pronuclear embryo

PURPOSE: To evaluate live birth rates (LBRs) for in vitro fertilization (IVF) cycles with ≤5 follicles at trigger, with the goal of helping patients with low follicle counts decide whether to proceed to retrieval. METHODS: This is a retrospective cohort study from an urban, university-affiliated fertility center. All IVF cycles that yielded <10 oocytes between 2016 and 2020 were reviewed. Cycles were included if <5 follicles measuring >14 mm were verified on trigger day...

STUDY QUESTION: Does double vitrification and thawing of an embryo compromise the chance of live birth after a single blastocyst transfer? SUMMARY ANSWER: The live birth rate (LBR) obtained after double vitrification was comparable to that obtained after single vitrification. WHAT IS KNOWN ALREADY: Double vitrification-warming (DVW) is commonly practiced to accommodate surplus viable embryos suitable for transfer, to allow retesting of inconclusively diagnosed blastocysts in preimplantation genetic testing (PGT), and to circumvent limitations associated with national policies on embryo culture in certain countries...

Human IVF embryos that are not used for fresh transfer are cryopreserved by vitrification for later embryo transfers. This study evaluates pre-vitrification and post-warming embryo characteristics that are suitable to predict the chance of clinical pregnancy in single vitrified blastocyst transfer (SVBT) cycles. In a multicenter observational trial (IMBOS trial), embryos were cultured in a time-lapse system before and after vitrification. Associations between clinical pregnancy, morphokinetic parameters, blastocyst collapse, KIDScore D5, pre-vitrification and post-warming Gardner scores, post-warming blastocyst size and re-expansion rates before SVBT were analyzed in 182 SVBTs which resulted in 89 clinical pregnancies...

RESEARCH QUESTION: Is high sperm DNA fragmentation (SDF) associated with a high embryonic aneuploidy rate in patients undergoing intracytoplasmic sperm injection (ICSI)-preimplantation genetic testing (PGT)? DESIGN: This was a retrospective study of 426 couples with normal karyotypes undergoing ICSI-PGT at the authors' centre from March 2017 to March 2021. SDF was assessed using the sperm chromatin structure assay. The population was divided into low and high SDF groups according to cut-off values found by the receiver operating characteristic (ROC) curve...

BACKGROUND: Previous studies have reported that after laparoscopic cystectomy of ovarial endometrioma, the ovarian response to gonadotropin (Gn) significantly decreased. However, for patients with diminished ovarian reserve (DOR) after ovarian surgery, how to choose the most appropriate controlled ovarian hyperstimulation protocol has not been concluded. Compared with the traditional agonist regimen, the gonadotropin (Gn)-releasing hormone (GnRH) antagonist, microstimulation, and progestin-primed ovarian stimulation (PPOS) protocols are simple to operate and have a shorter cycle, which are often used in patients with DOR...

Nuclear maturation is an essential process in which oocytes acquire the competence to develop further. However, the time required for nuclear maturation during IVM varies among oocytes. Therefore, predicting nuclear maturation speed (NMS) could help identify the optimal timing for IVF and maximize the developmental competence of each oocyte. This study aimed to establish machine learning-based prediction models for NMS using non-invasive indicators during the individual IVM of Japanese Black (JB) beef heifer oocytes...

PURPOSE: To investigate the clinical outcomes of in vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI) cycles using frozen-thawed blastocyst transfers derived from zygotes with no (0PN) or one pronucleus (1PN). METHODS: This retrospective study included 7084 0PN, 2238 1PN, and 72,266 two pronuclear (2PN) embryos cultured to the blastocyst stage from 19,631 IVF and 12,377 ICSI cycles between March 2018 and December 2021. Developmental potential and clinical outcomes of 0PN, 1PN, and 2PN embryos were analyzed...

STUDY QUESTION: What clinical and laboratory differences emerge from parallel direct comparison of embryos reaching the blastocyst stage between Days 4, 5, 6, and 7 (Days 4-7)? SUMMARY ANSWER: Increasing times to blastocyst formation are associated with a worse clinical outcome and perturbations in developmental patterns appear as early as the fertilization stage. WHAT IS KNOWN ALREADY: Previous evidence indicates that later times to blastocyst development are associated with a worse clinical outcome...

Superovulation procedures are routinely and widely used in mouse reproductive technology. Previous studies have shown that a large number of oocytes can be obtained from adult mice (> 10 weeks old) using a combined treatment with progesterone (P4) and anti-inhibin serum (AIS). However, these effects have not been fully investigated in young (4 weeks) C57BL/6J mice. Here, we found that a modified superovulation protocol (combined treatment with P4, AIS, eCG (equine chorionic gonadotropin), and hCG (human chorionic gonadotropin); P4D2-Ae-h) improved the number of oocytes compared to the control (eCG and hCG) (39...

BACKGROUND: Oocyte degeneration was mostly described in intracytoplasmic sperm injection (ICSI) cycles; there is no report showing the relationship between oocyte degeneration and clinical outcomes in conventional in vitro fertilization (IVF) cycles. This retrospective study using the propensity score (PS) matching method aimed to explore whether the presence of oocyte degeneration in conventional IVF cycles would affect the sibling embryo development potential and clinical outcomes. METHODS: Patients with at least one oocyte degenerated after short-term insemination and stripping were defined as the degeneration (DEG) group, while patients with no oocyte degenerated were defined as the non-degeneration (NONDEG) group...

PURPOSE: What is the rate of euploidy and clinical viability of embryos resulting from micro 3 pronuclei zygotes? METHODS: Retrospective cohort analysis in a single, academic in vitro fertilization (IVF) center from March 2018 to June 2021. Cohorts were separated by fertilization as either a 2 pronuclear zygote (2PN) or micro 3 pronuclear zygote (micro 3PN). PGT-A was performed to identify embryonic ploidy rates in embryos created from micro 3PN zygotes. The clinical outcomes of all transferred euploid micro 3PN zygotes were evaluated from frozen embryo transfer (FET) cycles...

PURPOSE: To investigate the association between oocyte area and fertilization rate, embryo usage, and preimplantation embryo development in order to establish if oocyte area can be a marker for optimal early embryo development. METHODS: From 2017 to 2020, 378 couples with an indication for IVF (n = 124) or ICSI (n = 254) were included preconceptionally in the Rotterdam Periconception Cohort. Resulting oocytes (n = 2810) were fertilized and submitted to time-lapse embryo culture...

During mammalian fertilization, repetitive rises of intracellular calcium called calcium oscillations are required for full activation of oocytes. Therefore, oocytes such as round spermatid injected or somatic cell nuclear transferred require additional artificial activation which mimics the calcium oscillations. It is well recognized that sperm specific phospholipase C (PLCζ) is a strong candidate as the sperm factor which can induce calcium oscillations and, at least in mammals, the genetic mutation of PLCζ in human causes male infertility due to the lack of calcium oscillations in the oocytes...

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...

A dearth of evidence exists on embryos derived from oocytes without two pronuclei (2PN) or 'normal fertilization', i.e. embryos arising from non-pronuclear oocytes (0PN), mono-pronuclear oocytes (1PN) and tri-pronuclear oocytes (3PN). We searched the published literature on non-2PN oocytes and their clinical outcomes using a two-part collection strategy of relevant articles. A total of 33 articles were deemed eligible for the scoping review. A significant difference exists between potential development of oocytes with an abnormal number of pronuclei and those with 2PN in most studies; the abnormal pronuclei oocytes occur rarely and significant attrition occurs between day 1 and day 6, with corresponding reduction in chromosome integrity and clinical utility...

Genetic engineering in the rat has been revolutionized by the development of CRISPR-based genome editing tools. Conventional methods for inserting genome editing elements such as CRISPR/Cas9 reagents into rat zygotes include cytoplasmic or pronuclear microinjections. These techniques are labor-intensive, require specialized micromanipulator equipment, and are technically challenging. Here, we describe a simple and effective method for zygote electroporation in which CRISPR/Cas9 reagents are introduced into rat zygotes via pores produced by precise electrical pulses applied to the cells...

Oocyte-mediated somatic cell haploidization is a process in which a diploid cell halves its chromosomal content by segregating its homologue within the ooplasm. Replacing the donor oocyte nucleus with a patient's female diploid somatic nucleus can generate patient-genotyped oocytes. Insemination of these resulting constructs enables their activation and induces a reductive meiotic division, haploidizing the diploid female donor cell that can subsequently support syngamy with the male genome and create a zygote...

The present study investigated the effects of vitrification of porcine oocytes either at the immature Germinal Vesicle (GV) stage before in vitro maturation (GV-stage oocytes) or at the pronuclear stage after in vitro maturation and fertilization (zygotes) on DNA integrity in relevance with their subsequent embryo development. Vitrification at the GV stage but not at the pronuclear stage significantly increased the abundance of double-strand breaks (DSBs) in the DNA measured by the relative fluorescence after γH2AX immunostaining...

BACKGROUND: Resistant ovarian syndrome(ROS) is a rare disease. It is difficult to diagnose and treat. Most of the literature reports on assisted pregnancy treatment for ROS patients are individual case reports. In this paper, the ovulation stimulation protocol and assisted pregnancy process of ROS infertile patients in our reproductive center were summarized and analyzed to provide information and support for the clinical treatment of ROS patients. METHODS: From January 2017 to March 2022, assisted reproductive technology treatments and clinical characteristics parameters of six patients with ROS were retrospectively reviewed...

BACKGROUND: According to the latest practice committee document, in vitro maturation (IVM) is a simple and safe procedure, especially in patients with polycystic ovary syndrome (PCOS). Does switching from in vitro fertilization (IVF) to IVM (IVF/M) help as a rescue infertility treatment for PCOS patients with an unexpected poor ovarian response (UPOR) tendency? METHODS: This retrospective cohort study included 531 women with PCOS who had undergone 588 natural IVM cycles or had switched to IVF/M cycles from 2008 to 2017...