The aim of the present prospective study was to obtain quantitative data on endometrial volume by three-dimensional (3D) ultrasound at the time of embryo transfer in an in-vitro fertilization programme and to assess its value in predicting endometrial receptivity. The cycles (n = 72) were classified according to endometrial volume: group A <2 ml, group B 2-4 ml, and group C >4 ml. Comparisons of the groups showed that pregnancy and implantation rates were significantly lower (P < 0.05) in the group of patients with an endometrial volume <2 ml. Furthermore, no pregnancy was achieved with an endometrial volume <1 ml. It is concluded that endometrial volume by 3D transvaginal ultrasound may become a new objective parameter by which to predict endometrial receptivity.

GnRH is one of the paracrine/autocrine regulators of hCG secretion produced by the human trophoblast during pregnancy. We hypothesized that GnRH may play a role in the embryonic/endometrial dialogue during early implantation. To examine this hypothesis, we assessed GnRH and GnRH-receptor mRNA and protein expression in human endometrium throughout the menstrual cycle of premenopausal fertile patients. Quantitation of the mRNA was performed by reverse transcription (RT)-competitive polymerase chain reaction (PCR) in the presence of a competitive cDNA fragment. RT-PCR revealed that unfractioned endometrium and isolated endometrial stromal and epithelial cells express GnRH and GnRH-receptor mRNA throughout all phases of the menstrual cycle. Quantitative PCR showed a dynamic pattern in the GnRH mRNA expression throughout the cycle, with a significant increase (p < 0.05) in the secretory phase as compared to the proliferative phase. Furthermore, quantitative competitive PCR of isolated glandular and stromal cells showed higher mRNA levels (p < 0.05) in the luteal phase in both compartments. GnRH immunostaining was localized in all major compartments, with the most intense staining during the luteal phase. On the basis of these data, we suggest that during reproductive life, endometrial GnRH may play a paracrine/autocrine role in the early stages of implantation by modulating embryonic trophoblastic secretion of hCG.

Gonadotrophin-releasing hormone (GnRH) regulates gonadotrophin biosynthesis and release in the anterior pituitary via specific receptors. Extrapituitary expression and action of GnRH have been demonstrated in several species. A possible role for GnRH in preimplantation embryonic development, endometrial preparation, and the implantation process has been previously suggested. Moreover, the presence of an immunoreactive GnRH in preimplantation embryos has been demonstrated in different species; however, there are no data for human embryos. We postulate that in humans GnRH may play a role in preimplantation embryonic development as well as in the implantation process. To examine this hypothesis, we assessed GnRH and GnRH-receptor mRNA and protein expression in human preimplantation embryos with three pronuclei. GnRH is expressed in peri-implantation human embryos at both the mRNA and protein level. GnRH-receptor mRNA is also present in the embryos studied. Immunohistochemical localization of GnRH showed intense staining in all the blastomeres at morula stage as well as in the trophectoderm and inner cell mass of the blastocysts. The results of the present study challenge the widely held view that GnRH has a predominantly central action, and suggests a pathway to describe a local role for the GnRH system in successful preimplantation embryonic development and implantation.

A total of 30 young infertile patients who exhibited a poor response in two previous consecutive cycles, despite having normal basal follicle stimulating hormone (FSH) and oestradiol concentrations, were invited to participate in a prospective randomized study comparing the clinical efficacy of recombinant (rFSH) and urinary (uFSH) follicle stimulating hormone. An evaluation of the total dose used (3800 IU versus 4600 IU, P < 0.05) and duration of treatment (10.2 days versus 13.2 days, P < 0.05) showed a significantly shorter treatment period as well as a significantly lower total dose of FSH required to induce ovulation successfully in the group of patients treated with rFSH. Significantly more oocytes (7.2 versus 5. 6, P < 0.05) as well as mature oocytes (5.9 versus 3.2, P < 0.01) were retrieved after rFSH treatment. In addition, significantly more good quality embryos were obtained (3.4 versus 1.8, P < 0.05) in the group of patients treated with rFSH and, as a result, higher pregnancy (33 versus 7%, P < 0.01) and implantation (16 versus 3%, P < 0.01) rates were achieved in these patients. It is concluded that rFSH is more effective than uFSH in inducing multifollicular development and achieving pregnancy in young low responders.