In mammalian oocytes, the maintenance of meiotic prophase I arrest prior to the surge of LH that stimulates meiotic maturation depends on a high level of cAMP within the oocyte. In mouse and rat, the cAMP is generated in the oocyte, and this requires the activity of a constitutively active, Gs-linked receptor, GPR3 or GPR12, respectively. To examine if human oocyte meiotic arrest depends on a similar pathway, we used RT-PCR and Western blotting to look at whether human oocytes express the same components for maintaining arrest as rodent oocytes. RNA encoding GPR3, but not GPR12, was expressed. RNA encoding adenylate cyclase type 3, which is the major adenylate cyclase required for maintaining meiotic arrest in the mouse oocyte, was also expressed, as was Galphas protein. To determine if this pathway is functional in the human oocyte, we examined the effect of injecting a function-blocking antibody against Galphas on meiotic resumption. This antibody stimulated meiotic resumption of human oocytes that were maintained at the prophase I stage using a phosphodiesterase inhibitor. These results demonstrate that human oocytes maintain meiotic arrest prior to the LH surge using a signaling pathway similar to that of rodent oocytes.
The aim of this retrospective study was to evaluate the effectiveness of gonadotrophin-releasing hormone agonist (GnRHa) to trigger oocyte maturation in patients with polycystic ovarian syndrome (PCOS) or previous high response. The outcome of ovarian stimulation and IVF in patients using GnRHa to trigger oocyte maturation after co-treatment with GnRH antagonist (study group) was compared with patients using human chorionic gonadotrophin (HCG) to trigger oocyte maturation after a dual pituitary suppression protocol with oral contraceptive pill (OCP) and GnRHa overlap (control group). All patients received intramuscular progesterone for luteal support but patients in the study group received additional supplementation with oestradiol patches. The mean number of oocytes, proportion of mature oocytes and fertilization rate were similar between the study and control groups. Implantation rate (38.6% versus 45.1%), clinical pregnancy rate (69.6% versus 60.9%) and delivery rate (62.5% versus 56.5%) were similar in the study and control groups respectively. There was one case of moderate ovarian hyperstimulation syndrome (OHSS) in the control group and none in the study group. GnRHa is effective in triggering oocyte maturation in patients with PCOS or previous high response. Further randomized studies are required to evaluate its effectiveness in the prevention of OHSS in this group of patients.
Purpose The aim of this study was to analyze the outcomes of IVF/ICSI cycles in women aged 43 and beyond. Methods Retrospective analysis of clinical pregnancy and live birth rates in168 fresh, non donor, ART cycles performed in two Connecticut university IVF programs. Results In women of 43 and 44 years the overall clinical pregnancy and live birth rates were 8.3 % and 5.3 % per initiated cycle, respectively. There were no clinical pregnancies in women ≥45 years old. First cycle characteristics were not different from repeated cycles in terms of duration of ovulation induction, number of collected oocytes and transferred embryos (p>0.05). Conclusions Pregnancies can still be achieved with IVF/ICSI up to the age of 44. Since most pregnancies occurred within the first 3 cycles, another attempt may be a reasonable option before resorting to oocyte donation for patients who failed two previous cycles. Women 45 years and beyond do not benefit from ART procedures using their own oocytes.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.