Initiation and maintenance of the pluripotent epiblast in pre-implantation human development is independent of NODAL signaling.

The human blastocyst contains the pluripotent epiblast from which human embryonic stem cells (hESCs) can be derived. ACTIVIN/NODAL signaling maintains expression of the transcription factor NANOG and in vitro propagation of hESCs. It is unknown whether this reflects a functional requirement for epiblast development in human embryos.

Transcription factor-based transdifferentiation of human embryonic to trophoblast stem cells.

During the first week of development, human embryos form a blastocyst composed of an inner cell mass and trophectoderm (TE) cells, the latter of which are progenitors of placental trophoblast. Here, we investigated the expression of transcripts in the human TE from early to late blastocyst stages. We identified enrichment of the transcription factors GATA2, GATA3, TFAP2C and KLF5 and characterised their protein expression dynamics across TE development.

Impact of double trophectoderm biopsy on reproductive outcomes following single euploid blastocyst transfer.

Objectives: To study the effect of double trophectoderm biopsy on clinical outcomes following single euploid blastocyst transfer.

Study Design: Retrospective cohort study of 2046 single euploid frozen-thawed blastocyst transfers from January 2015 to June 2022 in a single centre. All patients undergoing a frozen-thawed embryo transfer (FTET) cycle with euploid blastocysts, biopsied for any indication, were included.

Integrating imaging-based classification and transcriptomics for quality assessment of human oocytes according to their reproductive efficiency.

Purpose: Utilising non-invasive imaging parameters to assess human oocyte fertilisation, development and implantation; and their influence on transcriptomic profiles.

Methods: A ranking tool was designed using imaging data from 957 metaphase II stage oocytes retrieved from 102 patients undergoing ART. Hoffman modulation contrast microscopy was conducted with an Olympus IX53 microscope.

Live birth rate following a euploid blastocyst transfer is not affected by double vitrification and warming at cleavage or blastocyst stage.

Purpose: To compare reproductive outcomes following a euploid embryo transfer, between those embryos vitrified-warmed twice to those vitrified-warmed once.

Methods: We retrospectively analysed 694 single euploid frozen embryo transfer cycles following preimplantation genetic testing for aneuploidy (PGT-A). For cycles in group 1 (N = 451), embryos were biopsied for PGT-A at blastocyst stage and vitrified.

Next Generation Sequencing Detects Premeiotic Errors in Human Oocytes.

Autosomal aneuploidy is the leading cause of embryonic and foetal death in humans. This arises mainly from errors in meiosis I or II of oogenesis. A largely ignored source of error stems from germinal mosaicism, which leads to premeiotic aneuploidy.

Effectiveness of modified downregulation for women with moderate and severe adenomyosis of the uterus prior to frozen thawed embryo transfer (MODA) study protocol: a pragmatic randomised-controlled trial.

Introduction: Adenomyosis can adversely reduce chances of pregnancy in couples undergoing assisted conception. We aim to evaluate the effect of two different downregulation protocols on the reproductive outcomes in women with moderate and severe adenomyosis undergoing frozen-thawed embryo transfer (FTET).

Methods And Analysis: We will conduct a two-armed pragmatic randomised clinical trial comparing modified downregulation with gonadotrophin-releasing hormone (GnRH) analogue for 6 weeks to standard downregulation with GnRH analogue for 1 week prior to FTET.

Paternal age over 50 years decreases assisted reproductive technology (ART) success: A single UK center retrospective analysis.

Introduction: To study whether paternal age exerts an effect, independent of maternal age, on the outcomes of fresh in vitro fertilization/ intracytoplasmic sperm injection (IVF/ICSI) cycles. Semen quality deteriorates with increasing paternal age; however, there is conflicting evidence for any impact paternal age may have on the outcome of IVF/ICSI. Several retrospective and prospective cohort studies have shown that paternal age increases the miscarriage rate and reduces the live birth rate.

Preimplantation Genetic Testing for Aneuploidy: Current Perspectives.

Despite improvements in assisted reproduction techniques (ARTs), live birth rates remain suboptimal, particularly in women with advanced maternal age (AMA). The leading cause of poor reproductive outcomes demonstrated in women with AMA, as well as women with recurrent miscarriage and repetitive implantation failure, is thought to be due to high rates of embryonic aneuploidy. Preimplantation genetic testing for aneuploidies (PGT-A) aims to select an euploid embryo for transfer and therefore improve ART outcomes.

Chromosomal Analysis of Cumulus Cells as a Future Predictor for Oocyte Aneuploidy: A Case Report.

Background: Within the ovary, the optimal growth of the follicle, oocyte maturation and ovulation are highly conditioned by the two-way cross talk and interactions between the oocyte and the immediate somatic cells, known as cumulus cells (CCs). This biological communication between cell lines triggered the interest in the study of CCs as a biomarker of oocyte competence.

Case Presentation: The findings of a 45,X mosaic pattern on CCs from a female patient with unremarkable medical history are reported in this study.

Pre-implantation genetic testing for aneuploidy: motivations, concerns, and perceptions in a UK population.

Purpose: Pre-implantation genetic testing for aneuploidies (PGT-A) is a technique used as part of in vitro fertilisation to improve outcomes. Despite the upward trend in women utilising PGT-A, data on women's motivations and concerns toward using the technology, and perceptions having undergone the process, remain scarce.

Methods: This cross-sectional survey, based at a fertility clinic in the UK, utilised an electronic questionnaire to assess the motivations of women who undergo PGT-A and their perceptions and attitudes toward PGT-A after using it.

The First Livebirth Using Warmed Oocytes by a Semi-Automated Vitrification Procedure.

Background: The first successful livebirth using warmed oocytes (vitrified by the GAVI system) is reported in this paper. Embryologists throughout the world have vitrified oocytes using a manual technique which is susceptible to error and variation. In this era of automated laboratory procedures, vitrification was made semi-automatic by using the GAVI system.

Adding a low-quality blastocyst to a high-quality blastocyst for a double embryo transfer does not decrease pregnancy and live birth rate.

Introduction: The effect of embryo quality on clinical outcomes of assisted reproductive technology following a double transfer is not well defined, with some studies suggesting that a low-quality embryo transferred with a high-quality embryo decreases the live birth rate (LBR), compared with transferring a single high-quality embryo. Our study examined whether the quality of a second blastocyst transferred affects the outcome, controlling for the number of the available high-quality blastocysts (HQB).

Material And Methods: A historical cohort study of 2346 fresh blastocyst transfers in a single fertility clinic between 2013 and 2019.

Preconception tests at advanced maternal age.

Pregnancies at an advanced reproductive age are increasingly common. However, the safety of pregnancy remains a concern as maternal age is a recognized independent factor for various obstetric complications. Also, age is a risk factor for most systematic health problems and older women are more likely to enter into pregnancy with pre-existing conditions.

Oocyte yield in social, medical and donor oocyte cryopreservation cycles.

To determine if oocyte yield in women undergoing cryopreservation for social (SOC), medical (MOC) and oocyte donation (OD) cycles is comparable when matched for age. 315 oocyte retrievals were performed for SOC, 116 for MOC and 392 for OD. Non-parametric Kruskal-Wallis tests and Poisson regression were used to assess the impact of age stratification.

The Association Between Elevated Progesterone Level on Day of hCG Trigger and Live Birth Rates in ART Cycles: A Single Centre Observational Study.

Background: The advent of ovarian stimulation within an fertilization (IVF) cycle has resulted in modifying the physiology of stimulated cycles and has helped optimize pregnancy outcomes. In this regard, the importance of progesterone (P4) elevation at time of human chorionic gonadotrophin (hCG) administration within an IVF cycle has been studied over several decades. Our study aimed to evaluate the association of P4 levels at time of hCG trigger with live birth rate (LBR), clinical pregnancy rate (CPR) and miscarriage rate (MR) in fresh IVF or IVF-ICSI cycles.

Assisted conception in women of advanced maternal age.

A delay in childbearing to later in life has increased the number of women of advanced maternal age (AMA) opting for assisted reproduction. Women should be made aware that there are age-related changes to fertility, including a decline in oocyte reserve and quality, in addition to an increase in the number of oocyte chromosomal aberrations. Success rates of assisted reproductive technology (ART) cycles decrease with advanced maternal age.

The novel use of fertility quality of life (FertiQoL) treatment subscale to assess treatment acceptability in social egg freezing.

This is the first study to assess the impact of social egg freezing (SEF) on quality of life. This cross-sectional survey utilised the FertiQoL treatment module in women who underwent SEF between January 2008 and October 2019 (n = 94). The mean treatment score was 65.

Live birth rate is associated with oocyte yield and number of biopsied and suitable blastocysts to transfer in preimplantation genetic testing (PGT) cycles for monogenic disorders and chromosomal structural rearrangements.

Objectives: To investigate whether live birth (LB) is associated with oocyte yield and number of biopsied and suitable blastocyst to transfer following preimplantation genetic testing (PGT) for monogenic disorders (PGT-M) and chromosomal structural rearrangements (PGT-SR).

Study Design: All couples underwent controlled ovarian stimulation, blastocyst biopsy, vitrification and transfer of suitable embryo(s) in a frozen embryo transfer (FET) cycle.

Results: Of 175 couples who underwent PGT treatment, 249 oocytes retrievals were carried out and 230 FET were subsequently undertaken.

Perceptions, outcomes, and regret following social egg freezing in the UK; a cross-sectional survey.

Introduction: Social egg freezing enhances reproductive autonomy by empowering women with the capacity to delay their childbearing years, while preserving the opportunity to maintain biological relation with subsequent offspring. However, age-related obstetric complications, economic implications and the risk of unsuccessful future treatment make it a controversial option. Despite the upward trend in women electively cryopreserving their eggs, there is limited data about the women's perceptions, having undergone the process.