Oocyte maturation arrest is a complex problem not clearly understood; only few cases showing a complete oocyte maturation failure has been reported previously, still the exact incidence remains unknown. Failure to resume meiosis (a specialized type of cell division that reduces the chromosome number by half) in vivo may arise at one of the following three levels: absent or incomplete luteinizin...

Oocyte maturation arrest is a complex problem not clearly understood; only few cases showing a complete oocyte maturation failure has been reported previously, still the exact incidence remains unknown. Failure to resume meiosis (a specialized type of cell division that reduces the chromosome number by half) in vivo may arise at one of the following three levels: absent or incomplete luteinizin...

Mammalian mitochondrial DNA (mtDNA) is a small, maternally inherited genome that codes for 13 essential proteins in the respiratory chain. Mature oocytes contain more than 150 000 copies of mtDNA, at least an order of magnitude greater than the number in most somatic cells, but sperm contain only approximately 100 copies. Mitochondrial oxidative phosphorylation has been suggested to be an impor...

Background: Diabetes mellitus is a metabolic condition characterized by elevated blood glucose levels secondary to absolute impairment of insulin secretion. Maternal diabetes has been demonstrated to adversely affect pre implantation embryo development and pregnancy outcomes. Emerging evidence has implicated that these effects are associated with compromised oocyte competence. Several developme...

Background During a normal menstrual cycle, progesterone prepares the endometrium for pregnancy by stimulating proliferation in response to human chorionic Gnadotropin produced by the corpus luteum. Many questions were raised about the role of follicular fluid aspiration on the granuloma cells at the time of oocyte retrieving during the ART cycles. Authors believes that oocyte retrieval might d...

BACKGROUND The growth pattern of the smallest ovarian follicles in humans is still incompletely documented. Using follicle hemispheres in thick histological sections, morphometric changes of primordial to primary follicles and possible age-related effects were evaluated. METHODS In ovarian sections from 25 females aged 4-39 years a total of 1122 primordial, transitory or primary follicles wer...

Over the last several decades, a number of therapies have been developed that manipulate ovarian follicle growth to improve oocyte quality and conception rates in cattle. Various strategies have been proposed to improve the responses to reproductive biotechnologies following timed artificial insemination (TAI), superovulation (SOV) or ovum pickup (OPU) programmes. During TAI protocols, final fo...

OBJECTIVE To investigate the oocyte quality in patients with severe ovarian hyperstimulation syndrome (OHSS). DESIGN Self-controlled clinical study. SETTING University teaching hospital. PATIENT(S) Twenty-two patients from our assisted reproductive technology (ART) program who developed severe OHSS during their first controlled ovarian hyperstimulation for IVF or intracytoplasmic sperm in...

Developing a culture system for preantral follicles has important biotechnological implications due to the potential to produce a large number of oocytes for embryo production and transfer. To accomplish this goal, the present study was aimed to culture preantral follicles in the presence of different media, sera and FSH concentrations. Six-week-old preantral follicles (95 ± 5 µm) were cultured...