Current ovarian stimulation regimens for IVF are complex and not without risk. Increasing our knowledge of the physiology of follicle development and dominant follicle selection may enable the design of less complex, safer and cheaper ovarian stimulation regimens for IVF. Decremental serum FSH concentrations during the follicular phase of the menstrual cycle are required for single dominant fol...

The estrous cycle of mono-ovulatory species such as cows or humans, is known to show two or more waves of follicular growth and decline between two successive ovulations. Within each wave, there is one dominant follicle escorted by subordinate follicles of varying number. Under the surge of the luteinizing hormone a growing dominant follicle ovulates. Rarely the number of ovulating follicles ex...

Most estrous cycles in cows consist of 2 or 3 waves of follicular activity. Waves of ovarian follicular development comprise the growth of dominant follicles some of which become ovulatory and the others are anovulatory. Ovarian follicular activity in cows during estrous cycle was studied with a special reference to follicular waves and the circulating concentrations of estradiol and progestero...

BACKGROUND In anovulatory women undergoing ovulation induction, addition of recombinant human LH (rLH) to FSH treatment may promote the dominance of a leading follicle when administered in the late follicular phase. The objective of this study was to find the optimal dose of rLH that can maintain the growth of a dominant follicle, whilst causing atresia of secondary follicles. METHODS Women w...

The processes that precisely control the selection of ovulatory follicles from a growing cohort are poorly understood. This reduction in follicle number occurs through several phases of selection, consequently we limit the use of the term 'selection' to the first major reduction of growing follicles, at the pre- to early antral stage. The final process of selection, achieving the appropriate ov...

In cattle, follicle dimension has been used as the main criterion for selection of oocytes for in vitro embryo production. However, follicles with similar diameters may be in very different physiologic phases. The aim of this study was to investigate whether morphology and developmental competence of cumulus-oocyte complexes (COCs) are related to the phase of development of the follicle, and pr...

Ovarian stimulation is usually carried out with exogenous gonadotropins to induce multiple follicle development and to mature more oocytes for in vitro Fertilization (IVF) [1]. According to the traditional folliculogenesis, antral follicles in each ovary are recruited from the late luteal phase of the preceding menstrual cycle for the following follicle phase. The dominant follicle is selected ...

Objectives of this study were to determine if concentrations of steroids, insulin-like growth factor-I (IGF-I) and IGF-II in follicular fluid, and numbers of LH and IGF-I receptors change during growth of the dominant follicle. Ovarian follicular development was monitored daily via ultrasound in lactating Holstein cows. Animals were bilaterally ovariectomized when the dominant follicle (DF) was...

There is large variation in dominant follicle diameter at the time of GnRH-induced ovulation in the CO-Synch protocol [a first GnRH injection on d -9 (GnRH1), followed by PGF(2alpha) on d -2, and a second GnRH injection (GnRH2) with timed AI on d 0], and the reason for the presence of small dominant follicles at GnRH2 is not known. Our hypothesis was that ovulatory response to GnRH1 and progest...

intrauterine insemination (iui) has been widely used for the treatment of infertility. several prognostic factors for iui outcome have been proposed, including the endometrial thickness and follicle numbers, etiology and duration of infertility and morphology, type and motility of sperms. a total of 463 iui cycles in which clomiphene citrate and/or human menopausal gonadotrophin (hmg) were used...