The glandular cells of the human endometrium express GH from the late luteal phase throughout pregnancy in the decidual tissue. We suppose that GH plays an important role in blastocyst implantation.
In this study the solubility to α-chymotrypsin of the zona pellucida (ZP) of human oocytes and polyploid embryos obtained during various clinical procedures of assisted fertilisation (IVF, ICSI, cyropreservation) was evaluated. The aim of the study was to determine whether changes in ZP solubility occur during such procedures and whether abnormal solubility could be likened to fertilisation failure. Correlation between ZP solubility and cortical granule (CG) density was also studied. The results showed that ZP solubility varied considerably among germinal vesicle or metaphase oocytes obtained from different subjects, but was essentially identical for the oocyte cohort obtained from individual women. On the basis of ZP solubility metaphase oocytes were subdivided into two classes: class I, average ZP dissolution time ± SE = 24.1 ± 0.9 min, n = 28; and class II, 46.7 ± 2.0 min, n = 13. Prolonged ZP dissolution times of metaphase oocytes were significantly correlated with a low in vitro fertilisation rate in sibling oocytes. The zonae of fertilised eggs (polyploid embryos) showed long solubilisation times (IVF: 45.3 ± 3.4 min, n = 18; ICSI: 48.9 ± 2.7 min, n = 19). ZP solubility of oocytes that failed to fertilise was intermediate between that of class I metaphase oocytes and embryos (unfertilised IVF: 33.0 ± 2.7 min, n = 13; unfertilised ICSI: 43.0 ± 2.4 min, n = 9). A moderate spontaneous ZP hardening occurred when metaphase oocytes were cultured for 24 h. Finally, cryopreservation of unfertilised oocytes caused hardening of their ZP, with dissolution times that were comparable to those found in fertilised eggs (49.5 ± 2.3 min, n = 10). In most cases, an inverse correlation was found between ZP dissolution time and CG density (longer solubilisation times corresponding to lower CG density). ZP hardening caused by cryopreservation, however, was not associated with a significant reduction in CG density in most of the oocytes examined.
Follicle development is controlled amongst other factors by pituitary gonadotropins follicle-stimulating hormone (FSH) and luteinizing hormone (LH) that act in synergy in completing follicle maturation. Exogenous gonadotropins, combined with gonadotropin-releasing hormone agonists, have been successfully used in patients with ovulatory disorders undergoing assisted reproduction. There is some evidence of a beneficial role of androgens or LH administration before FSH stimulation. This study was designed to verify whether the addition of LH in the early follicular phase, in downregulated patients undergoing follicular stimulation for assisted reproduction, would add benefits in terms of general outcomes and pregnancy rates. We compared two groups of patients one of which was treated with recombinant FSH (rFSH) alone and the other with rFSH plus recombinant LH (rLH), in the early follicular phase only. The number of eggs recovered was higher in the group treated with FSH only; however, the number of embryos available at transfer was similar in the two groups and, more importantly, the number of Grades I and II embryos was higher in the group pretreated with LH. Similarly, although biochemical pregnancy rate and clinical pregnancy rates were similar in both groups, a beneficial role of LH priming was demonstrated by the higher implantation rate achieved in these patients.
Granulocyte-macrophage colony-stimulation factor plays different crucial roles during embryo implantation and subsequent development. Here we aimed to evaluate the effects of embryo cell culture medium, with the inclusion of granulocyte-macrophage colony-stimulation factor (GM-CSF), on embryo development and pregnancy rate. To this end, we took advantage of our retrospective observational study to correlate the outcomes from two different culture media. We included in this study 25 unselected patient from our IVF Center that underwent heterologous IVF cycle with crypreserved oocytes. We analyze the fertilization rate, pregnancy rate, and embryo quality at different day of transfer obtained from two different media composition. Our results show that the rate of fertilization and the pregnancy rate were increased using medium added with this particular type of cytokines (GM-CSF).
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