ABSTRACTObjectiveTo analyze oocyte competence in gonadotropin‐releasing hormone agonist (GnRHa) stimulation cycles with regard to maturity, fertilization and blastocyst rate, as well as clinical outcome (pregnancy and live‐birth rate), in relation to follicular volume, measured by three‐dimensional transvaginal sonography (3D‐TVS), and follicular fluid composition.MethodsThis was a prospective single‐center study conducted between June 2012 and June 2014, including 118 ovum pick‐ups with subsequent embryo transfer. Ovarian stimulation was performed using the GnRHa long protocol. Of 1493 follicles aspirated individually, follicular volume was evaluated successfully in 1236 using automated 3D‐TVS during oocyte retrieval. Oocyte maturity and blastocyst development were tracked according to follicular volume. Intrafollicular concentrations of estradiol, testosterone, progesterone, luteinizing hormone, follicle‐stimulating hormone and granulocyte–colony stimulating factor were quantified by immunoassay. Clinical outcome, in terms of implantation rate, (clinical) pregnancy rate, miscarriage and live‐birth rate (LBR), was evaluated.ResultsFollicles were categorized, according to their volume, into three arbitrary groups, which included 196 small (8–12 mm/0.3–0.9 mL), 772 medium (13–23 mm/1–6 mL) and 268 large (≥ 24 mm/> 6 mL) follicles. Although oocyte recovery rate was significantly lower in small follicles compared with medium and large ones (63.8% vs 76.6% and 81.3%, respectively; P < 0.001), similar fertilization rates (85.1% vs 75.3% and 81.4%, respectively) and blastocyst rates (40.5% vs 40.6% and 37.2%, respectively) per mature metaphase II oocyte were observed. A trend towards higher LBR after transfer of blastocysts derived from small (< 1 mL) follicles compared with medium (1–6 mL) or large (> 6 mL) follicles (54.5% vs 42.0%, and 41.7%, respectively) was observed. No predictive value of follicular fluid biomarkers was identified.ConclusionsOur data indicate that the optimal follicular volume for a high yield of good quality blastocysts with good potential to lead to a live birth is 13–23 mm/1–6 mL. However, oocytes derived from small follicles (8–12 mm/0.3–0.9 mL) still have the capacity for normal development and subsequent delivery of healthy children, suggesting that aspiration of these follicles should be encouraged as this would increase the total number of blastocysts retrieved per stimulation. Copyright © 2017 ISUOG. Published by John Wiley & Sons Ltd.

Vitrification with the use of "Open" carrier devices (Cryoloop, cryotop, cryoleaf. Vitriplug) which allowed the contact with liquid nitrogen has become a more popular way to achieve cooling rate superior to 20.000 degrees C/min. Even though the question of contamination with liquid nitrogen during ultra-rapid cooling and storage remain debatable with the use of "open" devices, it is important to revise the carrier system in a way, which minimizes the risk of contamination. According to the EU tissues and cells directive, it is advisable that the cooling and storage should be carried out in embryo carrier devices ensuring complete separation of the embryos from liquid nitrogen in a way, which minimizes the risk of contamination. The consequence of a reduction in the cooling rate resulting from the heat-insulating barrier of aseptic devices has to be counteracted by gradually increasing intracellular concentrations of cryoprotectants without inducing a toxic effect. We developed an aseptic vitrification method of vitrification for MII oocytes and embryos at different stage of development using the "VitriSafe" as "closed" carrier device. (C) 2010 Elsevier Masson SAS. All rights reserved.

The use of high levels of cryoprotectants (CPs) in solutions applied to vitrify oocytes or embryos is an argument to still prefer slow freezing procedure. Is it a justified argument? Out of three studies using mice zygotes we may assume that (i) the intracellular concentration of CPs is far lower than the one in the vitrification solutions, (ii) the intracellular concentration of CPs in the vitrified zygote is in contrary to the common beliefs even lower than the one observed after a slow freezing procedure, (iii) survival after slow freezing reflects the presence of an intracellular vitrified state in these cells.

ADAMTS (a disintegrin and metalloproteinase domain with thrombospondin motifs) constitute a family of endopeptidases related to matrix metalloproteinases. These proteases have been largely implicated in tissue remodeling and angiogenesis associated with physiological and pathological processes. To elucidate the in vivo functions of ADAMTS-12, we have generated a knockout mouse strain (Adamts12−/−) in which Adamts12 gene was deleted. The mutant mice had normal gestations and no apparent defects in growth, life span and fertility. By applying three different in vivo models of angiogenesis (malignant keratinocyte transplantation, Matrigel plug and aortic ring assays) to Adamts12−/− mice, we provide evidence for a protective effect of this host enzyme toward angiogenesis and cancer progression. In the absence of Adamts-12, both the angiogenic response and tumor invasion into host tissue were increased. Complementing results were obtained by using medium conditioned by cells overexpressing human ADAMTS-12, which inhibited vessel outgrowth in the aortic ring assay. This angioinhibitory effect of ADAMTS-12 was independent of its enzymatic activity as a mutated inactive form of the enzyme was similarly efficient in inhibiting endothelial cell sprouting in the aortic ring assay than the wild-type form. Altogether, our results show that ADAMTS-12 displays antiangiogenic properties and protect the host toward tumor progression.

During embryo vitrification, it is advisable that cooling and storage should occur in a carrier device in which there is complete separation of the embryos from liquid nitrogen to ensure asepsis. The consequence of a reduction in the cooling rate resulting from the heat-insulating barrier aseptic devices has to be counteracted by gradually increasing intracellular concentrations of cryoprotectants without inducing a toxic effect. Blastocysts originating from couples with male and/or female factor infertility (group 1) or from oocyte donors (group 2) or from in-vitro matured oocytes (group 3) were gradually exposed to increasing concentrations of dimethylsulphoxide/ethylene glycol (5/5%, 10/10% and 20/20%) before aseptic vitrification using a specially designed carrier (VitriSafe), a modification of the open hemi-straw plug device. A total of 120 aseptic vitrification/warming cycles were performed in group 1, 91 in group 2 and 22 in group 3. Survival rates before embryo transfer, ongoing pregnancy and implantation rates were as follows: for group 1, 73, 43 and 26%; for group 2, 88, 53 and 34%; and for group 3, 69, 50 and 38%, respectively. In spite of reduced cooling rates due to aseptic vitrification conditions, a three-step exposure to cryoprotectant solutions protects the embryos effectively from cryo-injuries and guaranties high survival rates.

La vitrification est un processus par lequel un liquide se solidifie sans formation de cristaux. Cette technique de cryopréservation consiste à exposer pour de courtes durées les embryons à des concentrations élevées en cryoprotecteurs puis de les refroidir ultrarapidement, ce qui induit une augmentation de la viscosité favorisant la formation d'un état vitreux intra- et extracellulaire. Malgré l'obtention de taux de survie et de grossesse respectivement de l'ordre de 80 et 30 % accompagnés de la naissance d'enfants en parfaite santé, après vitrification de zygotes, d'embryons segmentés, de morulae et de blastocystes, une appréhension subsiste quant à son application dans les centres d'Assistance médicale à la procréation. L'utilisation de concentration élevée de cryoprotecteurs et de technique de refroidissement et de stockage des embryons dans des conditions non stériles sont des arguments qui discréditent la technique. Le but de cet article est de répondre dans la première partie à différentes questions concernant la technique et les appréhensions qu'elle suscite. Dans une deuxième partie seront présentés les résultats de la vitrification des embryons, et analysées les raisons liées à la difficulté de cryopréserver les blastocystes.

Vitrification is a cryopreservation strategy where cells are converted into a glass-like amorphous solid which is free of any crystalline structure. Such process is achieved by a combination of high concentration of cryoprotectant and an extremely high cooling rate. In the last years, survival rates of up to 80% after thawing and pregnancy rates of almost 30% could be achieved after transfer of vitrified embryos at the zygote, cleavage, morula and blastocyst stages. Also deliveries of healthy babies have been reported numerous times. To this day, a limited interest in this technique can be noted. The explanation may lye in the apprehension of many ART units regarding exposure of embryos to high concentrations of cryoprotectants and storage in non sterile conditions. The aim of the first part of this article, is to analyse if such fears are justified on the basis that vitrification mimics conditions already in use for many years in slow-cooling procedures where cells are plunged into liquid nitrogen at around -30 degrees C and secondly since storage of embryos are now possible in high aseptic conditions. In the second part, results on survival after thawing, pregnancy rates and baby take home rates of vitrified embryos will be presented and the problems associated with vitrification of blastocysts will be discussed.

The technology of reproduction progressed considerably during the last decade, leading to a certain availability of in vitro methods for fertilisation, oocyte maturation and embryo culture. The most spectacular manipulations are cloning and transgenesis. This review focuses on the early appearance of germinal cell precursors and the long-standing fate of gametes in mammals. The evident complexity and long-term programming of events in gametes and early embryos explain part of the difficulties encountered during the development of in vitro and in vivo methods such as multiple Ovulation and embryo transfer (MOET), oestrus synchronisation, ovulation induction, superovulation, in vitro maturation and fertilisation, cryopreservation, transgenesis, nuclear transfer and cloning) and the occurrence of unexpected alterations of development, e.g. embryonic or fetal mortality, large-weight newborn syndrome and other dysregulations ill imprinting or DNA transmission.

Caesarian section is amongst the most commonly performed surgical interventions in Veterinary practice in Belgium today. The main indication for caesarian section in the bovine species is foetal oversize. The goals of this paper are to review the topographical anatomy of the abdomen in the pregnant and non-pregnant cow, and the various caesarean techniques available at this time. The choice of a specific surgical method depends on three main factors: the environment in which the practitioner must operate, the condition of the cow, and that of the foetus (vitality, size, position). Also presented in this paper is a description of the suture materials and needles available, and the various methods of suture used for the uterus and abdominal waif. The advantages and disadvantages of each method are reviewed as are the main substances used for premedication (tranquillisers, uterine relaxants, anaesthetics), and for postmedication (oxytocin, prostaglandins, corticosteroids, antibiotics). The potential complications associated with the caesarean section are considered.