Search results for "Embryo implantation"
showing 10 items of 92 documents
Use of cryo-banked oocytes in an ovum donation programme: a prospective, randomized, controlled, clinical trial
2010
background: An efficient oocyte cryopreservation method is mandatory to establish a successful egg-banking programme. Although there are increasing reports showing good clinical outcomes after oocyte cryopreservation, there is still a lack of large controlled studies evaluating the effectiveness of oocyte cryo-banking. In this study, we aimed to compare the outcome of vitrified-banked oocytes with the gold standard procedure of employing fresh oocytes. methods: A randomized, prospective, triple-blind, single-centre, parallel-group controlled-clinical trial (NCT00785993), including 600 recipients (a ¼ 0.05 and power of 80% for sample-size calculation) selected among 1032 eligible patients fr…
Assessment of the implantation of day-2 human embryos by morphometric nonsubjective parameters
2014
Objective: To demonstrate the usefulness of image analysis in designing objective embryonic morphometric variables. Design: Retrospective study of 214 top-quality day-2 embryo photographs from 50 double-embryo transfers resulting in no pregnancy (group 0) and 57 resulting in twin pregnancy (group 1). Setting: Human reproduction unit. Patient(s): Study of 107 in vitro fertilization intracytoplasmic sperm injection (IVF ICSI) cycles in women age<36 years with doubleembryo transfer of top-quality embryos. Only the first cycle of IVF ICSI was included. Intervention(s): Standard IVF ICSI protocols. Main Outcome Measure(s): The embryo photographs were analyzed using the ImageJ program. The effect…
Assessment of endometrial volume by three-dimensional ultrasound prior to embryo transfer: clues to endometrial receptivity
1999
The aim of the present prospective study was to obtain quantitative data on endometrial volume by three-dimensional (3D) ultrasound at the time of embryo transfer in an in-vitro fertilization programme and to assess its value in predicting endometrial receptivity. The cycles (n = 72) were classified according to endometrial volume: group A2 ml, group B 2-4 ml, and group C4 ml. Comparisons of the groups showed that pregnancy and implantation rates were significantly lower (P0.05) in the group of patients with an endometrial volume2 ml. Furthermore, no pregnancy was achieved with an endometrial volume1 ml. It is concluded that endometrial volume by 3D transvaginal ultrasound may become a new …
Limited implantation success of direct-cleaved human zygotes: a time-lapse study.
2012
Objective To evaluate embryos with direct cleavage (≤5 hours) from two to three cells (DC2–3) and correlate this morphokinetic parameter to implantation and ongoing pregnancy. Design Clinical multicenter retrospective study. Setting Private in vitro fertilization (IVF) centers. Patient(s) From three clinics, a total of 979 treatments including 5,225 embryos using autologous or donated oocytes, of which 1,659 embryos were transferred. Intervention(s) None. Main Outcome Measure(s) Clinical pregnancy confirmed by ultrasound in week 7. Result(s) Of the total embryo cohort, 715 (13.7%) underwent direct cleavage from two to three cells, 1,659 embryos were transferred to recipients, and 109 of the…
Collapse of blastocysts is strongly related to lower implantation success: a time-lapse study.
2015
Study question Is there an association between blastocyst collapse patterns and implantation potential? Summary answer Embryos that exhibit collapse are as likely to hatch as those that do not, but are less likely to implant and should not be replaced if alternatives are available. What is known already Studies of blastocyst collapse in different species of mammals have found that most blastocysts, that experience consecutive weak contractions, hatch successfully whereas those that exhibit strong contractions or collapse, fail to hatch. Study design, size, duration Retrospective cohort study. Seven hundred and fifteen transferred blastocysts were analyzed from July 2012 to May 2013. Partici…
Genetic polymorphisms of serotonin transporter and receptor 1A could influence success during embryo implantation and maintenance of pregnancy
2012
Objective To explore whether serotonin-related gene polymorphisms influence clinical outcomes of IVF treatment in recipients using donated oocytes. Design Nested case-control study. Setting University-affiliated infertility clinic. Patient(s) Two hundred forty-five women undergoing IVF treatment with donated oocytes. Intervention(s) None. Main Outcome Measure(s) Genotype and haplotype analysis of the serotonin transporter-linked polymorphic region (5-HTTLPR), rs1800532, rs6295, rs6313, and rs3813929, between recipients grouped according to the results of the oocyte donation for IVF treatment. Result(s) No differences were found between genotype distribution of the tryptophan hydroxylase 1, …
Inhibition of Histone Deacetylase Activity in Human Endometrial Stromal Cells Promotes Extracellular Matrix Remodelling and Limits Embryo Invasion
2011
Invasion of the trophoblast into the maternal decidua is regulated by both the trophoectoderm and the endometrial stroma, and entails the action of tissue remodeling enzymes. Trophoblast invasion requires the action of metalloproteinases (MMPs) to degrade extracellular matrix (ECM) proteins and in turn, decidual cells express tissue inhibitors of MMPs (TIMPs). The balance between these promoting and restraining factors is a key event for the successful outcome of pregnancy. Gene expression is post-transcriptionally regulated by histone deacetylases (HDACs) that unpacks condensed chromatin activating gene expression. In this study we analyze the effect of histone acetylation on the expressio…
Reproductive Biology Including Evidence for Superfetation in the European Badger Meles meles (Carnivora: Mustelidae)
2015
The reproductive biology of the European badger (Meles meles) is of wide interest because it is one of the few mammal species that show delayed implantation and one of only five which are suggested to show superfetation as a reproductive strategy. This study aimed to describe the reproductive biology of female Irish badgers with a view to increasing our understanding of the process of delayed implantation and superfetation. We carried out a detailed histological examination of the reproductive tract of 264 female badgers taken from sites across 20 of the 26 counties in the Republic of Ireland. The key results show evidence of multiple blastocysts at different stages of development present s…
Cleavage of endometrial α-integrins into their functional forms is mediated by proprotein convertase 5/6.
2012
Background Proprotein convertases (PCs) post-translationally activate a large number of protein precursors through limited cleavage. PC5/6 (PC6) in the human endometrium is tightly regulated during receptivity for embryo implantation. Integrins are transmembrane glycoproteins, some of which play an important role in the adhesive interactions between the trophoblast (blastocyst) and uterine epithelium at implantation. Integrins require PC cleavage for post-translational modification. We hypothesize that pro-integrin-αs in the endometrial epithelium are post-translationally cleaved by PC6 into functional subunits for the binding of blastocyst and adhesion of extracellular matrix proteins. Met…
Is the nuclear status of an embryo an independent factor to predict its ability to develop to term?
2012
Objective To determine the prognostic impact of the embryo nuclear status at day 2 among other major morphologic parameters (first cleavage at day 1, number of blastomeres and anuclear fragmentation at day 2) on the birth rate. Design Retrospective study. Setting Hospital IVF department. Patient(s) Women undergoing 1,629 day 2 transfers of 2,732 embryos from May 2006 to November 2008. Intervention(s) Four groups according to the embryo nuclear status. Main Outcome Measure(s) Implantation, miscarriage, and birth rates. Result(s) Univariate analysis indicated significantly higher birth rates when all blastomeres were mononucleated (15.0%) compared with embryos with not all blastomeres mononuc…