-
Human Reproduction Open 2024Is pronuclear transfer (PNT) capable of restoring embryo developmental arrest caused by cytoplasmic inferiority of -grown (IVG) mouse oocytes?
STUDY QUESTION
Is pronuclear transfer (PNT) capable of restoring embryo developmental arrest caused by cytoplasmic inferiority of -grown (IVG) mouse oocytes?
SUMMARY ANSWER
PNT to matured cytoplasm significantly improved embryo development of IVG mouse oocytes, leading to living, fertile offspring.
WHAT IS KNOWN ALREADY
follicle culture has been considered as a fertility preservation option for cancer patients. Studies describing the culture of human follicles remain scarce, owing to low availability of tissue. Mouse models have extensively been used to study and optimize follicle culture. Although important achievements have been accomplished, including the production of healthy offspring in mice, IVG oocytes are of inferior quality when compared to -grown oocytes, likely because of cytoplasmic incompetence.
STUDY DESIGN SIZE DURATION
The study was carried out from September 2020 to February 2022. In total, 120 15-day-old B6D2 mice were used to perform secondary follicle culture and assess the quality of IVG oocytes. -grown control oocytes were obtained from 85 8- to 12-week-old B6D2 mice, following ovarian stimulation. For sperm collection, four B6D2 males between 10 and 14 weeks old were used. For embryo transfer, 14 8- to 12-week-old CD1 females served as surrogate mothers and 10 CD1 vasectomized males 10-24 weeks old were used to generate pseudo-pregnant females. Finally, for mating, four B6D2 female mice aged 8-10 weeks and two B6D2 male mice aged 10 weeks old were used to confirm the fertility of nuclear transfer (NT)-derived pups.
PARTICIPANTS/MATERIALS SETTING METHODS
Secondary follicles from 15-day-old B6D2 mice were isolated from the ovaries and cultured for 9 days, before a maturation stimulus was given. Following 16-18 h of maturation, oocytes were collected and evaluated on maturation rate, oocyte diameter, activation rate, spindle morphology, calcium-releasing ability, and mitochondrial membrane potential. For every experiment, -grown oocytes were used as a control for comparison. When cytoplasmic immaturity and poor embryo development were confirmed in IVG oocytes, PNT was performed. For this, the pronuclei from IVG oocytes, created following parthenogenetic activation and IVF, were transferred to the cytoplasm of fertilized, -grown oocytes. Genetic analysis and embryo transfer of the generated embryos were implemented to confirm the safety of the technique.
MAIN RESULTS AND THE ROLE OF CHANCE
Following 9 days of follicle culture, 703 oocytes were collected, of which 76% showed maturation to the metaphase II stage. Oocyte diameters were significantly lower in IVG oocytes, measuring 67.4 μm versus 73.1 μm in controls ( < 0.001). Spindle morphology did not differ significantly between IVG and control oocytes, but calcium-releasing ability was compromised in the IVG group. An average calcium release of 1.62 arbitrary units was observed in IVG oocytes, significantly lower than 5.74 in control oocytes ( < 0.001). Finally, mitochondrial membrane potential was inferior in IVG compared to the control group, reaching an average value of 0.95 versus 2.27 ( < 0.001). Developmental potential of IVG oocytes was assessed following parthenogenetic activation with strontium chloride (SrCl). Only 59.4% of IVG oocytes cleaved to two cells and 36.3% reached the blastocyst stage, significantly lower than 89.5% and 88.2% in control oocytes, respectively ( < 0.001 and 0.001). Both PNT and spindle transfer (ST) were explored in pilot experiments with parthenogenetically activated oocytes, as a means to overcome poor embryo development. After the added value of NT was confirmed, we continued with the generation of biparental embryos by PNT. For this purpose, IVG and control oocytes first underwent IVF. Only 15.5% of IVG oocytes were normally fertilized, in contrast to 45.5% in controls ( < 0.001), with resulting failure of blastocyst formation in the IVG group (0 versus 86.2%, < 0.001). When the pronuclei of IVG zygotes were transferred to the cytoplasm of control zygotes, the blastocyst rate was restored to 86.9%, a similar level as the control. Genetic analysis of PNT embryos revealed a normal chromosomal profile, to a rate of 80%. Finally, the generation of living, fertile offspring from PNT was possible following embryo transfer to surrogate mothers.
LARGE-SCALE DATA
N/A.
LIMITATIONS REASONS FOR CAUTION
Genetic profiles of analysed embryos from PNT originate from groups that are too small to draw concrete conclusions, whilst ST, which would be the preferred NT approach, could not be used for the generation of biparental embryos owing to technical limitations. Even though promising, the use of PNT should be considered as experimental. Furthermore, results were acquired in a mouse model, so validation of the technique in human IVG oocytes needs to be performed to evaluate the clinical relevance of the technology. The genetic profiles from IVG oocytes, which would be the ultimate characterization for chromosomal abnormalities, were not analysed owing to limitations in the reliable analysis of single cells.
WIDER IMPLICATIONS OF THE FINDINGS
PNT has the ability to overcome the poor cytoplasmic quality of IVG mouse oocytes. Considering the low maturation efficiency of human IVG oocytes and potential detrimental effects following long-term culture, NT could be applied to rescue embryo development and could lead to an increased availability of good quality embryos for transfer.
STUDY FUNDING/COMPETING INTERESTS
A.C. is a holder of FWO (Fonds voor Wetenschappelijk Onderzoek) grants (1S80220N and 1S80222N). B.H. and A.V.S. have been awarded with a special BOF (Bijzonder Onderzoeksfonds), GOA (Geconcerteerde onderzoeksacties) 2018000504 (GOA030-18 BOF) funding. B.H. has been receiving unrestricted educational funding from Ferring Pharmaceuticals (Aalst, Belgium). The authors declare that they have no conflict of interest.
PubMed: 38425578
DOI: 10.1093/hropen/hoae009 -
EMBO Reports Apr 2024Stabilization of microtubule plus end-directed kinesin CENP-E at the metaphase kinetochores is important for chromosome alignment, but its mechanism remains unclear....
Stabilization of microtubule plus end-directed kinesin CENP-E at the metaphase kinetochores is important for chromosome alignment, but its mechanism remains unclear. Here, we show that CKAP5, a conserved microtubule plus tip protein, regulates CENP-E at kinetochores in human cells. Depletion of CKAP5 impairs CENP-E localization at kinetochores at the metaphase plate and results in increased kinetochore-microtubule stability and attachment errors. Erroneous attachments are also supported by computational modeling. Analysis of CKAP5 knockout cancer cells of multiple tissue origins shows that CKAP5 is preferentially essential in aneuploid, chromosomally unstable cells, and the sensitivity to CKAP5 depletion is correlated to that of CENP-E depletion. CKAP5 depletion leads to reduction in CENP-E-BubR1 interaction and the interaction is rescued by TOG4-TOG5 domain of CKAP5. The same domain can rescue CKAP5 depletion-induced CENP-E removal from the kinetochores. Interestingly, CKAP5 depletion facilitates recruitment of PP1 to the kinetochores and furthermore, a PP1 target site-specific CENP-E phospho-mimicking mutant gets stabilized at kinetochores in the CKAP5-depleted cells. Together, the results support a model in which CKAP5 controls mitotic chromosome attachment errors by stabilizing CENP-E at kinetochores and by regulating stability of the kinetochore-attached microtubules.
Topics: Humans; Kinetochores; Chromosomal Proteins, Non-Histone; Microtubules; Metaphase; Kinesins; HeLa Cells; Mitosis; Chromosome Segregation; Microtubule-Associated Proteins
PubMed: 38424231
DOI: 10.1038/s44319-024-00106-9 -
Molecular Biology and Evolution Mar 2024Polyploidy, a significant catalyst for speciation and evolutionary processes in both plant and animal kingdoms, has been recognized for a long time. However, the exact...
Polyploidy, a significant catalyst for speciation and evolutionary processes in both plant and animal kingdoms, has been recognized for a long time. However, the exact molecular mechanism that leads to polyploid formation, especially in vertebrates, is not fully understood. Our study aimed to elucidate this phenomenon using the zebrafish model. We successfully achieved an effective knockout of the cyclin N-terminal domain containing 1 (cntd1) using CRISPR/Cas9 technology. This resulted in impaired formation of meiotic crossovers, leading to cell-cycle arrest during meiotic metaphase and triggering apoptosis of spermatocytes in the testes. Despite these defects, the mutant (cntd1-/-) males were still able to produce a limited amount of sperm with normal ploidy and function. Interestingly, in the mutant females, it was the ploidy not the capacity of egg production that was altered. This resulted in the production of haploid, aneuploid, and unreduced gametes. This alteration enabled us to successfully obtain triploid and tetraploid zebrafish from cntd1-/- and cntd1-/-/- females, respectively. Furthermore, the tetraploid-heterozygous zebrafish produced reduced-diploid gametes and yielded all-triploid or all-tetraploid offspring when crossed with wild-type (WT) or tetraploid zebrafish, respectively. Collectively, our findings provide direct evidence supporting the crucial role of meiotic crossover defects in the process of polyploidization. This is particularly evident in the generation of unreduced eggs in fish and, potentially, other vertebrate species.
Topics: Male; Animals; Female; Triploidy; Zebrafish; Tetraploidy; Seeds; Polyploidy; Ploidies
PubMed: 38421617
DOI: 10.1093/molbev/msae047 -
Biomolecules Feb 2024P21-activated kinase 1 (PAK1) is a critical downstream target that mediates the effect of small Rho GTPase on the regulation of cytoskeletal kinetics, cell...
P21-activated kinase 1 (PAK1) is a critical downstream target that mediates the effect of small Rho GTPase on the regulation of cytoskeletal kinetics, cell proliferation, and cell migration. PAK1 has been identified as a crucial regulator of spindle assembly during the first meiotic division; however, its roles during the metaphase I (MI) to metaphase II (MII) transition in oocytes remain unclear. In the present study, the potential function of PAK1 in regulating microtubule organization and spindle positioning during the MI-MII transition was addressed in porcine oocytes. The results showed that activated PAK1 was co-localized with α-tubulin, and its expression was increased from the MI to MII stage ( < 0.001). However, inhibiting PAK1 activity with an inhibitor targeting PAK1 activation-3 (IPA-3) at the MI stage decreased the first polar body (PB1) extrusion rate ( < 0.05), with most oocytes arrested at the anaphase-telophase (ATI) stage. IPA-3-treated oocytes displayed a decrease in actin distribution in the plasma membrane ( < 0.001) and an increase in the rate of defects in MII spindle reassembly with abnormal spindle positioning ( < 0.001). Nevertheless, these adverse effects of IPA-3 on oocytes were reversed when the disulfide bond between PAK1 and IPA-3 was reduced by dithiothreitol (DTT). Co-immunoprecipitation revealed that PAK1 could recruit activated Aurora A and transform acidic coiled-coil 3 (TACC3) to regulate spindle assembly and interact with LIM kinase 1 (LIMK1) to facilitate actin filament-mediated spindle migration. Together, PAK1 is essential for microtubule organization and spindle migration during the MI-MII transition in porcine oocytes, which is associated with the activity of p-Aurora A, p-TACC3 and p-LIMK1.
Topics: Animals; Cell Cycle Proteins; Metaphase; Microtubules; Oocytes; p21-Activated Kinases; Spindle Apparatus; Swine
PubMed: 38397472
DOI: 10.3390/biom14020237 -
Cellular and Molecular Life Sciences :... Feb 2024Cell division is a crucial process, and one of its essential steps involves copying the genetic material, which is organized into structures called chromosomes. Before a... (Review)
Review
Cell division is a crucial process, and one of its essential steps involves copying the genetic material, which is organized into structures called chromosomes. Before a cell can divide into two, it needs to ensure that each newly copied chromosome is paired tightly with its identical twin. This pairing is maintained by a protein complex known as cohesin, which is conserved in various organisms, from single-celled ones to humans. Cohesin essentially encircles the DNA, creating a ring-like structure to handcuff, to keep the newly synthesized sister chromosomes together in pairs. Therefore, chromosomal cohesion and separation are fundamental processes governing the attachment and segregation of sister chromatids during cell division. Metaphase-to-anaphase transition requires dissolution of cohesins by the enzyme Separase. The tight regulation of these processes is vital for safeguarding genomic stability. Dysregulation in chromosomal cohesion and separation resulting in aneuploidy, a condition characterized by an abnormal chromosome count in a cell, is strongly associated with cancer. Aneuploidy is a recurring hallmark in many cancer types, and abnormalities in chromosomal cohesion and separation have been identified as significant contributors to various cancers, such as acute myeloid leukemia, myelodysplastic syndrome, colorectal, bladder, and other solid cancers. Mutations within the cohesin complex have been associated with these cancers, as they interfere with chromosomal segregation, genome organization, and gene expression, promoting aneuploidy and contributing to the initiation of malignancy. In summary, chromosomal cohesion and separation processes play a pivotal role in preserving genomic stability, and aberrations in these mechanisms can lead to aneuploidy and cancer. Gaining a deeper understanding of the molecular intricacies of chromosomal cohesion and separation offers promising prospects for the development of innovative therapeutic approaches in the battle against cancer.
Topics: Humans; Cell Cycle Proteins; Chromosomal Proteins, Non-Histone; Cohesins; Chromatids; Carcinogenesis; Cell Transformation, Neoplastic; Neoplasms; Chromosome Segregation; Aneuploidy; Genomic Instability
PubMed: 38388697
DOI: 10.1007/s00018-024-05122-5 -
JBRA Assisted Reproduction Feb 2024Previous studies have shown that the meiotic spindle is not always aligned with the first polar body (PB) in metaphase II human oocytes. Polarized Light Microscopy (PLM)...
OBJECTIVE
Previous studies have shown that the meiotic spindle is not always aligned with the first polar body (PB) in metaphase II human oocytes. Polarized Light Microscopy (PLM) has been used to observe and locate the meiotic spindle to avoid disrupting it while injecting oocytes. The aim of this study is to evaluate the relationship between meiotic spindle view and IVF-ICSI outcomes in poor responder women.
METHODS
This study was a retrospective analytical study, carried out from January to November 2019; involving 115 poor responder women who underwent IVF-ICSI cycles at the Halim Fertility Center, Indonesia. The patients were divided into two groups: group I without meiotic spindle viewing (non-MSV) as control group, and group II with meiotic spindle viewing (MSV) as the case group. The meiotic spindles were imaged before ICSI with Oosight microscopy. Baseline characteristics and IVF-ICSI outcomes of both groups were compared.
RESULTS
Our study included 115 poor responder women with non-MSV group (71 women), and an MSV group (44 women). The results showed that there was no significant difference in the fertilization rate between the two groups (p>0.05), but the embryo cleavage rate was higher in the MSV group when compared to the non-MSV group; and there was a significant difference between the two groups (p<0.05). The fertilization rate was higher in aligned than misaligned spindle and there was a significant difference between the two groups (p<0.05). Good quality embryo was higher in MSV group than non-MSV group (59.05% vs. 63.95%).
CONCLUSIONS
Meiotic spindle view might improve the outcome of IVF in poor responder women.
Topics: Humans; Female; Fertilization in Vitro; Sperm Injections, Intracytoplasmic; Retrospective Studies; Indonesia; Oocytes; Spindle Apparatus
PubMed: 38381774
DOI: 10.5935/1518-0557.20240006 -
Human Reproduction Open 2024Does a matrix-free culture system supplemented with neurotrophic factor 4 (NT4) improve human follicular development and meiotic maturation, ultimately resulting in...
STUDY QUESTION
Does a matrix-free culture system supplemented with neurotrophic factor 4 (NT4) improve human follicular development and meiotic maturation, ultimately resulting in fertilizable oocytes?
SUMMARY ANSWER
NT4 supplementation of culture significantly enhances the growth, steroid hormone production, and maturity potential of human secondary follicles derived from fresh ovarian medulla (from post- and pre-pubertal patients), thereby yielding fertilizable oocytes.
WHAT IS KNOWN ALREADY
Reconstituting folliculogenesis is of paramount importance in the realms of fertility preservation, reproductive biology research, and reproductive toxicity assessments. However, the efficiency of culture systems remains suboptimal, as the attainment of fertilizable oocytes from growth (IVG) of human follicles remains unachieved, with the data being particularly scant regarding follicles from prepubertal girls. We have previously found that mouse oocytes from secondary follicles derived from IVG are deficient in neuroendocrine regulation. NT4 and its corresponding receptor have been identified in human follicles. Significantly, the addition of NT4 during the IVG process markedly enhances both follicle growth and oocyte maturation rates in mice.
STUDY DESIGN SIZE DURATION
Fresh medulla tissue obtained during tissue preparation for ovarian tissue cryopreservation (OTC) were collected from 10 patients aged from 6 to 21 years old, all of whom had undergone unilateral oophorectomy as a means of fertility preservation. Isolated secondary follicles were individually cultured with or without NT4 in a matrix-free system.
PARTICIPANTS/MATERIALS SETTING METHODS
Secondary follicles, extracted via enzymatic digestion and mechanical disruption from each patient, were randomly allocated to either a control group or an NT4-supplemented group (100 ng/ml), followed by individual culture on an ultra-low attachment plate. Follicle growth and viability were assessed by microscopy. Levels of anti-Müllerian hormone (AMH), estradiol, and progesterone in the medium were quantified. An oocyte-specific marker was identified using confocal fluorescence microscopy following DEAD box polypeptide 4 (DDX4) staining. The competence of individual oocytes for maturation and fertilization were assessed after IVM and ICSI with donated sperm samples.
MAIN RESULTS AND THE ROLE OF CHANCE
Overall, isolated follicles from both groups survived up to 6 weeks with increasing diameters over the duration ( < 0.05), reaching terminal diameters of almost 1 mm with confirmed steroidogenesis and expression of oocyte marker (DDX4), and producing morphologically normal MII oocytes. When compared with the control group, the NT4 group had a similar initial follicular diameter (206 ± 61.3 vs 184 ± 93.4 μm) but exhibited a significant increase in follicular diameter from the ninth day of culture onwards ( < 0.05). From Week 3, estradiol and progesterone production were significantly increased in the NT4 group, while no significant difference was observed in AMH production between groups. The proportion of 'fast-growth' follicles in the NT4 group was significantly higher than that in the control group (13/23 vs 6/24, < 0.05). An increased efficiency of MII oocyte maturation per live follicle in the NT4 group was also observed (control group vs NT4 group, 4/24 vs 10/23, < 0.05). It is noteworthy that an MII oocyte obtained from the control group exhibited abnormal fertilization after ICSI. In contrast, an MII oocyte acquired from the NT4 group progressed to the blastocyst stage and showed potential for transfer.
LARGE SCALE DATA
N/A.
LIMITATIONS REASONS FOR CAUTION
The cohort examined in this study was all patients diagnosed with beta-thalassemia major. Whether this culture system is effective for patients with other diseases remains unknown. Since the chosen dose of NT4 was established based on dose finding in mice, the optimal dose for use in a human IVG system needs further confirmation. The oocytes and embryos procured from this study have not been quantified for ploidy status or epigenetic signatures.
WIDER IMPLICATIONS OF THE FINDINGS
Fresh medulla tissue obtained during tissue preparation for OTC may serve as a precious source of fertilizable oocytes for female fertility preservation, even for pre-pubertal girls, without the threat of tumour reintroduction. After further characterization and optimization of the system, this culture system holds the potential to provide a powerful future research tool, for the comprehensive exploration of human follicular development mechanisms and for conducting reproductive toxicity evaluations.
STUDY FUNDING/COMPETING INTERESTS
This work was supported by the National Key R&D Program of China (grant number 2022YFC2703000) and National Natural Science Foundation of China (grant numbers 82271651 and 81871214). The medium used in human follicle culture in this study has been applied for a national invention patent in China (No. 202211330660.7). The inventors of the patent, in order, are: Y.G., C.F., and X.L.
PubMed: 38371224
DOI: 10.1093/hropen/hoae005 -
International Journal of Reproductive... Dec 2023Overweight and obese people face several health problems. Female obesity has been shown to reduce fertility in the general population. Assisted reproductive technology...
BACKGROUND
Overweight and obese people face several health problems. Female obesity has been shown to reduce fertility in the general population. Assisted reproductive technology outcomes in obese cases are widely studied, but the results are inconclusive.
OBJECTIVE
This study aimed to compare live birth rate (LBR) among women with 4 different types of body mass index (BMI).
MATERIALS AND METHODS
In this cross-sectional study, data of 1611 women, who were candidates for fresh and frozen embryo transfer cycles, was extracted from 2051 medical files at the Reproductive Sciences Institute, Yazd, Iran from May 2019-May 2021. The participants were divided into 4 groups (underweight, normal, overweight, and obese) according to their BMI, and LBR was considered to be the main outcome.
RESULTS
Of 1611 women, 39 were underweight, 585 were normal, 676 were overweight, and 311 were obese. Underweight women had the lowest LBR (12.8%), but there was no statistically significant difference (p = 0.55). In addition, LBR was compared in the 4 BMI groups according to age, type of transfer cycle (fresh or freeze), and cause of infertility, and there was comparable LBR in the 4 BMI groups. However, metaphase 2 oocyte rate, doses of gonadotropin usage in the cycles, and estradiol level had statistically significant differences (p 0.001).
CONCLUSION
According to our study, obesity does not affect LBR in the IVF cycle, regardless of fresh or frozen embryo transfer cycles, different age groups, and causes of infertility.
PubMed: 38370492
DOI: 10.18502/ijrm.v21i12.15040 -
International Journal of Fertility &... Feb 2024It is difficult to obtain healthy oocytes in poor ovarian responders with conventional treatment methods. Thus, the need to investigate new methods is essential. This...
Investigating Ovulation Induction Outcomes in Patients with Decreased Ovarian Reserve Treated with Double Stimulation during The Follicular and Luteal Phases Compared to The Conventional Antagonist Cycle: A Randomized Clinical Trial.
BACKGROUND
It is difficult to obtain healthy oocytes in poor ovarian responders with conventional treatment methods. Thus, the need to investigate new methods is essential. This study aims to investigate ovulation induction outcomes in patients with decreased ovarian reserve (DOR) in two groups treated with double stimulation (DuoStim) during the follicular and luteal phases in comparison with the antagonist cycle.
MATERIALS AND METHODS
This was a randomised clinical trial that enrolled the patients with reduced ovarian reserve. The patients referred for in vitro fertilization (IVF) at Molud Infertility Clinic, Ali Ebn Abitalib (AS) Hospital, Zahedan, Iran from 2020 to 2021. Participants were randomly divided into two groups, those who underwent treatment with DuoStim during the follicular and luteal phase (case group) and those who received the conventional antagonist cycle (control group).
RESULTS
The mean number of metaphase II (MII) eggs was 7.7 ± 3.1 in the case group and 6.1 ± 3.9 in the control group (P=0.063). The mean total number of retrieved eggs in the case group was 9.2 ± 3.7 and in the control group, it was 6.9 ± 4.4 (P=0.023). The mean number of embryos obtained in the case group was 6.5 ± 3.9; in the control group, it was 4.7 ± 2.8 (P=0.016).
CONCLUSION
The DuoStim method can effectively play a role in increasing the total number of retrieved eggs and embryos (registration number: IRCT20120817010617N8).
PubMed: 38368517
DOI: 10.22074/ijfs.2023.1978181.1405 -
International Journal of Fertility &... Feb 2024Various protocols have been approved to improve the response rate leading to successful fertilization in poor ovarian responders (PORs). The application of double...
BACKGROUND
Various protocols have been approved to improve the response rate leading to successful fertilization in poor ovarian responders (PORs). The application of double ovarian stimulation (DuoStim) in the follicular and luteal phases of the same ovarian cycle has been shown as an intriguing option to achieve more oocyte retrievals in the shortest time. The aim of the current study is to compare the outcomes of different protocols, minimal stimulation (MS) and Duostim.
MATERIALS AND METHODS
This randomized clinical trial was performed on 42 fertilization (IVF) candidates with POR diagnosis. Patients were classified into two equal groups and treated with the DuoStim protocol and MS protocol. The IVF outcomes, including retrieved follicles, oocytes, metaphase II (MII) oocytes and embryos, were compared between these groups.
RESULTS
The patients' characteristics including age, anti-mullerian hormone (AMH), follicle stimulating hormone (FSH), luteinizing hormone (LH), and antral follicle count (AFC) were collected and compared. It showed there was no significant difference between the two groups baseline characteristics (P>0.05). We observed that the DuoStim protocol resulted in a significantly higher score in comparison with the MS protocols , including the number of follicles (6.23 ± 2.93 vs. 1.77 ± 1.66, P<0.001), retrieved oocytes (3.86 ± 2.57 vs. 1.68 ± 1.58, P=0.002), MII oocytes (3.36 ± 2.42 vs. 1.27 ± 1.27, P=0.001) and obtained embryos (2.04 ± 1.64 vs. 0.77 ± 0.86, P=0.003).
CONCLUSION
The DuoStim protocol is a favourable and time saving plan that is associated with more oocytes in a single stimulation cycle. The DuoStim protocol significantly can result in more frequent MII oocytes and embryos. We figured that the higher number of oocytes and embryos might have led to a higher rate of pregnancy (registration number: IRCT20200804048303N1).
PubMed: 38368516
DOI: 10.22074/ijfs.2023.552687.1293