Efficacy of modified natural cycle vs. hormone replacement therapy in oocyte donation for recipients of advanced maternal age: a retrospective study.

Purpose: To compare the efficacy of modified natural cycle (mNC) preparation versus hormone replacement therapy (HRT) for endometrial preparation in recipients of donated oocytes, specifically focusing on pregnancy rates in women of advanced maternal age.

Methods: Retrospective multicenter analysis conducted between 2021 and 2024. It includes 220 cycles of fresh single blastocyst transfers resulting from oocyte donation.

Enhancing predictive models for egg donation: time to blastocyst hatching and machine learning insights.

Background: Data sciences and artificial intelligence are becoming encouraging tools in assisted reproduction, favored by time-lapse technology incubators. Our objective is to analyze, compare and identify the most predictive machine learning algorithm developed using a known implantation database of embryos transferred in our egg donation program, including morphokinetic and morphological variables, and recognize the most predictive embryo parameters in order to enhance IVF treatments clinical outcomes.

Methods: Multicenter retrospective cohort study carried out in 378 egg donor recipients who performed a fresh single embryo transfer during 2021.

Factors affecting biochemical pregnancy loss (BPL) in preimplantation genetic testing for aneuploidy (PGT-A) cycles: machine learning-assisted identification.

Purpose: To determine the factors influencing the likelihood of biochemical pregnancy loss (BPL) after transfer of a euploid embryo from preimplantation genetic testing for aneuploidy (PGT-A) cycles.

Methods: The study employed an observational, retrospective cohort design, encompassing 6020 embryos from 2879 PGT-A cycles conducted between February 2013 and September 2021. Trophectoderm biopsies in day 5 (D5) or day 6 (D6) blastocysts were analyzed by next generation sequencing (NGS).

Exploring uterine contractility frequency in infertile population: A comparative study among different control groups with and without a C-section defect.

Objective: Women undergoing IVF who have had a previous c-section (CS) have a lower live birth rate than those with a previous vaginal delivery. However, the precise underlying mechanisms need clarification. Does a previous CS affect the pattern of uterine contractility?.

Continuous ovarian stimulation: a proof-of-concept study exploring the uninterrupted use of corifollitropin α in DuoStim cycles for enhanced efficiency and patient convenience (Alicante protocol).

Objective: To explore the use of weekly continuous dosing of corifollitropin α in DuoStim cycles.

Design: Pilot-matched case-control study.

Setting: Private fertility center.

The impact of (very) young donor age on euploid rates: An analysis of 1831 trophectoderm biopsies evaluated with 24-chromosome NGS screening in oocyte donation cycles.

Research Question: Conflicting data exists regarding whether a younger age of donors has a negative influence on the outcomes of oocyte donation cycles. Is there any correlation between a younger age of donors and the rate of embryonic aneuploidy in oocyte donation cycles?

Design: Retrospective study including 515 oocyte donation cycles carried out between February 2017 and November 2022. Comprehensive chromosomal screening was performed on 1831 blastocysts.

Micronized natural progesterone (Seidigestan) vs GnRH antagonists for preventing the LH surge during controlled ovarian stimulation (PRO_NAT study): study protocol of a randomized clinical trial.

Introduction: Progesterone-primed cycles effectively suppress the pituitary LH surge during ovarian stimulation in oocyte donors and in the infertile population. Particularly in oocyte donors, the use of synthetic progesterone (progestins) has been explored in prospective clinical trials, showing mixed results. This trial was designed to determine whether the use of micronized natural progesterone is as effective as the GnRH-antagonist protocol in terms of the number of mature oocytes (MII) retrieved in oocyte donation cycles as a primary outcome, and it also aims to explore the corresponding results in recipients as a secondary outcome.

Impact of Group vs Individual Embryo Culture Strategies on Blastocyst and Clinical Outcomes.

Embryo culture is one of the most important steps in an assisted reproduction laboratory. Embryos can be cultured individually, one embryo per media drop, or in groups, culturing several embryos in the same media drop. Due to the controversy generated on this subject, we wondered which embryo culture method would have the best results in terms of quality and blastocyst formation rate.

Conventional follicular-phase ovarian stimulation vs. luteal-phase stimulation in suboptimal responders: a randomized controlled trial.

Objective: To compare the oocyte yield between follicular-phase stimulation (FPS) and luteal-phase stimulation (LPS) in suboptimal responders.

Design: Prospective, randomized, crossover clinical trial.

Patients: Forty-one patients with infertility according to the POSEIDON (Patient-Oriented Strategies Encompassing IndividualizeD Oocyte Number) criteria (1b/2b).

Endometrial receptivity in women with endometriosis.

As endometriosis is recognized as a contributing factor to infertility, prompting couples to embark on Assisted Reproductive Technology (ART) treatments, it becomes crucial to comprehend the extent and way this condition can affect success rates. Natural conception data reveal lower success rates for women with endometriosis, yet the same cannot be extrapolated to the outcomes of in vitro fertilization (IVF). In recent years, advancements in the ART process, particularly the distinct stages of the IVF pathway and investigations into embryo quality have shown a comparable rate of embryonic quality and chromosomal normalcy (euploidy) between embryos obtained from individuals with or without endometriosis.

Synthesis of 2-aminopropyl benzopyran derivatives as potential agents against triple-negative breast cancer.

Synthesis of three series of 2-aminopropyl derivatives containing a benzopyran nucleus was performed to evaluate their performance against triple-negative breast cancer cell lines (MDA-MB-231 and MDA-MB-436) and normal breast epithelial cells (MCF10A). For the three series, the cytotoxic activity was as follows: -methylated derivatives (tertiary amines) 5b, 6b, and 7b > secondary amine benzopyrans 5, 6, and 7 > quaternary amine salts 5c, 6c, and 7c > free phenolic derivatives 5a, 6a, and 7a. The structure-activity relationship showed the importance of the presence of an amine group and a -fluorobenzyloxy substituent in the chromanol ring (IC values from 1.

Random-start ovarian stimulation in an oocyte donation programme: a large, single-centre, experience.

Research Question: Do live birth rates differ between recipients matched with donors using conventional ovarian stimulation compared with those using random-start protocols?

Design: Retrospective analysis of 891 ovarian stimulations in egg donors (January-December 2018) and clinical outcomes in matched recipients (n = 935). Donors commenced ovarian stimulation on day 1-3 of the menstrual cycle (n = 223) or in the mid/late-follicular (n = 388) or luteal phase (n = 280) under a conventional antagonist protocol. Live birth rate of matched recipients was the main outcome.

Luteal phase stimulation in double ovarian stimulation cycles is not affected by the follicle-stimulating hormone (FSH) receptor genotype: double ovarian stimulation is beneficial independently of the genotype at position 680 of the follicle-stimulating hormone receptor.

Objectives: To determine whether follicle-stimulating hormone receptor (FSHR) genotype influences the outcome of ovarian stimulation treatment in luteal phase.

Methods: A total of 299 patients were included in a retrospective study between July 2017 and December 2021. These patients carried out a double stimulation protocol and the variant Asn680Ser (rs6166; c.

Progesterone levels on the day of embryo transfer using a single pessary of 400mg of vaginal progesterone vs. 200mg x2 pessaries in hormonal replacement cycles.

Objective: Does the use of 400mg pessaries of micronized progesterone provide comparable results as pessaries of 200mg x2, in terms of progesterone levels in hormonal replacement cycles for embryo transfer?.

Methods: Retrospective cohort study based on 299 embryo transfer treatments under artificial endometrial preparation carried out at Instituto Bernabeu. 131 patients received 1 pessary of 400 mg b.

Factors associated with embryo mosaicism: a systematic review and meta-analysis.

Purpose: Evaluate which factors are involved in the increased rate of mosaicism in embryos.

Methods: A systematic review and meta-analysis was performed. After an exhaustive search of the literature, a total of seven papers were included in the analysis.

Influence of the starting day of luteal phase stimulation on double stimulation cycles.

Background: Double ovarian stimulation is one of the most used strategies in poor-prognosis patients. There is a high heterogeneity between the studies regarding the execution of this stimulation protocol. The aim of this study was to investigate whether the day on which luteal phase stimulation begins after the first oocyte retrieval affects ovarian response in DuoStim cycles.

Identification of novel candidate genes associated with meiotic aneuploidy in human embryos by whole-exome sequencing.

Purpose: To identify novel genetic variants responsible for meiotic embryonic aneuploidy.

Methods: A prospective observational cohort study that included 29 couples who underwent trophectoderm biopsies from 127 embryos and performed whole-exome sequencing (WES) between November 2019 and March 2022. Patients were divided into two groups according to the expected embryo aneuploidy rate based on maternal age.

Noninvasive preimplantation genetic testing using the embryo spent culture medium: an update.

Purpose Of Review: The presence of cell-free DNA (cf-DNA) in the embryo spent culture medium allows to develop a noninvasive PGT-A (niPGTA). Noninvasive PGT-A may provide a simpler, safer and less costly approach to preimplantation genetic testing of aneuploidy (PGT-A). Furthermore, niPGTA would provide wider access to embryo genetic analysis and circumvent many legal and ethical considerations.

Sexually Dimorphic Adolescent Trajectories of Prefrontal Endocannabinoid Synaptic Plasticity Equalize in Adulthood, Reflected by Endocannabinoid System Gene Expression.

How sex influences prefrontal cortexes (PFCs) synaptic development through adolescence remains unclear. In this study we describe sex-specific cellular and synaptic trajectories in the rat PFC from adolescence to adulthood. The excitability of PFC layer 5 pyramidal neurons was lower in adult females compared with other developmental stages.

Characterization of the Endometrial Microbiome in Patients with Recurrent Implantation Failure.

An abnormal endometrial microbiota has been associated with implantation failure; therefore, it may be important to evaluate it in order to improve reproductive outcomes in infertile patients. The main objective of our study was to compare the endometrial microbiome of patients with recurrent implantation failure (RIF) and control patients undergoing assisted reproduction treatment (ART). A prospective cohort study including forty-five patients with their own or donated gametes.

Buried and surface oil degradation - Evaluating bioremediation to increase PAHs removal through linear mathematical models.

A bioremediation approach with tide simulation for buried and surface oil degradation was tested for removal of two, three and four rings polycyclic aromatic hydrocarbons (PAHs). Linear models depicted degradation constants of individual PAH as simple additive function of their initial concentrations (C) in contaminated sand, hydrophobicity, sampling layer and treatment conditions. For all PAHs and treatment conditions, the degradation of oil in buried layers was faster than at the surface.

Does mRNA COVID-19 vaccination in oocyte donors impact ovarian stimulation parameters or IVF outcomes for recipients?

Research Question: What is the effect of mRNA severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccination in young oocyte donors in terms of ovarian response to stimulation, fertilization rate, embryo development and clinical outcomes in recipients?

Design: This retrospective, multicentre cohort study evaluated 115 oocyte donors who had undergone at least two ovarian stimulation protocols (before and after complete SARS-CoV-2 vaccination) between November 2021 and February 2022. Comparisons were made of the primary outcomes of days of stimulation, total dose of gonadotrophins and laboratory performance in ovarian stimulation in oocyte donors before and after vaccination. A total of 136 cycles in matched recipients were analysed as secondary outcomes and, from those, 110 women received a fresh single-embryo transfer, with analysis of biochemical β-human chorionic gonadotrophin concentrations and rates of clinical pregnancy with heartbeat.

Exploring self-detection of the endogenous LH surge using a urine test as a tool to predict a suboptimal response to gonadotropin-releasing hormone agonist trigger during in vitro fertilization cycles.

Objective: Is self-detection of the endogenous LH surge using a urine testing a reliable method to confirm a successful gonadotropin-releasing hormone agonist (GnRHa) trigger in IVF cycles?

Methods: Prospective observational study including a total of 103 oocyte donation cycles between November 2019 and January 2020. Urine LH testing (Akralab SL, Spain, cut-of value 30 mIU/mL) was performed at home in samples from the first micturition in the morning after the GnRHa trigger and a picture of the result was sent to the nurse coordinator; this information was concealed and only disclosed after oocyte aspiration.

Results: From the total group, two cycles were excluded.

IL-6/IL-10 and IL-1β/IL-4 ratios associated with poor ovarian response in women undergoing in-vitro fertilization.

The aim of this work was to evaluate whether serum cytokines levels are associated with ovarian response in IVF. 149 patients were included in a retrospective study. Cytokines IL-2, IL-4, IL- 6, IL-8, IL-10, VEGF, IFNγ, TNFα, IL-1α, IL-1β, MCP-1 and EGF were measured by sandwich immunoassay previously to ovarian stimulation.