Sir, It has been more than 10 years since safe and effective gonadotrophinreleasing hormone (GnRH) antagonists became available for use in controlled ovarian stimulation (COS) cycles. In 2000, we noted that there was an inconsistency with how researchers in this field describe the mechanism of action of GnRH antagonists (Mannaerts and Gordon, 2000). Unfortunately, there is continued misuse of t...

Close to 30 forms of gonadotropin releasing hormone (GnRH) and at least five GnRH receptors have been identified in a wide variety of vertebrates and some invertebrates. One form, now called GnRH II, has the broadest distribution and the most ancient and conserved phylogeny. The distribution of the neurons that produce this peptide are completely nonoverlapping with any other GnRH forms. Fibers...

OBJECTIVE We devised a novel strategy, a GnRH antagonist protocol with a GnRH agonist trigger followed by frozen-thawed blastocyst transfers with long zona dissection (LZD). The purpose of this study was to investigate the clinical outcomes of this new strategy according to age. METHODS Ninety women aged less than 35 (group A) and 32 women aged 35 to 39 (group B) underwent the GnRH antagonist...

BACKGROUND Although a large number of studies have been conducted in relation to ovarian response and pregnancy after GnRH agonist and GnRH antagonist controlled ovarian hyperstimulation protocols, most of them used single or combinations of a few predictive factors, and none included the stimulation protocol in the multivariable analysis. The present study was thus primarily designed to invest...

In our previous studies, we demonstrated that ERK1/2 (extracellular signal-regulated protein kinase) and p38 MAPK (mitogen-activated protein kinase) are required for gonadotropin-releasing hormone (GnRH)-II-induced anti-proliferation of ovarian cancer cells. In the present study, we examined the role of the GnRH-I receptor, as well as the activation of protein kinase C (PKC), in the anti-prolif...

BACKGROUND Highly purified hMG (hp-hMG) has recently shown better cycle outcome than the recombinant FSH (rFSH) when compared in GnRH agonist long protocol cycles. However, they have not yet been compared in GnRH antagonist cycles. METHODS A RCT comparing the ongoing pregnancy rate (primary end-point) in 280 patients undergoing IVF/ICSI after stimulation with hp-hMG or rFSH controlled with a ...

Abstract Study question Can progestins be used to prevent spontaneous LH surge during ovarian stimulation (OS) without affecting the euploid blastocyst rate (EBR) per metaphase-II (MII) oocytes? Summary answer Progestin Primed Ovarian Stimulation (PPOS) (conducted with norethisterone acetate) and conventional-OS GnRH-antagonist show similar EBR MII-oocytes What is known already PPOS a novel OS ...

Two forms of gonadotropin-releasing hormone (GnRH), GnRH-I and GnRH-II, are commonly present in mammals. The main hormone controlling reproduction is GnRH-I acting through its receptor (GnRHR-I), whereas the function of GnRH-II is unknown. In primates, it has been suggested that GnRH-II is a specific agonist for the structurally distinct GnRHR-II. Here we compared effects of GnRH-I and GnRH-II ...

If ovarian stimulation is performed accordingly to new strategies available, the occurrence of ovarian hyperstimulation syndrome will be eradicated. The strategy is to stimulate all women with GnRH antagonist and in case of need to -induce final egg maturation with GnRH agonist.

Volume 1 | Issue 1 Abstract A monoclonal antibody (Mab) designated as GHR106 was generated against the extracellular domain (N1-29 synthetic peptide) of human gonadotropin releasing hormone (GnRH) receptor. It is a first-in-class GnRH analog and can serve as a drug candidate for potential applications in the treatment of human cancers and/or fertility regulations. Both Mabs in murine (mGHR106) ...