The role of zygotic genome activation in genetic-related reproductive medicine: Technological perspective, religious and bioethical concerns, challenges and benefits

Zygotic Genome Activation (ZGA) is a crucial developmental milestone in early embryogenesis, marking the transition from maternal to embryonic control of development. This process, which varies in timing across species, involves the activation of the embryonic genome, paving the way for subsequent cell differentiation and organismal development. Recent advances in genomics and reproductive medicine have highlighted the potential of ZGA in the realm of genetic screening, providing a window into the genetic integrity of the developing embryo at its earliest stages. The intersection of ZGA and genetic screening primarily emerges in the context of preimplantation genetic diagnosis (PGD) and preimplantation genetic screening (PGS). These techniques, often employed during assisted reproductive technologies, aim to detect potential genetic abnormalities or chromosomal imbalances before embryo implantation. Given that ZGA represents the onset of embryonic gene expression, understanding its intricacies can significantly enhance the accuracy and predictive power of these screening processes. With the advent of next-generation sequencing and other high-throughput genomic techniques, detailed mapping of the transcriptomic changes during ZGA has become feasible. Such advancements have deepened our insights into the dynamics of early embryonic development and the onset of genetic disorders. As our knowledge in this realm expands, it promises to revolutionize our capabilities in detecting, understanding, and potentially rectifying genetic anomalies at the earliest stages of human life, thereby optimizing reproductive outcomes.

Where Does Life Begin? Discerning the Impact of Dobbs on Assisted Reproductive Technologies

This article explores the impact of Dobbs on access to assisted reproductive technologies. Clinical aspects of IVF, including embryo discard and cryopreservation, preimplantation genetic testing, and selective reduction of multiple pregnancy are potentially jeopardized by a new legal landscape that protects embryos over the interest of infertility patients.

Clinical and molecular characterization of patients affected by Beckwith-Wiedemann spectrum conceived through assisted reproduction techniques

The prevalence of Beckwith–Wiedemann spectrum (BWSp) is tenfold increased in children conceived through assisted reproductive techniques (ART). More than 90% of ART‐BWSp patients reported so far display imprinting center 2 loss‐of‐methylations (IC2‐LoM), versus 50% of naturally conceived BWSp patients. We describe a cohort of 74 ART‐BWSp patients comparing their features with a cohort of naturally conceived BWSp patients, with the ART‐BWSp patients previously described in literature, and with the general population of children born from ART. We found that the distribution of UPD(11)pat was not significantly different in ART and naturally conceived patients. We observed 68.9% of IC2‐LoM and 16.2% of mosaic UPD(11)pat in our ART cohort, that strongly differ from the figure reported in other cohorts so far. Since UPD(11)pat likely results from post‐fertilization recombination events, our findings allows to hypothesize that more complex molecular mechanisms, besides methylation disturbances, may underlie BWSp increased risk in ART pregnancies. Moreover, comparing the clinical features of ART and non‐ART BWSp patients, we found that ART‐BWSp patients might have a milder phenotype. Finally, our data show a progressive increase in the prevalence of BWSp over time, paralleling that of ART usage in the last decades.

Deconstructing age(s): an analysis of the different conceptions of age as a legal criterion for access to assisted reproductive technologies

Whether there should be restrictions for access to Assisted Reproductive Technologies (ART) is a matter of continuous medical, societal, and ethico-legal debate. One of the most controversial topics in this context is the use of parental age as a criterion to limit access to ART. Views are divided on whether there should be an upper age limit for one or both parents and on where such limits should be. Although this debate is centered around the issue of 'age' and although age-related limits are present in many legislations, the intrinsic ambiguity of the term `age' is largely overlooked. In this article, we build on gerontological, medical, and sociological literature on the concepts of 'age' and 'aging' to distinguish three conceptions of age that are relevant for ART regulation: the chronological, the biological, and the social-cultural one. Beyond mapping out these conceptions of age, we describe how they relate to ART and reproduction, and illustrate the advantages and disadvantages of relying on each of them as a basis for limiting ART access. Finally, we propose a template for defining legal age limits for ART access in the law, based on the refined understanding of the different conceptions of age that we outline and we discuss two potential objections to our proposal.

Morphogenesis of the human preimplantation embryo: bringing mechanics to the clinics

During preimplantation development, the human embryo forms the blastocyst, the structure enabling uterine implantation. The blastocyst consists of an epithelial envelope, the trophectoderm, encompassing a fluid-filled lumen, the blastocoel, and a cluster of pluripotent stem cells, the inner cell mass. This specific architecture is crucial for the implantation and further development of the human embryo. Furthermore, the morphology of the human embryo is a prime determinant for clinicians to assess the implantation potential of in vitro fertilized human embryos, which constitutes a key aspect of assisted reproduction technology. Therefore, it is crucial to understand how the human embryo builds the blastocyst. As any material, the human embryo changes shape under the action of forces. Here, we review recent advances in our understanding of the mechanical forces shaping the blastocyst. We discuss the cellular processes responsible for generating morphogenetic forces that were studied mostly in the mouse and review the literature on human embryos to see which of them may be conserved. Based on the specific morphological defects commonly observed in clinics during human preimplantation development, we discuss how mechanical forces and their underlying cellular processes may be affected. Together, we propose that bringing tissue mechanics to the clinics will advance our understanding of human preimplantation development, as well as our ability to help infertile couples to have babies.

Cross-Border Reproductive Care: Psychological Distress in A Sample of Women Undergoing In Vitro Fertilization Treatment with and without Oocyte Donation

Background

Cross-border reproductive care (CBRC) refers to the movement of patients to foreign countries for fertility treatment. Limited evidence indicates that this phenomenon is associated with a risk of psychologi- cal distress, but few studies on the psychological impact of CBRC are currently available. The aim of this study was to compare the anxiety and depression levels of a group of cross-border patients with a local Spanish patient group, both of which underwent in vitro fertilization (IVF) treatment. We also sought to explore the clinical, sociodemographic and personality profiles of the CBRC group and local women.

Materials and Methods

This present cross-sectional study was conducted on 161 infertile females (71 CBRC patients and 90 local women) who were undergoing IVF treatment. The following questionnaires were used to collect data: Spielberger State Anxiety Inventory (STAI-S), the Beck Depression Inventory-II (BDI-II) and the Zuckerman-Kuhlman Personality Questionnaire (ZKPQ). Sociodemographic, clinical, reproductive and CBRC variables were also recorded.

Results

CBRC patients, specifically CBRC oocyte recipients, showed higher levels of anxiety compared to lo- cal women. However, no significant differences in depression scores were found between both groups. Finally, when analysing personality, the Activity scale scores of the ZKPQ were found to be higher in CBRC oocyte recipients, which indicated a greater tendency for general activity and higher energy levels.

Conclusion

CBRC oocyte recipient women may have greater vulnerability to anxiety than local women prior to infertility treatment. Screening and psychological support protocols for anxiety in this population should be considered.

Pregnancy outcomes after frozen-thawed single euploid blastocyst transfer following IVF cycles using GNRH agonist or HCG trigger for final oocyte maturation

PURPOSE

To assess whether GnRH agonist trigger impacts the implantation potential of euploid embryos.

METHODS

Retrospective cohort study done at an academic IVF center evaluating frozen-thawed embryo transfer (FET) cycles in which single-euploid blastocysts were transferred between 2014 and 2019. All embryos were generated in an IVF cycle which used GnRHa or hCG trigger and then were transferred in a programmed or natural FET cycle. Only the first FET cycle was included for each patient. Primary outcome was ongoing pregnancy rate or live birth rate (OPR/LBR). Secondary outcomes were implantation rate (IR), clinical pregnancy rate (CPR), clinical loss rate (CLR), and multiple pregnancy rate (MPR). Logistic regression was performed to control for confounding variables. A p value of < 0.05 was considered statistically significant.

RESULTS

Two hundred sixty-three FET cycles were included for analysis (GnRHa = 145; hCG = 118). The GnRHa group was significantly younger (35.2 vs. 37.5 years) and had higher AMH values (4.50 ng/ml vs. 2.03 ng/ml) than the hCG group, respectively (p < 0.05). There was no significant difference in OPR/LBR (64.1% (93/145) vs. 65.3% (77/118); p = 0.90) between the GnRHa and hCG groups, respectively. There was also no significant difference in IR, CPR, CLR, or MPR between groups. After controlling for confounding variables, the adjusted odds ratio for OPR/LBR was 0.941 (95% CI, 0.534-1.658); p = 0.83) comparing GnRHa to hCG. Pregnancy outcomes did not significantly differ when groups were stratified by age (< 35 vs. > 35 years old).

CONCLUSIONS

Our findings confirm that euploid embryos created after hCG or GnRHa trigger have the same potential for pregnancy.

Detection of Y Chromosome Microdeletions and Hormonal Profile Analysis of Infertile Men undergoing Assisted Reproductive Technologies

Background

Y chromosome deletions (YCDs) in azoospermia factor (AZF) region are associated with ab- normal spermatogenesis and may lead to azoospermia or severe oligozoospermia. Assisted reproductive tech- nologies (ART) by intracytoplasmic sperm injection (ICSI) and testicular sperm extraction (TESE) are com- monly required for infertility management of patients carrying YCDs. The aim of this study was to estimate the frequency of YCDs, to find the most frequent variant in infertile men candidate for ART and to compare YCD distribution with a control fertile group. The semen parameters, hormonal profiles and ART outcomes of the infertile group were studied.

Materials and Methods

This case-control study consisted of 97 oligozoospermic or non-obstructive azoospermic (NOA) infertile men, who had undergone ART, as the case group and 100 fertile men as the control group. DNA samples were extracted from blood samples taken from all 197 participants and YCDs were identified by multiplex polymerase chain reaction (PCR) of eight known sequence-tagged sites. The chi-square test was used to compare the mean values of hormone and sperm parameters between the two groups. P<0.05 was considered statistically significant.

Results

No YCD was detected in the control group. However, 20 out of 97 (20.6%) infertile men had a YCD. AZFc, AZFbc and AZFabc deletions were detected in 15 (75%), four (20%) and one (5%) YCD-positive patients. No fer- tilization or clinical pregnancy was seen following ICSI in this sub-group with YCD. The mean level of FSH was significantly higher in the group with YCD (28.45 ± 22.2 vs. 4.8 ± 3.17 and 10.83 ± 7.23 in YCD-negative patients with and without clinical pregnancy respectively).

Conclusion

YCD is frequent among NOA men and YCD screening before ART and patient counseling is thus strongly recommended.

The placenta: phenotypic and epigenetic modifications induced by Assisted Reproductive Technologies throughout pregnancy

Today, there is growing interest in the potential epigenetic risk related to assisted reproductive technologies (ART). Much evidence in the literature supports the hypothesis that adverse pregnancy outcomes linked to ART are associated with abnormal trophoblastic invasion. The aim of this review is to investigate the relationship between epigenetic dysregulation caused by ART and subsequent placental response. The dialogue between the endometrium and the embryo is a crucial step to achieve successful trophoblastic invasion, thus ensuring a non-complicated pregnancy and healthy offspring. However, as described in this review, ART could impair both actors involved in this dialogue. First, ART may induce epigenetic defects in the conceptus by modifying the embryo environment. Second, as a result of hormone treatments, ART may impair endometrial receptivity. In some cases, it results in embryonic growth arrest but, when the development of the embryo continues, the placenta could bring adaptive responses throughout pregnancy. Amongst the different mechanisms, epigenetics, especially thanks to a finely tuned network of imprinted genes stimulated by foetal signals, may modify nutrient transfer, placental growth and vascularization. If these coping mechanisms are overwhelmed, improper maternal-foetal exchanges occur, potentially leading to adverse pregnancy outcomes such as abortion, preeclampsia or intra-uterine growth restriction. But in most cases, successful placental adaptation enables normal progress of the pregnancy. Nevertheless, the risks induced by these modifications during pregnancy are not fully understood. Metabolic diseases later in life could be exacerbated through the memory of epigenetic adaptation mechanisms established during pregnancy. Thus, more research is still needed to better understand abnormal interactions between the embryo and the milieu in artificial conditions. As trophectoderm cells are in direct contact with the environment, they deserve to be studied in more detail. The ultimate goal of these studies will be to render ART protocols safer. Optimization of the environment will be the key to improving the dialogue between the endometrium and embryo, so as to ensure that placentation after ART is similar to that following natural conception.

Medications as a source of paraben exposure

BACKGROUND

Parabens are used as antimicrobial excipients in some pharmaceuticals. Parabens may adversely affect reproduction.

OBJECTIVES

Determine whether paraben-containing medication contributes to high urinary paraben concentrations.

METHODS

Individuals at a fertility clinic provided multiple urine samples during evaluation/treatment and reported 24-h use of medications and personal care products (PCP). Repeated measures models compared specific gravity-adjusted urinary methyl, propyl, and butyl paraben concentrations between samples "exposed" and "unexposed" to paraben-containing medication.

RESULTS

Eleven participants contributed 12 exposed and 45 unexposed samples, among which paraben concentrations did not differ. Use within 7h was associated with 8.7-fold and 7.5-fold increases in mean methyl (P=0.11) and propyl (P=0.10) paraben concentrations, respectively, after adjusting for PCP use. However, these associations decreased to 1.3-fold (P=0.76) and 2.6-fold (P=0.34), respectively, after removal of one influential individual.

CONCLUSION

Paraben-containing medications contributed to higher urinary paraben concentrations within hours of use.

Remifentanil versus Fentanyl for Assisted Reproductive Technologies: Effect on Hemodynamic Recovery from Anesthesia and Outcome of ART Cycles

BACKGROUND

We conducted this study to compare the outcome of assisted reproductive technology (ART) procedures and recovery from anesthesia in women who received opioid analgesia with remifentanil versus fentanyl.

MATERIALS AND METHODS

This double-blind, randomized clinical trial was carried out in the Yazd Research and Clinical Center for Infertility, Yazd, Iran. We studied 145 women who were participants in an ART program. During the first phase of the study, all patients underwent induction of anesthesia with thiopental and received analgesia with remifentanil or fentanyl. The primary endpoint was pregnancy rate per transfer. The numbers of oocytes collected, fertilized and cleaved were recorded, as was the number of oocytes transferred and recovery profile. In the second phase of the study, all patients were followed for outcome of ART cycle.

RESULTS

This study suggested that in women undergoing transvaginal ultrasound-guided oocyte retrieval procedures, the likelihood of a successful pregnancy was higher with a remifentanil-based monitored anesthesia care (MAC) technique than with a fentanyl-based MAC technique. The recovery from anesthesia was significantly better in the remifentanil group versus fentanyl group.

CONCLUSION

The results of this study suggest that remifentanil in clinical practice is superior to fentanyl (

REGISTRATION NUMBER

IRCT201009283468N3).