Assisting Nature

One of the major advancements in in vitro fertilization (IVF) has been the development of culture media that enhance gamete maturation in vitro and sustain embryo development up to the blastocyst stage. The deep understanding of the mechanisms involved in gametogenesis and the complex sequence of events surrounding nuclear and cytoplasmic maturation has also enabled the development of efficient in vitro maturation (IVM) protocols. This review outlines the major landmarks in the history of in vitro maturation of oocytes, the advantages and importance of its clinical application in human, especially in patients with Polycystic Ovary Syndrome (PCOS), Resistant Ovary Syndrome, high antral follicle count or oncology patients, as well as the safety and efficacy of the technique. IVM has not been shown yet to be as effective as controlled ovarian stimulation in terms of maturation rates, fertilization rates, and clinical outcome, possibly owing to a dysfunctional or asynchronous nuclear/cytoplasmic maturation process. A confusing set of IVM clinical protocols may also have contributed to the slow incorporation of the technology into routine IVF practice. However, recent improvements have led to comparable live birth rates between IVM and IVF, in women with high antral follicle count. The current status of IVM in the Assisted Reproductive Technology (ART) laboratory and its future perspectives, aiming to provide maximum fertility care to patients will be discussed.

Background:Endometrial scratching (ES) remains controversial regarding its potential effectiveness in improvingpregnancy rates. The objective of the present study was to assess the impact of endometrial fundal incision (EFI) duringhysteroscopy on reproductive outcomes in a population of oocyte recipients.Materials and Methods:A randomized controlled trial was conducted between 2020 and 2023 at the Third Departmentof Obstetrics and Gynecology, School of Medicine, Faculty of Health Sciences, Aristotle University of Thessalonikiand “Assisting Nature Centre of Reproduction and Genetics”. The study population consisted of women whounderwent hysteroscopy randomly assigned in a 1:1 ratio to either EFI (one to three months before embryotransferwith donor oocytes) or no intervention throughout office hysteroscopy. Clinical pregnancy and live birth rates werethe primary outcomes.Results:After the exclusion of patients with intraoperative diagnosed endometrial pathology, a total of 124 womenunderwent randomization. The pregnancy test was positive in 79% (n=49/62) of the women in the EFI compared to59.7% (n=37/62) in the hysteroscopy-only group (P=0.019), while the live birth rates did not differ between the twogroups (58.1%, n=36/62 vs. 51.6%, n=32/62, P=0.470).Conclusion:EFI during hysteroscopy seems to improve pregnancy rates in oocyte recipients without intrauterinepathology, while live birth rates are not affected by the EFI. These results should be interpreted with caution beforethe implementation of EFI in the routine in vitro fertilization (IVF) practice (registration number: NCT04580056).

Endometrial scratching (ES) during hysteroscopy before embryotransfer (ET) remains doubtable on whether it benefits the reproductive outcomes. The optimal technique is not clear and repeated implantation failure as a challenging field in in vitro fertilization (IVF) seems to be the springboard for clinicians to test its effectiveness. Medline, PMC, ScienceDirect, Scopus, CENTRAL, Google Scholar were searched from their inception up to April 2023 for studies to evaluate the effectiveness of adding endometrial scratching during hysteroscopy before ET. The initial search yielded 959 references, while 12 eligible studies were included in the analyses, involving 2,213 patients. We found that hysteroscopy and concurrent ES before ET resulted in a statistically significant improvement in clinical pregnancy rate (CPR) [RR = 1.50, (95% CI 1.30-1.74), p < 0.0001] and live birth rate (LBR) [RR = 1.67, (95% CI 1.30-2.15), p < 0.0001] with no statistically significant difference on miscarriage rate [RR = 0.80 (95% CI 0.52-1.22), p = 0.30]. Our meta-analysis suggests that hysteroscopy with concurrent ES may be offered in IVF before ET as a potentially improving manipulation. Future randomized trials comparing different patient groups would also provide more precise data on that issue, to clarify specific criteria in the selection of patients. PROSPERO (CRD42023414117).

Preimplantation Genetic Testing (PGT) is a special technique in Assisted Reproduction Field that is applied to avoid a variety of hereditary disorders. This case report presents the first experience with rare X-linked Choroideremia disease (CHM), which leads to total blindness in male members of the family. To achieve a live birth in this case a total of 3 IVF procedures and 3 PGT cycles were performed. The data in our case offer the chance to couples suffering from rare genetic ophthalmo-neurological diseases to have healthy offspring.

Artificial oocyte activation using calcium ionophores and enhancement of embryonic developmental potential by the granulocyte-macrophage colony-stimulating factor (GM-CSF) have already been reported. In this study, we evaluated the synergistic effect of these two methods on aged human unfertilized oocytes after intracytoplasmic sperm injection (ICSI). Then, we cultured the resulting embryos to the blastocyst stage and screened them for chromosomal abnormalities, to assess the safety of this protocol. Aged human oocytes deemed unfertilized after ICSI were activated, either by briefly applying the calcium ionophore A23187 alone (group A) or by briefly applying the ionophore and then supplementing the culture medium with recombinant human GM-CSF (rhGM-CSF) (group B). Next, the development was monitored in a time-lapse incubator system, and ploidy was analyzed by array comparative genomic hybridization (aCGH), after whole embryo biopsy and whole genome amplification. Differences between oocytes and resulting embryos in both groups were evaluated statistically. Oocytes unfertilized after ICSI can be activated with the calcium ionophore A23187 to show two pronuclei and two polar bodies. Addition of rhGM-CSF in the culture medium of A23187-activated oocytes enhances their cleaving and blastulation potential and results in more euploid blastocysts compared to the culture medium alone. This study shows that activating post-ICSI aged human unfertilized oocytes with a combination of a calcium ionophore and a cytokine can produce good-morphology euploid blastocysts.

A thin endometrium is one of the most difficult problems encountered in assisted reproduction every day practice. Whether a daily dose of 150IU HCG for 7days concomitant with estrogen administration in estrogen replacement cycles can increase the endometrial thickness and improve pregnancy outcome, was the objective of the current study. Seventeen infertile patients with successive implantation failures and resisting thin endometrium, being recipients of fresh donor or frozen embryos were recruited. This was a prospective cohort, proof of concept study, NCT01768247. On day-8 or 9 of the estrogen administration, and continuing 8mg estrogen per day, subcutaneous injections of 150IU HCG were initiated daily for 7days. After a week on HCG priming, (day-14 or 15) endometrial thickness was controlled with ultrasound, and progesterone was initiated. Mean endometrial thickness was increased from 5.2mm to 6mm (p = 0.008). 35.3% of the patients had more than 20% improvement of their endometrial thickness after HCG priming. 17% achieved an endometrial thickness more than 7mm, and 29.4% did not improve their thickness at all. Interestingly, from the later two became pregnant. Overall, 41% of them (7/17) finally delivered. One hundred fifty IU HCG endometrial priming for 7days in the proliferative phase of estrogen substituted cycles for frozen embryos is highly promising, as not only the thickness of the endometrium improves but also eventually the receptivity appears normalized.

Mouse sex determination provides an attractive model to study how regulatory genetic networks and signaling pathways control cell specification and cell fate decisions. This study characterizes in detail the essential role played by the insulin receptor (INSR) and the IGF type I receptor (IGF1R) in adrenogenital development and primary sex determination. Constitutive ablation of insulin/IGF signaling pathway led to reduced proliferation rate of somatic progenitor cells in both XX and XY gonads prior to sex determination together with the downregulation of hundreds of genes associated with the adrenal, testicular, and ovarian genetic programs. These findings indicate that prior to sex determination somatic progenitors in Insr;Igf1r mutant gonads are not lineage primed and thus incapable of upregulating/repressing the male and female genetic programs required for cell fate restriction. In consequence, embryos lacking functional insulin/IGF signaling exhibit (i) complete agenesis of the adrenal cortex, (ii) embryonic XY gonadal sex reversal, with a delay of Sry upregulation and the subsequent failure of the testicular genetic program, and (iii) a delay in ovarian differentiation so that Insr;Igf1r mutant gonads, irrespective of genetic sex, remained in an extended undifferentiated state, before the ovarian differentiation program ultimately is initiated at around E16.5. PMID: 23300479