Meiotic maturation failure in primary ovarian insufficiency: insights from a bovine model.

Purpose: Oocytes from women presenting primary ovarian insufficiency (POI) generate viable embryos at a lower rate than non-POI women, but the mechanisms responsible for the lower oocyte quality remain elusive. Due to the scarcity of human oocytes for research, animal models provide a promising way forward. We aimed at investigating the molecular events characterizing final maturation in POI oocytes in a well-defined POI-like bovine model.

Single-cell proteomics reveals decreased abundance of proteostasis and meiosis proteins in advanced maternal age oocytes.

Advanced maternal age is associated with a decline in oocyte quality, which often leads to reproductive failure in humans. However, the mechanisms behind this age-related decline remain unclear. To gain insights into this phenomenon, we applied plexDIA, a multiplexed, single-cell mass spectrometry method, to analyze the proteome of oocytes from both young women and women of advanced maternal age.

Single-cell proteomics reveals decreased abundance of proteostasis and meiosis proteins in advanced maternal age oocytes.

Advanced maternal age is associated with a decline in oocyte quality, which often leads to reproductive failure in humans. However, the mechanisms behind this age-related decline remain unclear. To gain insights into this phenomenon, we applied plexDIA, a multiplexed data-independent acquisition, single-cell mass spectrometry method, to analyze the proteome of oocytes from both young women and women of advanced maternal age.

No association between LH levels and ovarian response in oocyte donors triggered with gonadotropin-releasing hormone agonist: A prospective study.

Objective: Are circulating luteinizing hormone (LH) levels predictive of ovarian response in oocyte donors triggered with gonadotropin-releasing hormone (GnRH) agonists?

Study Design: A prospective cohort study with 224 oocyte donation cycles between 2021 and 2022 at a single center, examined the relationship between circulating luteinizing hormone (LH) levels and ovarian response. Oocyte donors underwent GnRH antagonist downregulation followed by GnRH agonist trigger. LH, estradiol, and progesterone levels were measured on day one of stimulation, trigger-day and 12 h post-trigger.

Personalizing the first dose of FSH for IVF/ICSI patients through machine learning: a non-inferiority study protocol for a multi-center randomized controlled trial.

Background: Adequately selecting the initial follicle-stimulating hormone (FSH) dose during controlled ovarian stimulation (COS) is key for success in assisted reproduction. The objective of COS is to obtain an optimal number of oocytes to increase the chances of achieving a pregnancy, while avoiding complications for the patient. Current clinical protocols do achieve good results for the majority of patients, but further refinements in individualized FSH dosing may reduce the risk of poor ovarian response while also limiting the risk of ovarian hyperstimulation syndrome (OHSS) risk.

Moonshots and last miles: what it may take to treat infertility for all.

Innovation in medically assisted reproduction (MAR) is at an all-time high, with new technologies being developed for the laboratory and around the patient experience, and deployed quickly and effectively. Nevertheless, substantial improvements in the success of infertility care seem to elude the field. This article presents the view that MAR is missing the key innovation motor of mechanistic knowledge, which historically relates to a lack of public resources of the kind afforded to other diseases.

The expression levels of NOS2, HMOX1, and VEGFC in cumulus cells are markers of oocyte maturation and fertilization rate.

Throughout the reproductive life of women, cumulus cells (CC) protect the dormant oocyte from damage, act as sensors of the follicular microenvironment, and act as a gatekeeper for oocyte developmental potential. One such mechanism relies on the hypoxia-tolerance response, which, with age, decreases systematically, including in the ovary. We aimed to evaluate the association between gene expression related to hypoxia and aging in CC and reproductive results in in vitro fertilization cycles.

Long-term storage of vitrified oocytes does not affect pregnancy and live birth rates: analysis of 5362 oocyte donation cycles.

Research Question: Does long-term storage of vitrified oocytes affect laboratory and reproductive outcomes after intracytoplasmic sperm injection?

Design: Retrospective cohort study including 41,783 vitrified-warmed oocytes from 5362 oocyte donation cycles between 2013 and 2021. Five categories of storage time were established to analyse its effect on clinical and reproductive outcomes (≤1 year [reference group], 1-2 years, 2-3 years, 3-4 years and >4 years).

Results: The mean number of warmed oocytes was 8.

Specific processing of meiosis-related transcript is linked to final maturation in human oocytes.

Human meiosis in oocytes entails an intricate regulation of the transcriptome to support late oocyte growth and early embryo development, both crucial to reproductive success. Currently, little is known about the co- and post-transcriptional mRNA processing mechanisms regulating the last meiotic phases, which contribute to transcriptome complexity and influence translation rates. We analyzed gene expression changes, splicing and pre-mRNA processing in an RNA sequencing set of 40 human oocytes at different meiotic maturation stages, matured both in vivo and in vitro.

Significant differences in efficiency between two commonly used ionophore solutions for assisted oocyte activation (AOA): a prospective comparison of ionomycin and A23187.

Purpose: Despite the success of ICSI in treating severe male factor infertile patients, total fertilization failure (FF) still occurs in around 1-3% of ICSI cycles. To overcome FF, the use of calcium ionophores has been proposed to induce oocyte activation and restore fertilization rates. However, assisted oocyte activation (AOA) protocols and ionophores vary between laboratories, and the morphokinetic development underlying AOA remains understudied.

Exonic genetic variants associated with unexpected fertilization failure and zygotic arrest after ICSI: a systematic review.

Fertilization failure (FF) and zygotic arrest after ICSI have a huge effect on both patients and clinicians, but both problems are usually unexpected and cannot be properly diagnosed. Fortunately, in recent years, gene sequencing has allowed the identification of multiple genetic variants underlying failed ICSI outcomes, but the use of this approach is still far from routine in the fertility clinic. In this systematic review, the genetic variants associated with FF, abnormal fertilization and/or zygotic arrest after ICSI are compiled and analyzed.

No difference in morphokinetics between male and female preimplantation embryos from ART.

Research Question: Do morphokinetic parameters vary between male and female preimplantation embryos?

Design: This was a retrospective cohort study of 175 cycles between March 2018 and June 2021 at two reproductive centres. It included time-lapse data from 92 female and 83 male preimplantation embryos exclusively issued from fresh oocyte donation and undergoing intracytoplasmic sperm injection (ICSI). Only fresh elective single-embryo transfers on day 5 were assessed, and the sex of the embryo was confirmed at birth.

Sperm cryopreservation does not affect live birth rate in normozoospermic men: analysis of 7969 oocyte donation cycles.

Study Question: Does sperm cryopreservation influence the reproductive outcomes of normozoospermic patients in oocyte donation cycles?

Summary Answer: After controlling for confounders, the use of cryopreserved semen from normozoospermic patients does not affect pregnancy and live birth rates after elective ICSI.

What Is Known Already: Sperm cryopreservation by slow freezing is a common practice in ART. While frozen-thawed semen typically presents reduced motility and vitality, its use for ICSI is generally considered adequate in terms of reproductive outcomes.

Supporting first FSH dosage for ovarian stimulation with machine learning.

Research Question: Is it possible to identify accurately the optimal first dose of FSH in ovarian stimulation by means of a machine learning model?

Design: Observational study (2011-2021) including first IVF cycles with own oocytes. A total of 2713 patients from five private reproductive centres were included in the development phase (2011-2019) and 774 in the validation phase (2020-2021). Predictor variables included age, BMI, AMH, AFC and previous live births.

Tailored support may reduce mental and relational impact of infertility on infertile patients and partners.

Research Question: What is the psychological impact of infertility on infertile patients and partners of infertile patients?

Design: This online, international, quantitative survey assessed the impact of infertility on mental health, relationships and daily activities for 1944 respondents. Respondents were male or female infertile patients (n = 1037) or partners to infertile patients (n = 907; not necessarily partners of the patient sample) and were recruited at different stages of the treatment journey.

Results: The most common emotions were 'sadness' at infertility diagnosis and 'anxiety' during treatment.

How long can the sperm wait? Effect of incubation time on ICSI outcomes.

In sperm processing for IVF/ICSI incubation times differ considerably both between and within assisted reproduction facilities. There is no established consensus on the optimal sperm incubation timings to maximize pregnancy rates, and the few studies addressing this association rely on manual and operator-dependent methods for time recording. The present retrospective cohort study includes 1169 ICSI cycles using fresh semen processed by swim-up.

Barriers and factors associated with significant delays to initial consultation and treatment for infertile patients and partners of infertile patients.

Research Question: What are the key drivers and barriers for infertile patients and their partners to see an infertility specialist and initiate treatment?

Design: An online, international, 30-minute quantitative survey collected data from 1944 respondents from nine countries. Respondents were infertile patients (n = 1037) or partners of infertile patients (n = 907; but not necessarily partners of the patient sample), at different stages of the treatment journey.

Results: The overall average times were 3.

The human sperm basal body is a complex centrosome important for embryo preimplantation development.

The mechanism of conversion of the human sperm basal body to a centrosome after fertilization, and its role in supporting human early embryogenesis, has not been directly addressed so far. Using proteomics and immunofluorescence studies, we show here that the human zygote inherits a basal body enriched with centrosomal proteins from the sperm, establishing the first functional centrosome of the new organism. Injection of human sperm tails containing the basal body into human oocytes followed by parthenogenetic activation, showed that the centrosome contributes to the robustness of the early cell divisions, increasing the probability of parthenotes reaching the compaction stage.

Human oocyte meiotic maturation is associated with a specific profile of alternatively spliced transcript isoforms.

The transition from a transcriptionally active state (GV) to a transcriptionally inactive state (mature MII oocytes) is required for the acquisition of oocyte developmental competence. We hypothesize that the expression of specific genes at the in vivo matured (MII) stage could be modulated by posttranscriptional mechanisms, particularly regulation of alternative splicing (AS). In this study, we examined the transcriptional activity of GV oocytes after ovarian stimulation followed by oocyte pick-up and the landscape of alternatively spliced isoforms in human MII oocytes.

A microfluidic sperm-sorting device reduces the proportion of sperm with double-stranded DNA fragmentation.

Sperm DNA fragmentation can be produced in one (ssSDF) or both (dsSDF) DNA strands, linked to difficulties in naturally achieving a pregnancy and recurrent miscarriages, respectively. The techniques more frequently used to select sperm require centrifugation, which may induce sperm DNA fragmentation (SDF). The objective of this study was to assess whether the microfluidic-based device FertileChip® (now ZyMot®ICSI) can diminish the proportion of sperm with dsSDF.

Sperm donation: an alternative to improve post-ICSI live birth rates in advanced maternal age patients.

Study Question: Can sperm donation increase live birth rates following ICSI in advanced maternal age (AMA) patients?

Summary Answer: Sperm donation increases the live birth rate in AMA ICSI cycles.

What Is Known Already: In ICSI practice, sperm donation has been predominantly applied to overcome male infertility. The involvement of paternal age and lower sperm quality in the severe reduction in fertility observed in AMA patients remains to be clarified.

Reproductive Outcomes in Lesbian Couples Undergoing Reception of Oocytes from Partner Versus Autologous Fertilization/Intracytoplasmic Sperm Injection.

This study aimed to compare reproductive outcomes after Reception of Oocytes from Partner (ROPA; also called reciprocal fertilization) with those after fertilization/intracytoplasmic sperm injection (IVF/ICSI) with autologous oocytes, in lesbian couples. This was a retrospective matched cohort study of couples performing a first cycle of either ROPA ( = 60) or autologous IVF/ICSI ( = 120) between February 2012 and May 2018. Couples were matched 1:2 by age of the oocyte provider, day of embryo transfer (ET), and number of embryos transferred.