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BACKGROUND Monozygotic (MZ) twins are believed to arise from the fission of a single fertilized embryo at different stages. Monochorionic MZ twins, who share one chorion, originate from the splitting of the inner cell mass (ICM) within a single blastocyst. In the classic model for dichorionic MZ twins, the embryo splits before compaction, developing into two blastocysts. However, there are a growing number of ART cases where a single blastocyst transfer results in dichorionic MZ twins, indicating that embryo splitting may occur even after blastocyst formation. OBJECTIVE AND RATIONALE For monochorionic MZ twins, we conducted a comprehensive analysis of the cellular mechanisms involved in ICM splitting, drawing from both ART cases and animal experiments. In addition, we critically re-examine the classic early splitting model for dichorionic MZ twins. We explore cellular mechanisms leading to two separated blastocysts in ART, potentially causing dichorionic MZ twins. SEARCH METHODS Relevant studies including research articles, reviews, and conference papers were searched in the PubMed database. Cases of MZ twins from IVF clinics were found by using combinations of terms including 'monozygotic twins' with 'IVF case report', 'ART', 'single embryo transfer', or 'dichorionic'. The papers retrieved were categorized based on the implicated mechanisms or as those with unexplained mechanisms. Animal experiments relating to MZ twins were found using 'mouse embryo monozygotic twins', 'mouse 8-shaped hatching', 'zebrafish janus mutant', and 'nine-banded armadillo embryo', along with literature collected through day-to-day reading. The search was limited to articles in English, with no restrictions on publication date or species. OUTCOMES For monochorionic MZ twins, ART cases and mouse experiments demonstrate evidence that a looser ICM in blastocysts has an increased chance of ICM separation. Physical forces facilitated by blastocoel formation or 8-shaped hatching are exerted on the ICM, resulting in monochorionic MZ twins. For dichorionic MZ twins, the classic model resembles artificial cloning of mouse embryos in vitro , requiring strictly controlled splitting forces, re-joining prevention, and proper aggregation, which allows the formation of two separate human blastocysts under physiological circumstances. In contrast, ART procedures involving the transfer of a single blastocysts after atypical hatching or vitrified-warmed cycles might lead to blastocyst separation. Differences in morphology, molecular mechanisms, and timing across various animal model systems for MZ twinning can impede this research field. As discussed in future directions, recent developments of innovative in vitro models of human embryos may offer promising avenues for providing fundamental novel insights into the cellular mechanisms of MZ twinning during human embryogenesis. WIDER IMPLICATIONS Twin pregnancies pose high risks to both the fetuses and the mother. While single embryo transfer is commonly employed to prevent dizygotic twin pregnancies in ART, it cannot prevent the occurrence of MZ twins. Drawing from our understanding of the cellular mechanisms underlying monochorionic and dichorionic MZ twinning, along with insights into the genetic mechanisms, could enable improved prediction, prevention, and even intervention strategies during ART procedures. REGISTRAITON NUMBER N/A. [ABSTRACT FROM AUTHOR]

New, more efficient ways to accomplish objectives are key to improving the ability of zoological and conservation organizations to protect the animals they study and care for. Here, we describe an ovocesarean procedure, a novel task to assist the hatching of larval anurans in cases when allowing for hatching to occur naturally presents a risk to the survival of the progeny. This study focuses on two clutches of La Palma Glass Frogs (Hyalinobatrachium valerioi) where the eggs were not laid over a water body for the tadpoles to drop into upon emergence from the egg. A simple, three-step procedure that can be performed in just a few minutes resulted in a 95% success rate in emergence and led to increased survivability in the tadpoles that were assisted. Procedures that assist hatching of embryos and neonates are discussed in many circles of animal care but have not been described in detail to provide assistance to those that are not in a situation where they can learn it from a professional. This description of the ovocesarean procedure assigns a definitive, technical term to assisted hatching and can easily be extrapolated to other oviparous animals. Although the focal species here is of a Least Concern conservation status, this procedure can be key in improving reproductive success in other, more threatened species of anurans.

To evaluate whether laser-mediated assisted hatching (AH) performed on vitrified/warmed blastocysts before embryo transfer can improve live birth rate. The "pArtiaL zonA pelluciDa removal by assisteD hatchINg of blastocysts (ALADDIN)" is a 2-center comparative study with a parallel randomized controlled design. University hospital. Participants were recruited between September 2018 and November 2021. They were aged 18–39 years, underwent nondonor in vitro fertilization cycles, and were scheduled for elective single embryo transfer with vitrified/warmed blastocysts. Those with uterine abnormalities, body mass index of >35 kg/m2, severe male factor infertility, or performing preimplantation genetic testing were excluded. Assisted hatching was performed using a 1,480 nm diode laser, removing approximately one-third of the zona pellucida with continuous 0.2 ms pulses applied from the 1–5 o'clock positions. The primary outcome was the live birth rate. Secondary end points included clinical pregnancy, miscarriage, multiple pregnancies, preterm births, obstetric and neonatal complications, and congenital anomalies. Overall, 698 participants met the inclusion criteria and were randomized: 352 patients were assigned to the AH arm and 346 to the control arm. Of the participants, 105 (29.8%) and 101 (29.2%), respectively, achieved a live birth after treatment. The relative risk of live birth in patients with vitrified/warmed blastocysts treated with AH was 1.02 (95% confidence interval, 0.86–1.19). Exploratory subgroup analyses for women's age, recruiting centers, indications for in vitro fertilization, method of insemination, blastocyst quality, and days of blastocyst development failed to highlight any clinical situation that could benefit from AH in thawed blastocysts. In patients undergoing frozen embryo transfer with vitrified/warmed blastocysts, laser AH does not improve the live birth rate. Further studies are required to rule out milder but potentially interesting benefits in specific subgroups of patients. ClinicalTrials.gov: NCT03623659. [ABSTRACT FROM AUTHOR]

New, more efficient ways to accomplish objectives are key to improving the ability of zoological and conservation organizations to protect the animals they study and care for. Here, we describe an ovocesarean procedure, a novel task to assist the hatching of larval anurans in cases when allowing for hatching to occur naturally presents a risk to the survival of the progeny. This study focuses on two clutches of La Palma Glass Frogs (Hyalinobatrachium valerioi) where the eggs were not laid over a water body for the tadpoles to drop into upon emergence from the egg. A simple, three-step procedure that can be performed in just a few minutes resulted in a 95% success rate in emergence and led to increased survivability in the tadpoles that were assisted. Procedures that assist hatching of embryos and neonates are discussed in many circles of animal care but have not been described in detail to provide assistance to those that are not in a situation where they can learn it from a professional. This description of the ovocesarean procedure assigns a definitive, technical term to assisted hatching and can easily be extrapolated to other oviparous animals. Although the focal species here is of a Least Concern conservation status, this procedure can be key in improving reproductive success in other, more threatened species of anurans. [ABSTRACT FROM AUTHOR]

STUDY QUESTION Does assisted hatching increase the cumulative live birth rate in subfertile couples with repeated implantation failure? SUMMARY ANSWER This study showed no evidence of effect for assisted hatching as an add-on in subfertile couples with repeated implantation failure. WHAT IS KNOWN ALREADY The efficacy of assisted hatching, with regard to the live birth rate has not been convincingly demonstrated in randomized trials nor meta-analyses. It is suggested though that especially poor prognosis women, e.g. women with repeated implantation failure, might benefit most from assisted hatching. STUDY DESIGN, SIZE, DURATION The study was designed as a double-blinded, multicentre randomized controlled superiority trial. In order to demonstrate a statistically significant absolute increase in live birth rate of 10% after assisted hatching, 294 participants needed to be included per treatment arm, being a total of 588 subfertile couples. Participants were included and randomized from November 2012 until November 2017, 297 were allocated to the assisted hatching arm of the study and 295 to the control arm. Block randomization in blocks of 20 participants was applied and randomization was concealed from participants, treating physicians, and laboratory staff involved in the embryo transfer procedure. Ovarian hyperstimulation, oocyte retrieval, laboratory procedures, embryo selection for transfer and cryopreservation, the transfer itself, and luteal support were performed according to local protocols and were identical in both the intervention and control arm of the study with the exception of the assisted hatching procedure which was only performed in the intervention group. The laboratory staff performing the assisted hatching procedure was not involved in the embryo transfer itself. PARTICIPANTS/MATERIALS, SETTING, METHODS Participants were eligible for inclusion in the study after having had either at least two consecutive fresh IVF or ICSI embryo transfers, including the transfer of frozen and thawed embryos originating from those fresh cycles, and which did not result in a pregnancy or as having had at least one fresh IVF or ICSI transfer and at least two frozen embryo transfers with embryos originating from that fresh cycle which did not result in a pregnancy. The study was performed at the laboratory sites of three tertiary referral hospitals and two university medical centres in the Netherlands. MAIN RESULTS AND THE ROLE OF CHANCE The cumulative live birth rate per started cycle, including the transfer of fresh and subsequent frozen/thawed embryos if applicable, resulted in 77 live births in the assisted hatching group (n = 297, 25.9%) and 68 live births in the control group (n = 295, 23.1%). This proved to be statistically not significantly different (relative risk: 1.125, 95% CI: 0.847 to 1.494, P  = 0.416). LIMITATIONS, REASONS FOR CAUTION There was a small cohort of subfertile couples that after not achieving an ongoing pregnancy, still had cryopreserved embryos in storage at the endpoint of the trial, i.e. 1 year after the last randomization. It cannot be excluded that the future transfer of these frozen/thawed embryos increases the cumulative live birth rate in either or both study arms. Next, at the start of this study, there was no international consensus on the definition of repeated implantation failure. Therefore, it cannot be excluded that assisted hatching might be effective in higher order repeated implantation failures. WIDER IMPLICATIONS OF THE FINDINGS This study demonstrated no evidence of a statistically significant effect for assisted hatching by increasing live birth rates in subfertile couples with repeated implantation failure, i.e. the couples which, based on meta-analyses, are suggested to benefit most from assisted hatching. It is therefore suggested that assisted hatching should only be offered if information on the absence of evidence of effect is provided, at no extra costs and preferably only in the setting of a clinical trial taking cost-effectiveness into account. STUDY FUNDING/COMPETING INTEREST(S) None. TRIAL REGISTRATION NUMBER Netherlands Trial Register (NTR 3387, NL 3235, https://www.clinicaltrialregister.nl/nl/trial/26138). TRIAL REGISTRATION DATE 6 April 2012 DATE OF FIRST PATIENT'S ENROLMENT 28 November 2012 [ABSTRACT FROM AUTHOR]

At present, the problem of increasing the effectiveness of programs of assisted reproductive technologies and successful infertility treatment is still relevant. Assisted hatching used in the devitrificated embryo transfer facilitates the exit of the embryo from the pellucide zone. Yet the clinical efficacy of assisted hatching is relevant and debatable. There are no clear indications for the use of this technology, and no groups of patients have been identified.The aim of the study. To assess the effectiveness of laser hatching in the frozenthawed embryo transfer programs in patients with tuboperitoneal infertility.Materials and methods. We examined 300 women with tuboperitoneal infertility who had their embryos frozen for transfer. Inclusion criteria: age from 18 to 35 years; tuboperitoneal infertility; embryos cryopreserved for transfer. Exclusion criteria: age more than 36 years; other infertility factors. Women were divided into 2 groups: group 1 – women who had a frozen-thawed embryo transfer with preliminary laser hatching (n = 137); group 2 – control group (n = 163).Results. There were no differences between the groups in the mean age, body mass index and the age at menarche. According to the results of the embryological stage, there were also no differences in the number and quality of frozen embryos. The pregnancy rate in the group with preliminary laser hatching was 44.5 %, which is significantly higher than in the control group (42.3 %; р ≤ 0.001). We also found statistically significant differences in pregnancy outcomes: in the frequency of spontaneous miscarriages – 13.1 % and 20.2 % respectively (p ≤ 0.001), in the frequency of term deliveries – 30.7 % and 22.1 % respectively (p ≤ 0.001).Conclusion. In our study, the using laser hatching in women with tuboperitoneal infertility positively affected the embryos implantation in the cryopreservation protocols. Pregnancy and live birth rates are higher after using hatching technology, and the frequency of miscarriages up to 12 weeks is lower. This provide an opportunity to further study the effect of hatching on long-term outcomes, such as gestation course and childbirth.

Purpose: To determine if deep learning artificial intelligence algorithms can be used to accurately identify key morphologic landmarks on oocytes and cleavage stage embryo images for micromanipulation procedures such as intracytoplasmic sperm injection (ICSI) or assisted hatching (AH). Methods: Two convolutional neural network (CNN) models were trained, validated, and tested over three replicates to identify key morphologic landmarks used to guide embryologists when performing micromanipulation procedures. The first model (CNN-ICSI) was trained (n = 13,992), validated (n = 1920), and tested (n = 3900) to identify the optimal location for ICSI through polar body identification. The second model (CNN-AH) was trained (n = 13,908), validated (n = 1908), and tested (n = 3888) to identify the optimal location for AH on the zona pellucida that maximizes distance from healthy blastomeres. Results: The CNN-ICSI model accurately identified the polar body and corresponding optimal ICSI location with 98.9% accuracy (95% CI 98.5–99.2%) with a receiver operator characteristic (ROC) with micro and macro area under the curves (AUC) of 1. The CNN-AH model accurately identified the optimal AH location with 99.41% accuracy (95% CI 99.11–99.62%) with a ROC with micro and macro AUCs of 1. Conclusion: Deep CNN models demonstrate powerful potential in accurately identifying key landmarks on oocytes and cleavage stage embryos for micromanipulation. These findings are novel, essential stepping stones in the automation of micromanipulation procedures. [ABSTRACT FROM AUTHOR]

In recent years, the transfer of more than one embryo has become less frequent to diminish multiple pregnancies. Even so, there is still a risk of one embryo splitting into two or even three. This report presents the case of a triamniotic monochorionic gestation in a 35-year-old woman, obtained after the transfer of a single day 5 embryo that had been previously hatched with a laser and subsequently transferred in a fresh IVF cycle. The morphokinetics of this embryo as well as another eight that produced monozygotic twins were compared with nine embryos that achieved singleton gestations. An artificial intelligence (AI) system was used to perform this analysis objectively. Embryo divisions leading to multiple gestations were slower across all analysed parameters. This was most evident in the time taken to reach the 5-cell stage (t5) (48.74 ± 3.21 versus 44.69 ± 5.61 h) and the morula stage (tM) (85.08 ± 10.00 versus 78.13 ± 5.35 h). Moreover, blastocyst diameter (161.80 ± 26.50 versus 179.10 ± 25.88 μm) and area (21 684 ± 7267.4 versus 26 516 ± 7254.8 μm2) were smaller in these embryos, but the differences did not reach statistical significance. This is the first report, to our knowledge, to use AI to analyse and compare morphokinetic parameters between singleton pregnancies and a group of embryos that produced twin and triplet pregnancies., (© The Author(s) 2025. Published by Oxford University Press on behalf of European Society of Human Reproduction and Embryology. All rights reserved. For permissions, please email: journals.permissions@oup.com.)

At present, there is no standardised protocol for assisted hatching (AH) and the field is beset with contradictory data. We hypothesised that such contradiction may be related to inconsistencies in clinical practice. This study aimed to investigate the application, preferences, and variations of AH in current clinical practice prior to embryo transfer (AHpET) and biopsy (AHpBP). An online voluntary survey, consisted of 25 questions regarding different aspects of AH, was circulated amongst different fertility centres via newsletters between October 2019 and March 2020. One-hundred twenty-nine different fertility centres participated in the survey. AHpBP was widely used (90.6% [48/53]) amongst these centres, especially for trophectoderm biopsy (92.2% [47/51]). In contrast, only 64.6% (73/113) of centres administrated AHpET; the application of AHpET was even lower in UK-based centres (36.6% [15/41]). Although laser pulses have become the predominant technique for AH, significant variation existed in the precise strategy. Zona pellucida (ZP) drilling was the main method for AHpBP, whilst both ZP drilling and ZP thinning were applied equally for AHpET. Furthermore, the ZP manipulation varied widely with regards to the size of the ZP opening and the extension of ZP thinning. This is the first representative survey relating to the current practice of AH. Laser-assisted AH is used extensively, especially for AHpBP. However, there is significant disparity in clinical practice across different centres. Future research should aim to create a standardised protocol for AH to help reduce the evident variation in clinical practice and investigate the true value of AH. [ABSTRACT FROM AUTHOR]

Purpose: To create a Choosing Wisely Canada list of the top 5 diagnostic and therapeutic interventions that should be questioned in Reproductive Endocrinology and Infertility in Canada. Methods: The Canadian Fertility and Andrology Society (CFAS) National Working Group developed an initial list of recommendations of diagnostic and therapeutic interventions that are commonly used, but are not supported by evidence, and could expose patients to unnecessary harm. These were chosen based on their prevalence, cost, potential for harm, and quality of supporting evidence. A modified Delphi consensus was used over 5 rounds to generate ideas, review supporting evidence, assess clinical relevance, estimate recommendation impact and narrow the recommendations list to 5 items. Results: Fifty unique ideas were first proposed by the working group, and after 5 rounds including a survey of Canadian Fertility and Andrology Society (CFAS) members, the final list of recommendations was created, including topics related to unnecessary investigations and interventions for patients with infertility and recurrent pregnancy loss, and those undergoing IVF. In this article, we describe not only the Delphi process used to determine the list, but also provide a summary of the evidence behind each of the final recommendations. Conclusions: The list of five recommendations highlights opportunities to initiate conversations between clinicians and patients about the risks, benefits, harms and costs of unnecessary fertility treatments and procedures in a Canadian context. [ABSTRACT FROM AUTHOR]

Abstract Objective This study aims to determine the impact of assisted hatching (AH) on pregnancy outcomes in vitrified-warmed blastocyst transfers, and evaluate if embryo expansion or morphology influences outcomes. Methods A retrospective cohort study was performed including vitrified-warmed blastocyst transfers at our clinic between 2013 and 2017. Of the 2165 embryo transfers, 1986 underwent laser AH and 179 were non-assisted hatched (NAH). The primary outcome was live birth. Secondary outcomes included conception, implantation, clinical pregnancy, clinical pregnancy loss, and monozygotic twinning (MZT). Results AH and NAH groups had similar rates of conception (38.7% vs 42.1%), implantation (26.2% vs 27.3%), clinical pregnancy (29.1% vs 30.3%), clinical pregnancy loss (24.0% vs 17.8%), live birth (19.9% vs 20.5%), and MZT (2.08% vs 2.86%). Five pairs of dichorionic/diamniotic twins resulted from single embryo transfers. AH of embryos with expansion grades ≤3 was associated with lower rates of conception (32.5% vs 44.3%%, p

Abstract Background Recently, the Japan Society of Obstetrics and Gynecology initiated a clinical study of preimplantation genetic test for aneuploidy. There will be a great need for a standardized embryo biopsy technique in Japan. However, the gold standard trophectoderm (TE) biopsy procedure has not been established, and this review outlines the clinical use of TE biopsy. Methods Based on literature, the method and associated techniques for TE biopsy, a dissection method of TE cells from blastocysts, were investigated. Main findings Two TE biopsy methods are used, namely assisted hatching (herniating) and non‐assisted hatching (direct suction); however, it is not clear which of these methods is superior. It is critical to understand whether the flicking or pulling method is beneficial. Conclusion Non‐assisted hatching biopsy method may cause blastocyst collapse with a higher probability, and it may extend the biopsy time. The biopsy procedure should be performed within 3 minutes, and thus direct TE suction may have greater disadvantages. It is a fact that pulling method of TE dissection with laser pulse is simple; however, excess laser shots may induce a higher frequency of mosaicism. It is important to understand that each technique of TE biopsy has benefits and disadvantages.

In the last decades, to enhance success rates in assisted reproductive technology (ART) cycles, scientists have continually tried to optimize embryo culture and selection to increase clinical outcomes. In this scenario, the application of laser technology has increased considerably worldwide and is currently applied across ART in several ways: for assisted hatching (AH) or thinning of the zona pellucida (ZP), embryo biopsy, to immobilize and select the sperm during intracytoplasmic sperm injection, as well as to induce artificial blastocyst shrinkage before cryopreservation. Laser-AH has been suggested as a procedure to improve embryo implantation: the concept is that drilling holes through or thinning of the ZP could improve the hatching process and implantation. The artificial disruption of the ZP can be performed by different approaches: mechanically, chemically and with the laser, which is one of the most favourable and easy methods to remove part of the ZP and to augment the possibilities of implantation in patients defined as having a poor prognosis of success, or when the ZP is too thick. However, in the current literature, there is not sufficient evidence about the potential risk or impairment that laser utilization might induce on embryo development; therefore, the main aim of the current review is to provide an overview of the existing knowledge on the ZP and the mechanisms of manipulating it to improve the effectiveness of ART. Also, it emphasizes the positive aspect of laser application as a powerful tool that might increase the chance of pregnancy for infertile couples undergoing ART cycles., Competing Interests: Declaration of Competing Interest The manuscript has been seen and approved by all authors and is not under active consideration for publication. Finally, the authors declare that they do not have any commercial or associative interest that represents a conflict of interest in connection with the work submitted. SF is also an employee of CooperSurgical Fertility Solutions., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)

Purpose: To ascertain if assisted hatching (AH) increases the risk of placenta-associated diseases and perinatal outcomes after frozen–thawed cleavage-stage embryo transfer. Methods: We retrospectively evaluated 924 women who conceived with frozen–thawed cleavage-stage embryos transfer with (n = 390) or without (n = 534) laser-AH between 2013 and 2015. Data were obtained from the database on in vitro fertilization (IVF) patients in Shanghai First Maternity and Infant Hospital. We assessed neonatal (preterm birth, low birthweight, fetal macrosomia, stillbirth) and obstetric (miscarriage, ectopic pregnancy, post-term pregnancy, gestational diabetes (GDM), preeclampsia, intrahepatic cholestasis (ICP), placenta previa, placental abruption, premature rupture of membranes) outcomes. Results: In twins, the median birthweight was lower in the AH group than that in the control group, and the prevalence of low birthweight (< 2500 g) was significantly higher in the AH group; after adjusting for maternal age, body mass index, mode of fertilization, and parity, no significant difference was found. In twins, no significant difference was detected in the prevalence of stillbirth or preterm pregnancy. In singleton births, there was no significant difference in the prevalence of low birthweight, macrosomia, preterm pregnancy or post-term pregnancy between the two groups. In singletons and twins, there were no significant differences in the prevalence of miscarriage, ectopic pregnancy, preeclampsia, GDM, ICP, or placenta abruption between the two groups. Conclusions: AH is a relatively safe method and our study provides important information for using this method in carefully selected patients. [ABSTRACT FROM AUTHOR]

For in vitro produced embryos generated from in vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI) procedure, the intra- and extra-environmental factors during in vitro culture have significant impact on latter embryo development and fetus growth. Assisted hatching (AH), an effective approach to facilitate hatchability for in vitro generated embryos, is an essential step for successful embryo implantation in the uterus. However, regarding the different AH methods reported in clinical practice, it is still unknown whether zona pellucida (ZP) broken is based on AH applied in diverse stages of embryos affect implantation and fetal development. Here, piezo-mediated AH treatments were classified into four categories: (1) drilling one small hole (SH) with a diameter of 10 μm on ZP (SH); (2) drilling one large hole (LH) with a diameter of 40 μm on ZP (LH); (3) made a small area with diameter of 40-μm thinner on ZP [small area thinner (ST)]; (4) made a large area with a diameter of 80-μm thinner [large area thinner (LT)]. These four AH treatments were applied in different stage embryos including two-cell, four-cell, and morula. The most efficient AH approach was chosen according to the final hatch rate at 120 h after fertilization. We found that the approach of SH applied in morula-stage embryos obtained the highest hatch rate. To further investigate if this treatment has any side effect on later development after embryo transfer, we evaluated embryo implantation, gestational period, litter size, and growth. Our results showed that SH applied in morula-stage embryos could facilitate the implantation process and increase litter size. Meanwhile, this approach had no side effect on birth weight, growth, or gender ratio in the offspring. We conclude that drilling a SH on ZP in morula-stage embryos is an effective and reliable AH approach for in vitro cultured embryos in rodent. And this approach is worth further investigating in human-assisted reproductive technology.

Blastocysts hatch from the zona pellucida (ZP) to enable implantation into the uterine endometrial epithelium, but little is known regarding the effect of hatching sites on pregnancy outcomes. Murine hatching embryos were categorized into five groups based on initial trophectoderm projection (TEP)/ZP position corresponding to the inner cell mass center. In blastocysts (3.5 dpc) post‐12 hours in vitro culture, TEP rates of A‐site (44.4%) and B‐site (38.6%) embryos were higher than those of C‐site (12.5%) and D‐site (3.1%) embryos, while the O‐site (1.4%) was the lowest (P < .05). Post‐ET A‐site (55.6%) and B‐site (65.6%) birth rates were higher than those of C‐site embryos (21.3%) and controls (P < .05). Furthermore, live birth rate of B‐site embryos remained higher than C‐site embryos (68.8% vs 31.3%; P < .05) when both were transferred into the same recipients. Different TEP site blastocysts exhibited different implantation competences: the implantation rate of C‐site embryos was lower than that of both A‐ and B‐site groups (67.7% vs 84.3% and 83.2%, respectively; P < .05) at 2 days post‐ET. C‐site embryos also had a distinctly higher ratio of developmental defects (47.5%) than A‐ and B‐site embryos (22.5% and 14.6%, respectively), with implantation failure mainly associated with poor birth rate, a finding corroborated by differential gene expression analysis such as LIF, LIFR, and S100a9. Surprisingly, acidified Tyrode's solution (AAH)‐treated B‐site blastocysts had a significantly increased birth rate (77.1%) than C‐site (55.3%) and controls (43.4%). Site specificity and differential gene expression during embryo hatching can be applied in ART screening. More importantly, assisted hatching by AAH is effective and feasible for improving pregnancy and term development, particularly at the B‐site, for humans and in animal husbandry. [ABSTRACT FROM AUTHOR]

Study Question: What is the prevalence and pattern of IVF add-on use in Australia?Summary Answer: Among women having IVF in the last 3 years, 82% had used one or more IVF add-on, most commonly acupuncture, preimplantation genetic testing for aneuploidy and Chinese herbal medicine.What Is Known Already: IVF add-ons are procedures, techniques or medicines which may be considered nonessential to IVF, but usually used in attempts to improve the probability of conception and live birth. The use of IVF add-ons is believed to be widespread; however, there is little information about the prevalence and patterns of use in different settings.Study Design, Size, Duration: An online survey was distributed via social media to women in Australia who had undergone IVF since 2017. Women were excluded if they were gestational surrogates, used a surrogate, or underwent ovarian stimulation for oocyte donation or elective oocyte cryopreservation only. The survey was open from 21 June to 14 July 2020.Participants/materials, Setting, Methods: Survey questions included demographics, IVF and medical history, and use of IVF add-ons including details of the type of add-on, costs and information sources used. Participants were also asked about the relative importance of evidence regarding safety and effectiveness, factors considered in decision-making and decision regret.Main Results and the Role Of Chance: A total of 1590 eligible responses were analysed. Overall, 82% of women had used one or more add-ons and these usually incurred an additional cost (72%). Around half (54%) had learned about add-ons from their fertility specialist, and most reported that the decision to use add-ons was equally shared with the specialist. Women placed a high level of importance on scientific evidence for safety and efficacy, and half (49%) assumed that add-ons were known to be safe. Most women experienced some regret at the decision to use IVF add-ons (66%), and this was more severe among women whose IVF was unsuccessful (83%) and who believed that the specialist had a larger contribution to the decision to use add-ons (75%).Limitations, Reasons For Caution: This retrospective survey relied on patient recall. Some aspects were particularly prone to bias such as contributions to decision-making. This approach to capturing IVF add-on use may yield different results to data collected directly from IVF clinics or from fertility specialists.Wider Implications Of the Findings: There is a very high prevalence of IVF add-on use in Australia which may be generalisable to other settings with similar models of IVF provision. Although women placed high importance on scientific evidence to support add-ons, most add-ons do not have robust evidence of safety and effectiveness. This suggests that IVF patients are not adequately informed about the risks and benefits of IVF add-ons, or are not aware of the paucity of evidence to support their use.Study Funding/competing Interest(s): This research was supported by a McKenzie Postdoctoral Fellowship Grant (University of Melbourne), a Department of Obstetrics and Gynaecology Innovation Grant (University of Melbourne) and an NHMRC Investigator Grant (APP1195189). A.P. declares that he provides fertility services at Melbourne IVF (part of Virtus Health). J.W. reports grants from Wellcome Trust, during the conduct of the study, and that publishing benefits his career. The remaining authors report no conflict of interest.Trial Registration Number: N/A. [ABSTRACT FROM AUTHOR]

In vitro fertilization (IVF) is associated with a higher incidence of monozygotic twin pregnancies, which are known to be burdened by a higher risk of main obstetric complications. The reasons behind this association are still unclear. In the present study, we therefore investigate the risk factors for monozygotic twinning in pregnancies achieved by IVF. We conducted a multicenter retrospective case-control study. All IVF cycles performed between 2014 and 2019 at the infertility units of two Italian academic institutes were retrospectively reviewed. Only pregnancies obtained with single embryo transfer were eligible. A total of 50 monozygotic twin pregnancies (cases) were identified and matched in a 1:5 ratio to 250 singleton pregnancies (controls) by study center and study period. Monozygotic twin pregnancies were diagnosed by ultrasound. Women experiencing miscarriage could be included provided that the pregnancy loss occurred after a definitive diagnosis of monozygotic twin pregnancy. Demographic, clinical, and embryological characteristics were retrieved from patients' charts. Overall, the incidence of monozygotic twin pregnancies was 1.2% (50 out of 4016 single embryo transfers). At univariate analyses, statistically significant differences emerged for BMI, peripheral levels of estradiol and progesterone at the time of hCG administration, total number of retrieved suitable oocytes, freezing-thawing cycles, and assisted hatching. After performing a multivariate logistic analysis, only assisted hatching remained significantly associated with monozygotic twinning (adjusted odds ratio 2.32, 95%CI 1.03–5.25). Blastomere separation during the passage through this artificial hole or interference with the signaling pathway within the embryo could be the mechanisms involved. [ABSTRACT FROM AUTHOR]

Assisted hatching (AH) involves artificial disruption of the zona pellucida prior to embryo transfer. The purpose of this study is to examine the safety of AH technique and its effect on obstetrical, perinatal and neonatal outcomes and risk of developmental delay. This is a retrospective cohort of ART cycles using laser AH technique. The study group consisted of 120 cases of AH cycles resulting in singleton pregnancies and live births compared with 113 control cases. A current phone questionnaire was conducted to assess child development in the first year of life. AH was not associated with increased risk for all obstetrical and perinatal outcomes examined including PPROM, gestational diabetes, hypertensive diseases of pregnancy, delivery by cesarean section, gestational age at delivery, low birth weight (LBW), preterm birth and neonatal Apgar score (p>.05). No significant differences were observed between AH and control group in rates and risk of congenital malformations (5.8 vs. 4.4%, respectively, OR 1.33, 95% CI 0.41–4.34) and developmental delay (19.2 vs. 12.8%, respectively, OR 1.62, 95% CI 0.74–3.52). AH did not increase the risk of obstetrical and neonatal complications in singleton pregnancies, including congenital malformations and child developmental delay. AH may therefore be considered a safe method of ART. [ABSTRACT FROM AUTHOR]

How are IVF clinic websites advertising three common IVF add-ons: assisted hatching, time-lapse embryo imaging and preimplantation genetic testing for aneuploidies (PGT-A)? The Human Fertilisation and Embryology Authority 'Choose a fertility clinic' website service was used to identify IVF clinics and their websites. Assisted hatching, time-lapse embryo imaging and PGT-A were examined to determine which websites advertised them, what price they charged and what claims they made in relation to the add-ons. Eighty-seven eligible clinics were identified, with 72 unique websites; 37 (43%) clinics were part of one of nine groups of IVF clinics, of sizes ranging from two to eight clinics in the UK. Time-lapse imaging (TLI) was the most frequently advertised of the three add-ons (67% of clinics), followed by PGT-A (47%) and assisted hatching (28%). Very few websites stated that the effectiveness of the add-on was in doubt or unclear (four, two and one websites for TLI, PGT-A and assisted hatching, respectively), and none raised the possibility that an add-on might have negative effects. Claims of efficacy were often based on upstream outcomes (e.g. implantation, pregnancy). Some claims that PGT-A and TLI improved live birth rates were found. There was substantial variation in pricing. IVF clinic websites provide valuable information for patients seeking fertility treatment so it is key that the information is accurate and complete. There is a need for transparent information on interventions, including uncertainties and risks, to be made available by IVF clinics to support well-informed treatment decisions. The selected add-ons are widely advertised, and there is wide variation in pricing. [ABSTRACT FROM AUTHOR]

Objective: This study aims to determine the impact of assisted hatching (AH) on pregnancy outcomes in vitrified-warmed blastocyst transfers, and evaluate if embryo expansion or morphology influences outcomes. Methods: A retrospective cohort study was performed including vitrified-warmed blastocyst transfers at our clinic between 2013 and 2017. Of the 2165 embryo transfers, 1986 underwent laser AH and 179 were non-assisted hatched (NAH). The primary outcome was live birth. Secondary outcomes included conception, implantation, clinical pregnancy, clinical pregnancy loss, and monozygotic twinning (MZT). Results: AH and NAH groups had similar rates of conception (38.7% vs 42.1%), implantation (26.2% vs 27.3%), clinical pregnancy (29.1% vs 30.3%), clinical pregnancy loss (24.0% vs 17.8%), live birth (19.9% vs 20.5%), and MZT (2.08% vs 2.86%). Five pairs of dichorionic/diamniotic twins resulted from single embryo transfers. AH of embryos with expansion grades ≤3 was associated with lower rates of conception (32.5% vs 44.3%%, p < 0.05) and clinical pregnancy (24.0% vs 32.8%, p < 0.05). Conclusion: AH prior to transfer of vitrified-warmed blastocysts was not associated with improved pregnancy outcomes. The identification of dichorionic/diamniotic twins from single blastocyst transfers challenges the previously held notion that dichorionic/diamniotic MZTs can only occur from division prior to the blastocyst stage. Prospective studies are needed to validate the novel finding of lower rates of conception and clinical pregnancy after AH in embryos with lower expansion grade. [ABSTRACT FROM AUTHOR]

Objectives: To investigate the effects of laser assisted hatching (LAHA) implantation rates, clinical pregnancies, and live births of the patients enrolled in a fresh in vitro fertilization and intracytoplasmic sperm injection-embryo transfer (IVF/ICSE-ET) program. Material and Methods: A total of 315 patients who underwent at least two unsuccessful ETs or had a baseline follicle-stimulating hormone (FSH) level of ≥10 mIU/mL and who underwent IVF/ICSE-ET at IVF Center. The patients were divided into two groups: patient group (n=100) who underwent LAHA and control group (n=215) who did not. The beta human chorionic gonadotropin (βhCG) positivity, clinical pregnancies, and live births of both groups were compared. Results: There was no significant difference in the clinical pregnancy and implantation rates between the groups including those with an advanced maternal age or recurrent implantation failure. In the patients with elevated FSH levels (FSH ≥10 mIU/mL), these rates were significantly lower in the study group, compared to the control group. Conclusion: Our study results show that laser assisted hatching does not improve the biochemical, clinical, and take home baby rates in IVF / ICSI – ET patients. [ABSTRACT FROM AUTHOR]

Background: Recently, the Japan Society of Obstetrics and Gynecology initiated a clinical study of preimplantation genetic test for aneuploidy. There will be a great need for a standardized embryo biopsy technique in Japan. However, the gold standard trophectoderm (TE) biopsy procedure has not been established, and this review outlines the clinical use of TE biopsy. Methods: Based on literature, the method and associated techniques for TE biopsy, a dissection method of TE cells from blastocysts, were investigated. Main findings: Two TE biopsy methods are used, namely assisted hatching (herniating) and non‐assisted hatching (direct suction); however, it is not clear which of these methods is superior. It is critical to understand whether the flicking or pulling method is beneficial. Conclusion: Non‐assisted hatching biopsy method may cause blastocyst collapse with a higher probability, and it may extend the biopsy time. The biopsy procedure should be performed within 3 minutes, and thus direct TE suction may have greater disadvantages. It is a fact that pulling method of TE dissection with laser pulse is simple; however, excess laser shots may induce a higher frequency of mosaicism. It is important to understand that each technique of TE biopsy has benefits and disadvantages. [ABSTRACT FROM AUTHOR]

Objective: To compare two different blastocyst biopsy protocols.Design: Retrospective single-center cohort study.Settings: Private in vitro fertilization center.Patient(s): The study included 1,670 frozen-thawed embryo transfers (FETs) with preimplantation genetic testing for aneuploidy (PGT-A).Intervention: None.Main Outcome Measure(s): Survival rate (SR) after thawing, clinical pregnancy rate (CPR), ongoing implantation rate (IR), and live birth rate (LBR).Result(s): Eight hundred thirty-five FETs with PGT-A cycles including only embryos biopsied in the sequential blastocyst hatching and biopsy protocol paired with the ablation of one-fourth of the zona pellucida (ZP) were matched with 835 FETs with PGT-A cycles including only embryos biopsied in the day 3 prehatching protocol by female age (±1 year), number of embryos transferred, use of gestational carrier or egg donor, and day of blastocyst transfer. Only FETs with euploid blastocysts graded no lower than 4BB were included, and cycles with fewer than five oocytes were excluded. SR after thawing, CPR, ongoing IR, and LBR were significantly higher in the FET cycles with the embryos biopsied in the sequential hatching and biopsy protocol. Four cases of monozygotic twin pregnancies were reported with the day 3 prehatching protocol and none with the sequential hatching and biopsy protocol.Conclusion(s): Our results show, for the first time, that using different blastocyst biopsy protocols can affect clinical outcomes. Because the study was retrospective, our findings should be validated in a prospective trial. [ABSTRACT FROM AUTHOR]

Purpose: To assess the effect of assisted hatching (AH) on live birth rate (LBR) in first cycle, fresh in vitro fertilization (IVF) in good and poor prognosis patients. Methods: Retrospective cohort using cycles reported to the Society for Assisted Reproductive Technology Clinic Outcomes Reporting System. Live birth rate was compared in women who underwent first cycle, autologous, fresh IVF cycles with (n = 48,858) and without (n = 103,413) AH from 2007 to 2015. Results: The propensity-weighted LBR was 39.2% with AH versus 43.9% without AH in all patients. The rate difference (RD) with AH was − 4.7% ([CI − 0.053, − 0.040], P < 0.001) with the calculated number needed to harm being 22. AH affected live birth in both good prognosis and poor prognosis patients. The propensity-weighted monozygotic twinning (MZT) rate was 2.3% in patients treated with AH as compared to 1.2% patients that did not receive AH. The RD with AH on MZT in fresh, first IVF cycles was 1.1% ([0.008, 0.014], P < 0.001). Conclusion: AH may affect LBR across all patients and in poor prognosis patients in fresh IVF cycles. Caution should be exercised when applying this technology. More prospective research is needed. [ABSTRACT FROM AUTHOR]

Does complete mechanical removal of the zona pellucida modify the outcome of transfer of vitrified–warmed human blastocysts? In a prospective randomized controlled study, 419 couples were allocated to either zona pellucida-free (n = 209) or zona intact (n = 210) vitrified–warmed embryo transfer. Main outcome measures included clinical pregnancy, implantation and ongoing pregnancy rates. Transfer of zona pellucida-free blastocysts resulted in clinical pregnancy, implantation and ongoing pregnancy rates (35,9%, 33,9% and 32,1%, respectively), similar to those achieved with zona intact control embryos (39%, 36,4% and 33,1%, respectively). Total mechanical removal of the zona pellucida did not affect the tested parameters of clinical outcomes. [ABSTRACT FROM AUTHOR]

Objective: Assisted hatching (AH) was introduced 3 decades ago as an adjunct method to in vitro fertilization (IVF) and embryo transfer (ET) to improve embryo implantation rate. Limited data are available on the effect of AH on live birth rate (LBR) in advanced maternal age. The objective of this study is to investigate the effect of AH on LBR in women aged 40 years and older. Materials and Methods: A retrospective study conducted at a single academic reproductive center. Women aged ≥40 years, who were undergoing their first IVF cycle were included. Laser-assisted hatching was the method used for AH and single or double embryos were transferred. Embryo transfer was performed at the cleavage or blastocyst stage. Separate analysis was performed on each ET stage. Live birth rate was the primary outcome. Results: A total of 892 patients were included. Of these, 681 women underwent cleavage ET and 211 underwent blastocyst ET. The clinical pregnancy rate in the entire group was 15.3% and the LBR was 10.2%. Baseline and cycle parameters between the AH group and the control group were comparable. Assisted hatching in the cleavage stage was associated with lower clinical pregnancy rate (odds ratio [OR], 0.52; confidence interval [CI], 0.31-0.86; P =.012) and lower LBR (OR, 0.36; CI, 0.19-0.68; P =.001). Assisted hatching did not have any effect on outcomes in blastocyst ET. Conclusion: Assisted hatching does not improve the reproductive outcomes in advanced maternal age. Performing routine AH for the sole indication of advanced maternal age is not clinically justified. [ABSTRACT FROM AUTHOR]

Abstract To improve success rates, assisted reproductive technology (ART) procedures continually undergo optimization and enhancement such that the best quality gametes and embryos can be identified and manipulated, thus improving clinical outcomes. Laser technology is now being applied across ART to reduce procedure times and increase the consistency and reproducibility of traditional ART techniques such as assisted hatching, embryo biopsy, intracytoplasmic sperm injection cryopreservation and sperm immobilization/selection. This review examines the current status of cutting-edge laser-assisted reproductive technologies, investigates experimental techniques that are increasingly being applied clinically. It highlights the benefits of lasers as a powerful technology at the forefront of both diagnostic and therapeutic treatments for general subfertility and male-factor infertility. However, it is important to note that although lasers are becoming increasingly commonplace in ART units, there is comparatively little information in the existing literature pertaining to the potential negative effects that laser application might have on the developing human embryo, thus creating the need for further investigative research. [ABSTRACT FROM AUTHOR]

Objective: systematic review to determine the role of assisted hatching in the IVF cycles. Materials and methods. We searched the MEDLINE base (2005 to February 2016) and included all articles related to the question. Results. Possible mechanisms and efficiency of assisted hatching in embryo implantation are described below as well as possible factors that influence the efficiency of spontaneous hatching. Conclusions. The included trials provided insufficient data to investigate the role of different types of the assisted hatching in clinical pregnancy rate, live birth rate and development of multiple gestations.

PurposeA noncontact holmium:yttrium scandium gallium garnet (Ho:YSGG) laser system has been designed and tested for the micromanipulation of mammalian embryos. The purpose of this preliminary investigation was to determine the effectiveness of this laser for assisted hatching and evaluate its impact on embryo viability. The Ho:YSGG system, utilizing 250-microsecond pulses at a wavelength of 2.1 microns and 4 Hz, was used to remove a portion of the zona pellucida (ZP) of two- to four-cell FVB mouse embryos.ResultsIn the first experiment there was no difference in blastocyst production or hatching rates following laser or conventional assisted hatching (LAH or AH, respectively) in contrast to control embryos cultured in a 5% CO2 humidified air incubator at 37 degrees C. In the second experiment a blastocyst antihatching culture model was employed and LAH-treated embryos were cultured in a serum-free HTF medium (HTF-o). Blastocyst formation was not influenced by LAH treatment and hatching was increased (P < 0.01) from 4 to 60% compared to HTF-o control group.ConclusionsThese preliminary data demonstrate the utility and nontoxic properties of the Ho:YSGG laser system for quick and precise ZP drilling.

This case report examines the difficulties faced by a couple with 11 years of primary infertility. Based on the diagnostic evaluation, it was determined that the male was a necrozoospermia patient, while the female had unilateral cornual blockage and polycystic ovarian syndrome (PCOS) with diabetes mellitus (DM) symptoms identified. A comprehensive approach was used in the treatment for the female patient, which included a gonadotropin-releasing hormone (GnRH) short antagonist protocol, a GnRH agonist (GnRHa) trigger, assisted hatching (AH), and the use of the hypo-osmotic swelling test (HOST) to gauge the viability of the sperm. The successful outcome, as evidenced by the increasing levels of beta-human chorionic gonadotropin (β-hCG) and a successful embryo transfer, highlights the effectiveness of a customized and multifaceted approach in managing intricate infertility problems. This instance offers insightful information about the way modern reproductive technologies can be successfully integrated with specialized treatment plans to achieve successful outcomes in difficult cases of infertility., Competing Interests: The authors have declared that no competing interests exist., (Copyright © 2024, Khemani et al.)

Study Question: What is the prevalence of multiple pregnancy with zygotic splitting after single embryo transfer (SET)?Summary Answer: The prevalence of multiple pregnancy with zygotic splitting after SET was 1.36%.What Is Known Already: In 2008, the Japan Society of Obstetrics and Gynaecology (JSOG) recommended the adoption of SET to reduce multiple births. Since then, to improve the clinical pregnancy rate, elective SET using blastocyst transfer and frozen-warmed ET has increased. Blastocyst culture and zona pellucida manipulation, including ICSI and AH, have been widely reported as risk factors for monozygotic twinning. However, all these studies may have included cases with dizygotic pregnancies produced by a transferred embryo and a spontaneous conception.Study Design, Size, Duration: A retrospective observational study was performed, based on 937 848 SET cycles in registered ART data from the JSOG between 2007 and 2014. The study was approved by the Registration and Research Subcommittee of the JSOG and Juntendo University Ethics Committee.Participants/materials, Setting, Methods: To identify possible factors affecting the prevalence of zygotic splitting, we identified pregnancies, in which the number of foetuses exceeded the number of gestational sacs (GSs), to restrict our analysis to 'true' zygotic splitting. Multiple logistic regression analysis was performed using singleton pregnancy after SET, as control. P < 0.05 was considered statistically significant.Main Results and the Role Of Chance: Fresh and frozen-warmed SET produced 276 934 clinical pregnancies (29.5%/SET), including 4310 twins (1.56% of pregnancies) and 109 triplets (0.04% of pregnancies). Based on sex analysis of dichorionic twins after SET, the prevalence of multiple pregnancy with zygotic splitting was 1.36%. Statistical analysis revealed that compared to singleton pregnancies zygotic splitting pregnancies were associated with frozen-warmed ET cycles (odds ratio [OR] = 1.34; 95% CI: 1.16-1.55), blastocyst culture (OR = 1.79; 95% CI: 1.54-2.09) or AH (OR = 1.21; 95% CI: 1.08-1.35). In fresh ET cycles, the prevalence rate of zygotic splitting pregnancy after single blastocyst transfer was significantly higher than that after SET cycles with cleavage embryos (OR = 2.20; 95% CI: 1.83-2.66). However, no significant difference in ovarian stimulation and fertilization methods was recognized.Limitations, Reasons For Caution: In the current Japanese ART registry system, data regarding frozen-warmed ET do not include information about ovarian stimulation and fertilization methods. Registration for AH only began in 2010. There is no way of validating if data submitted by clinics is correct.Wider Implications Of the Findings: Clinicians should consider whether to counsel couples about the small increase in the risk of zygotic splitting associated with some embryo manipulations.Study Funding/competing Interest(s): No external funds were used for the study. The authors have no competing interests to declare.Trial Registration Number: None. [ABSTRACT FROM AUTHOR]

Background: The incidence of monozygotic twins (MZT) after ART appears to be higher than the incidence after spontaneous conceptions contradicting the aim of ART to avoid multiple pregnancies because of the associated risks.Objective and Rationale: The aim was to study the frequency of MZT after IVF and ICSI and how it is influenced by the day of embryo transfer, maternal age, zona pellucida manipulation, controlled ovarian stimulation, stimulation protocol, culture media and embryo quality.Search Methods: Original studies and reviews were identified by searching the PubMed, Embase and Cochrane databases up to March 2017. The inclusion criterion was publications focusing on the five study questions related to MZT in our study. The exclusion criteria were articles that did not include blastocyst transfer, were on non-humans, were not published in peer-reviewed journals, and were based only on case studies. All of the articles were categorized according to the Oxford Centre for Evidence-based Medicine's 'Levels of Evidence', and quality and risk of bias assessment was performed with 'The Cochrane Collaboration's Risk of Bias Tools'. A meta-analysis was performed to study the impact of the day of embryo transfer on the MZT rate.Outcomes: The literature search resulted in a total of 42 articles, including 38 original studies, for analysis. The included original studies reported a MZT rate with blastocyst transfer from zero to 13.2%. Our meta-analysis found a higher frequency of MZT after blastocyst transfer compared with cleavage-stage embryos transfer: odds ratio = 2.18, 95% CI: 1.93-2.48 (fixed effect meta-analysis). A younger maternal age may increase the MZT rate, and recent studies regarding the use of zona pellucida manipulating techniques have disagreed with the previous suspicion of a higher MZT rate after the use of these methods. The extended culture to-blastocyst stage is a potential risk factor for MZT, but it is uncertain whether this phenomenon is due to the extended time, culture media or greater likelihood of younger oocytes to reach the blastocyst stage. An increased frequency of MZT following the GnRH-agonist suppression protocol has been suggested, as well as a decreased frequency of MZT with high gonadotrophin doses, which could reflect an age-related effect. Only limited literature has focused on the role of embryo morphology in the MZT rate, therefore, this issue remains unresolved.Wider Implications: We found blastocyst transfer to be a risk factor for MZT. Hence, the results of this meta-analysis may weaken the previously proposed view that greater experience with blastocyst transfer and improved culture media could decrease the high rate of MZT after blastocyst transfer. To minimize the rate of MZT and the associated complications, the mechanisms underlying blastocyst transfer and MZT pregnancy must be elucidated. [ABSTRACT FROM AUTHOR]

Objective: To identify the incidence and risk factors associated with IVF-conceived monozygotic twinning (MZT).Design: Retrospective study.Setting: Academic hospital.Patient(s): A total of 3,463 women with clinical pregnancies between January 2014 and February 2015 were analyzed.Intervention(s): None.Main Outcome Measure(s): The measures were the incidence of MZT based on the number of embryos that were replaced, type of insemination method (conventional IVF or intracytoplasmic sperm injection [ICSI]), with or without the use of assisted hatching (AH), and day of embryo transferred in fresh and frozen cycles.Result(s): Ninety-three women (2.69%) with MZT were observed. No statistically significant differences were observed in the cycle parameters of fresh or frozen cycles between MZT and other non-MZT pregnancies. Specific IVF procedures or techniques, such as the number of embryo replaced, zona pellucida manipulation (ICSI and AH), and freeze-thaw procedure, did not significantly increase the rate of MZT, except for the day of embryo transferred. Compared with day 3 transferred, day 4 and 5/6 transferred showed an increased probability of MZT (odds ratio [OR], 2.73; 95% confidence interval [CI], 1.16-6.42 for day 4 transferred and OR, 3.68; 95% CI, 2.29-5.93 for day 5/6 transferred).Conclusion(s): Extended culture (advanced embryo stage) in fresh and frozen cycles appeared to be associated with increased rates of MZT. The effect of the number of embryos transferred, ICSI and AH, and freeze-thaw procedures on the risk for MZT was not demonstrated. [ABSTRACT FROM AUTHOR]

Zona pellucida (ZP) manipulation, termed “assisted hatching” (AH), has been introduced in order to favor embryo hatching and ultimately improve assisted reproductive technology success but with poor proofs of safety and biological plausibility. We herein provide a systematic review of clinical outcomes following the application of different methods of ZP manipulation on fresh or frozen/thawed embryos at different developmental stages in different groups of patients. Out of the 69 papers that compared the clinical outcomes deriving from hatched versus non-hatched embryos, only 11 considered blastocysts while the rest referred to cleavage stage embryos. The ZP thinning of fresh embryos either by chemical or laser approach was shown to provide very limited benefit in terms of clinical outcomes. Better results were observed with procedures implying a higher degree of zona manipulation, including zona removal. Studies comparing the mechanical or chemical procedures to those laser-mediated consistently reported a superiority of the latter ones over the former. Literature is consistent for a benefit of ZP breaching in thawed blastocysts. This review provides the current knowledge on the AH procedure in order to improve its efficacy in the appropriate context. Embryologists might benefit from the approaches presented herein in order to improve Assisted Reproduction Technologies (ART) outcomes. [ABSTRACT FROM AUTHOR]

Objective: To evaluate the effect of assisted reproductive techniques on the incidence of monozygotic twins (MZT) and the associated pregnancy outcomes. Materials and methods: This was a retrospective study of all in vitro fertilization (IVF)/intracytoplasmic sperm injection (ICSI) cycles with MZT pregnancies in our center from January 2001 to December 2011. The diagnosis of MZT pregnancies with their respective placental configurations was based on the results of ultrasonographic examinations performed during either the first or second trimester. The treatment characteristics and outcomes of each IVF cycle were recorded and stored in a computer database. Results: A total of 17 cycles with MZT pregnancies were identified, resulting in an overall incidence of MZT of 1.3%. The incidence of MZT for women aged

Purpose: The purpose of this study is to examine the spectrum of infertility diagnoses and assisted reproductive technology (ART) treatments in relation to risk of preterm birth (PTB) in singletons. Methods: Population-based assisted reproductive technology surveillance data for 2000-2010 were linked with birth certificates from three states: Florida, Massachusetts, and Michigan, resulting in a sample of 4,370,361 non-ART and 28,430 ART-related singletons. Logistic regression models with robust variance estimators were used to compare PTB risk among singletons conceived with and without ART, the former grouped by parental infertility diagnoses and treatment modalities. Demographic and pregnancy factors were included in adjusted analyses. Results: ART was associated with increased PTB risk across all infertility diagnosis groups and treatment types: for conventional ART, adjusted relative risks ranged from 1.4 (95% CI 1.0, 1.9) for male infertility to 2.4 (95% CI 1.8, 3.3) for tubal ligation. Adding intra-cytoplasmic sperm injection and/or assisted hatching to conventional ART treatment did not alter associated PTB risks. Singletons conceived by mothers without infertility diagnosis and with donor semen had an increased PTB risk relative to non-ART singletons. Conclusions: PTB risk among ART singletons is increased within each treatment type and all underlying infertility diagnosis, including male infertility. Preterm birth in ART singletons may be attributed to parental infertility, ART treatments, or their combination. [ABSTRACT FROM AUTHOR]

Purpose: The aim of this study was to determine if zona pellucida thickness variation (ZPTV) is associated with implantation and if this relationship changes with use of assisted hatching (AH). Methods: Day 3 embryos from single or double embryo transfers (DETs) performed between 2014 and 2016 were included. ZPTV was assessed by examining photographs taken before transfer using an automated image processing platform to segment the zona pellucida (ZP) with an active contour technique. One hundred points were obtained of ZP thickness (ZPT) of each embryo to calculate ZPTV ([maximum ZPT-mean ZPT]/mean ZPT). Logistic regression was used to calculate the odds ratio (OR) and 95% confidence intervals (CI) of implantation by tertile of ZPTV. Maternal age and AH were adjusted for a priori . Other cycle and embryo characteristics were adjusted for if they altered the continuous effect estimate by >10%. Results: There was no statistically significant association between ZPTV and implantation across tertiles although embryos with greater ZPTV showed a trend of decreased implantation (Tertile 2 (T2) versus Tertile 1 (T1), OR = 0.80, CI = 0.50-1.28; Tertile 3 (T3) versus Tertile 1 (T3), OR = 0.75, CI = 0.47-1.20). While similar nonsignificant trends for the association between ZPTV and implantation were observed across tertiles after stratification of embryos hatched or not, embryos with the greatest ZPTV had slightly higher odds for implantation when AH was utilized (T3 vs. T1: with AH, OR = 0.89, CI = 0.49-1.62; without AH, OR = 0.61, 0.29-1.27). Conclusion: ZPTV was not associated with implantation after day 3 transfer. This finding did not vary by use of AH. [ABSTRACT FROM AUTHOR]

Objective: To assess the effect of assisted hatching (AH) on live-birth rates in a retrospective cohort of patients undergoing first-cycle, autologous frozen embryo transfer (FET).Design: Longitudinal cohort using cycles reported to the Society for Assisted Reproductive Technology Clinic Outcomes Reporting System between 2004 and 2013.Setting: Not applicable.Patient(s): Women who underwent first-cycle, autologous FET with (n = 70,738) and without (n = 80,795) AH reported from 2004 to 2013.Intervention(s): None.Main Outcome Measure(s): Live births.Result(s): Propensity matching was used to account for confounding covariates, and a logistic regression model was constructed to identify the predictors of live-birth rates in relationship to AH. In all first-cycle FETs, there was a slight but statistically significant decrease in the live-birth rate with AH compared with no AH (34.2% vs. 35.4%). In older patients and in the years 2012-2013 AH was associated with decreased live births. Live-birth rates and the number of AH cycles performed before FET vary by the geographic location of clinics.Conclusion(s): Assisted hatching slightly decreases the live-birth rate in first-cycle, autologous FET. Its use should be carefully considered, especially in patients 38 years old and older. Prospective, clinical studies are needed to improve our knowledge of the impact of AH. [ABSTRACT FROM AUTHOR]

Infertility, defined as the inability to conceive within 1 year of unprotected intercourse, affects an estimated 80 million individuals worldwide, or 10-15% of couples of reproductive age. Assisted reproductive technology includes all infertility treatments to achieve conception; in vitro fertilization is the process by which an oocyte is fertilized by semen outside the body; non-in vitro fertilization assisted reproductive technology treatments include ovulation induction, artificial insemination, and intrauterine insemination. Use of assisted reproductive technology has risen steadily in the United States during the past 2 decades due to several reasons, including childbearing at older maternal ages and increasing insurance coverage. The number of in vitro fertilization cycles in the United States has nearly doubled from 2000 through 2013 and currently 1.7% of all live births in the United States are the result of this technology. Since the birth of the first child from in vitro fertilization >35 years ago, >5 million babies have been born from in vitro fertilization, half within the past 6 years. It is estimated that 1% of singletons, 19% of twins, and 25% of triplet or higher multiples are due to in vitro fertilization, and 4%, 21%, and 52%, respectively, are due to non-in vitro fertilization assisted reproductive technology. Higher plurality at birth results in a >10-fold increase in the risks for prematurity and low birthweight in twins vs singletons (adjusted odds ratio, 11.84; 95% confidence interval, 10.56-13.27 and adjusted odds ratio, 10.68; 95% confidence interval, 9.45-12.08, respectively). The use of donor oocytes is associated with increased risks for pregnancy-induced hypertension (adjusted odds ratio, 1.43; 95% confidence interval, 1.14-1.78) and prematurity (adjusted odds ratio, 1.43; 95% confidence interval, 1.11-1.83). The use of thawed embryos is associated with higher risks for pregnancy-induced hypertension (adjusted odds ratio, 1.30; 95% confidence interval, 1.08-1.57) and large-for-gestation birthweight (adjusted odds ratio, 1.74; 95% confidence interval, 1.45-2.08). Among singletons, in vitro fertilization is associated with increased risk of severe maternal morbidity compared with fertile deliveries (vaginal: adjusted odds ratio, 2.27; 95% confidence interval, 1.78-2.88; cesarean: adjusted odds ratio, 1.67; 95% confidence interval, 1.40-1.98, respectively) and subfertile deliveries (vaginal: adjusted odds ratio, 1.97; 95% confidence interval, 1.30-3.00; cesarean: adjusted odds ratio, 1.75; 95% confidence interval, 1.30-2.35, respectively). Among twins, cesarean in vitro fertilization deliveries have significantly greater severe maternal morbidity compared to cesarean fertile deliveries (adjusted odds ratio, 1.48; 95% confidence interval, 1.14-1.93). Subfertility, with or without in vitro fertilization or non-in vitro fertilization infertility treatments to achieve a pregnancy, is associated with increased risks of adverse maternal and perinatal outcomes. The major risk from in vitro fertilization treatments of multiple births (and the associated excess of perinatal morbidity) has been reduced over time, with fewer and better-quality embryos being transferred. [ABSTRACT FROM AUTHOR]