Publications (4)9.5 Total impact

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    ABSTRACT: Only 50-60 % of immature human oocytes attain the mature stage in vitro. Such a deficiency may be a reflection of inadequate conditions of in vitro maturation (IVM) or a manifestation of intrinsic oocyte defects. In the present study, we explored the possibility that the DNA of immature oocytes may be damaged and that such a condition, or inability to trigger a repair action, is associated to germinal vesicle (GV) arrest. Immature oocytes (GV-stage oocytes) were obtained from women undergoing stimulated (Stim-C) or IVM (IVM-C) cycles. GV oocytes obtained from stimulated cycles were fixed for successive analysis either after recovery (T0) or following 30 h (T30) of culture if still arrested at the GV stage. Oocytes retrieved in IVM cycles were used only if they were found arrested at the GV stage after 30 h (T30) of culture. All oocytes were fixed and stained to detect chromatin and actin. They were also assessed for positivity to γH2AX and Rad51, markers revealing the presence of double-strand DNA breaks and the activation of a DNA repair response, respectively. Labelled oocytes were analysed using a Leica TCS SP2 laser scanning confocal microscope. In Stim-C oocytes, γH2AX positivity was 47.5 and 81.5 % in the T0 and T30 groups, respectively (P = 0.003), while γH2AX-positive oocytes were 58.3 % in the IVM-C T30 group (Stim-C T0 vs. IVM-C T30, P = 0.178; Stim-C T30 vs. IVM-C T30, P = 0.035). Positivity for nuclear staining to Rad51 occurred in 42.1 and 74.1 % of Stim-C in the T0 and T30 subgroups, respectively (T = 0.006), while 66.7 % of IVM-C T30 oocytes resulted positive for a DNA repair response (Stim-C T0 vs. IVM-C T30, P = 0.010; Stim-C T30 vs. IVM-C T30, P = 0.345). The present data document the existence of double-strand DNA breaks (DSBs) in human immature oocytes. Also, they are consistent with the hypothesis that insults to DNA integrity may be an important factor affecting meiotic resumption.
    Journal of Assisted Reproduction and Genetics 08/2015; DOI:10.1007/s10815-015-0547-6 · 1.77 Impact Factor
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    ABSTRACT: To assess retrospectively the developmental potential of different types of cumulus cell-oocyte complexes (COCs) derived from IVM cycles. IVM cycles were performed in natural cycles or after HCG, FSH, or FSH/HCG priming. COCs recovered were morphologically characterized in different types: compact (CC) or expanded (EC) cumulus mass but including an immature oocyte, and expanded cumulus mass enclosing a mature oocyte (EC-MII). Embryo developmental competence was investigated analysing exclusively cycles in which all transferred embryos derived from the same COC category. Fertilization rates did not differ significantly. Significant differences in pregnancy rates (14.5%, 10.0% and 27.6 % in the CC, EC, and EC-MII categories, respectively) were observed. Likewise, significant differences in implantation rates (8.9%, 6.3% and 19.1% in the CC, EC, and EC-MII categories, respectively) were found. Overall, priming with FSH/HCG had a beneficial effect on pregnancy and implantation rates, while no priming or HCG alone generated oocytes with poor competence. In IVM cycles, morphological evaluation at the time of collection can predict the developmental ability of different COCs. FSH/HGC priming has a positive effect on oocyte competence.
    Journal of Assisted Reproduction and Genetics 04/2012; 29(6):513-9. DOI:10.1007/s10815-012-9766-2 · 1.77 Impact Factor
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    ABSTRACT: This study was designed to determine if the efficiency of in-vitro maturation (IVM) in women with normal ovaries can be improved by gonadotrophin administration. 400 women were randomly allocated in four groups: group A, non-primed cycles; group B, human chorionic gonadotrophin (HCG)-primed cycles; group C, FSH-primed cycles; and group D, FSH- plus HCG-primed cycles. There were significant differences in the IVM rate among the groups. In groups where HCG was used, the overall maturation rate was higher (57.9% in group B and 77.4% in group D; 48.4% in group A and 50.8% in group C) and the percentage of total available metaphase II-stage oocytes was higher (60.4% in group B and 82.1% in group D; 48.4% in group A and 50.8% in group C). The overall clinical pregnancy rate per transfer (CPR) was 18.3% and the implantation rate (IR) was 10.6%. There was a difference in CPR among the groups: group D (29.9%) versus group A (15.3%), P = 0.023; group D versus group B (7.6%), P < 0.0001; group D versus group C (17.3%), P = 0.046. The results of this study are clearly in favour of FSH plus HCG priming. FSH priming and HCG priming alone showed no significant effects on clinical outcome.
    Reproductive biomedicine online 09/2009; 19(3):343-51. DOI:10.1016/S1472-6483(10)60168-X · 2.98 Impact Factor
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    ABSTRACT: The in-vitro maturation protocol (IVM) is an intriguing tool in assisted reproduction since it omits the side-effects of drug stimulation and reduces the cost of the entire procedure, both in terms of time and patient/society costs. In the Biogenesi Reproductive Medicine Centre, the IVM technique has been applied for more than 3 years, obtaining successful results in terms of maturation and fertilization rates, number of pregnancies and healthy babies born. At present, IVM is widely accepted in polycystic ovary and polycystic ovarian syndrome patients but its application in other women is still controversial. This study has been carried out in order to determine the efficiency of unstimulated IVM in women with morphologically and endocrinologically normal ovaries. Body mass index, basal FSH and oestradiol concentrations, antral follicle count, endometrial thickness and lead follicle size were correlated with the outcome of the procedure so as to obtain useful criteria to select women with regular cycles for an IVM technique. It was found that basal oestradiol concentration, FSH concentration and antral follicle count are useful criteria in deciding whether to start and continue the procedure, while lead follicle size and endometrial thickness are important criteria in deciding the timing of oocyte retrieval.
    Reproductive biomedicine online 03/2009; 18(2):251-61. DOI:10.1016/S1472-6483(10)60263-5 · 2.98 Impact Factor