idiopathic infertility with oocytes metaphase I maturation block: case report.

BACKGROUND: A case of idiopathic primary infertility was attributed to a block in oocyte meiosis affecting the transition between metaphase I and metaphase II. METHODS AND RESULTS: A couple suffering unexplained primary infertility was unsuccessfully treated by various means of assisted reproductive technology. After four unsuccessful pregnancy attempts using intrauterine inseminations (IUI), IVF was attempted (all oocytes remained unfertilized), followed by an ICSI cycle. None of the retrieved oocytes expelled the polar body, and therefore were not injected. The failure of these assisted reproduction cycles was, in both cases, due to the immaturity of the oocytes recovered. Cytogenetic analysis of the oocytes retrieved for ICSI provided evidence of meiotic arrest. Using cytogenetic staging criteria we were able to show that this arrest occurred between metaphase I and anaphase I. CONCLUSIONS: Meiotic blocks affecting oocytes have already been described for various mammals. We discuss here mechanisms that might be involved in this possibly inherited disorder in humans, and ways in which our knowledge of them could be increased.

[Prognostic sperm factors in intra-uterine insemination with partner's sperm]. / Facteurs pronostiques spermatiques des inséminations intra-utérines avec sperme du conjoint.

We studied the prognostic value of sperm characteristics for the outcome of intra-uterine insemination with partner sperm (IUIPS). A total of 712 cycles of IUIPS following induction of ovulation with gonadotrophin (hMG/hCG) for 277 sterile couples attending the assisted reproductive technology centre of Poissy Hospital (78300-France) between January 1991 and December 1994 was studied retrospectively. Ninety-two clinical pregnancies were obtained giving an overall rate of 12.9% per cycle. None of the characteristics of the sperm as assessed initially correlated with outcome. In contrast, the number of motile spermatozoa given (n) affected outcome: for n < 1 x 10(6) the pregnancy rate was 2%; for n = 5 to 8 x 10(6) the rate was 19%. However, for +/- 8 x 10(6) the proportion of biochemical pregnancies and miscarriages was 40% which was significantly higher than for smaller concentration. The resort of IVF following 4 IUIPS failures leads to a pregnancy rate per cycle of only 6.7%.

Prospective randomized comparison of intrauterine and intracervical insemination with donor spermatozoa.

From March 1990 to September 1993, 20 women underwent a total of 89 cycles of intracervical inseminations with donor semen (ICI) and 23 women underwent 67 cycles of intrauterine inseminations with donor semen (IUI). The women were assigned to the two groups randomly, but ensuring that the ages of the women and pathologies of the male partner (azoospermia or severe oligozoospermia) were similar in the two groups. There was no significant difference between the characteristics of the two groups and the method used to induce ovulation (HMG/HCG) was identical. Two semen straws were used for each insemination cycle. Semen was prepared for IUI on a Percoll gradient. Thirteen clinical pregnancies were obtained in the IUI group (19.4% of the attempts) and six in the ICI group (6.75%). After six cycles of insemination, 75.4% of the women of the IUI group obtained a pregnancy, as compared to 35% in the ICI group. These good results may be due to the method of induction of ovulation, but also to the technique itself, increasing the number of motile spermatozoa at the site of fertilization. The time taken to obtain a pregnancy is thus shorter with IUI than with ICI, and the number of semen straws required is smaller. In-vitro fertilization (IVF) should be proposed after six failures by IUI.