Marta Méndez

Purpose Poor ovarian response and primary ovarian insufficiency remain major challenges in assisted reproductive technologies. Recent advances propose mechanical approaches—such as in vitro activation, drug-free IVA, and whole ovarian laparoscopic incision (WOLI)—as well as biological strategies like platelet-rich plasma (PRP) injections to improve ovarian function. This study aims to evaluate the impact of WOLI and PRP on ovarian follicular activation, with a particular focus on the associated biomechanical alterations in the ovarian cortex. Methods Experimental pilot study includes six aged female Merino sheep. Group A underwent WOLI on one ovary, and group B received PRP injections. Contralateral ovaries served as controls. Laparoscopic bilateral oophorectomies were performed at 2, 4, and 6 months. Atomic force microscopy (AFM) measured ovarian cortical stiffness, and histological analysis assessed follicular activation. Analyses were performed by comparing the operated ovary to the contralateral, non-operated ovary. Results AFM measurements showed that in group A, ovarian stiffness significantly increased at 6 months (8.683 kPa vs. 5.551 kPa; p < 0.001), with no significant differences at 2 or 4 months. In group B, stiffness increased significantly at 2 months (11.177 kPa vs. 6.590 kPa; p < 0.001), but not at 4 or 6 months post-intervention. Growing follicle proportions differed between treated and control ovaries respectively, with activation at 2 months (58.95% vs. 29.73%) in group A and 6 months in group B (53.01% vs. 20.33%). Conclusion The study suggests that the activating effect on ovarian folliculogenesis of both the surgical procedure and PRP administration shows a different time course and that could be related to its effect on ovarian cortex mechanobiology.

Endometriosis affects about 10% of reproductive-aged women, characterized by endometrial-like tissue outside the uterus, leading to chronic inflammation. The exact cause remains unknown, though genetic and epigenetic factors are increasingly recognized alongside traditional theories. The disease manifests in forms such as endometriomas, whether superficial or peritoneal, and deep infiltrating lesions, often causing chronic pain and infertility. Infertility affects nearly 50% of patients, requiring expensive treatments like in vitro fertilization. Oxidative stress plays a key role in endometriosis, with sirtuins, especially SIRT3, emerging as important regulators. SIRT3, located in mitochondria, helps manage oxidative stress and redox balance. Despite extensive research, no diagnostic biomarkers exist. This longitudinal study compares oxidative stress markers and SIRT3 levels in patients with different endometriosis types. While classic oxidative stress markers showed no significant differences, higher SIRT3 levels were observed in peripheral blood mononuclear cells of patients with deep endometriosis. Additionally, patients with prior surgeries had elevated SIRT3 levels, indicating a possible link between disease severity and SIRT3 expression. The findings suggest SIRT3 as a potential therapeutic target in endometriosis management.

Numerous studies have compared ovarian tissue cryopreservation methods, including slow freezing/rapid thawing (SF/RT) and vitrification/warming (V/W), focusing on morpho-functional status, follicle density, stromal cell integrity, and gene expression during in vitro culture. However, results remain inconclusive. This study aims to evaluate the effects of SF/RT and V/W on the ovarian cortex's biomechanical properties. Human ovarian biopsies were taken from five women between 32 and 45 years undergoing laparoscopic surgery for tubal sterilization. For each patient, one small sample of fresh tissue was used as control, and the remaining tissue were vitrified or frozen by slow freezing method. The tissue stiffness of the cryopreserved samples at the micrometer scale was measured by Atomic Force Microscopy after thawing and warming, depending of the cryopreservation method. The median stiffness of the ovarian cortex was 3670.00 Pa (Pascal) (IQR 2146.4) in the control group. After cryopreservation, the median stiffness slightly decreased to 1305.90 Pa (IQR 503.51) with SF/RT and to 2284.50 Pa (IQR 3314.40) with V/W. General linear model analysis revealed no significant effect of cryopreservation method on the ovarian cortex stiffness (F=2.750, p=0.071). No significant differences were observed based on the intra-sample zone studied by AFM. However, a significant inter-patient effect on tissue stiffness was identified (F=3.958, p=0.006). The study findings suggest that ovarian tissue freezing methods do not have a relevant impact on functional aspects of the extracellular matrix (ECM), suggesting that given the logistical advantages of vitrification, this technique should be prioritized.

The relationship between premature ovarian insufficiency (FXPOI) and premutation in the FMR1 gene is well established. In recent years, though, a potential relationship between the latter and a low ovarian reserve has been suggested. To explore it, we conducted a retrospective study in an IVF program at a university tertiary referral center in Barcelona (Spain). Data were obtained retrospectively from a total of 385 women referred for FMR1 gene testing at our institution from January 2018 to December 2021. We compared the prevalence of FMR1 gene premutation between 93 of them, younger than 35 years, with a diminished ovarian reserve (DOR), characterized by levels of anti-Mullerian hormone < 1.1 ng/mL and antral follicle count < 5; and 132 egg donors screened by protocol that served as the controls. We found a higher prevalence of FMR1 premutation in the DOR group (seven patients (7.69%)) than in the control group (one patient (1.32%)), Fisher-exact test p-value = 0.012). We concluded that compared with the general population represented by young egg donors, the prevalence of FMR1 gene premutation is higher in young patients with a diminished ovarian reserve. Although these findings warrant further prospective validation in a larger cohort of patients within DOR, they suggest that, in clinical practice, FMR1 premutation should be determined in infertile young patients with DOR in order to give them adequate genetic counselling.

Purpose There is increasing evidence that the ovarian extracellular matrix (ECM) plays a critical role in follicle development. The rigidity of the cortical ECM limits expansion of the follicle and consequently oocyte maturation, maintaining the follicle in its quiescent state. Quiescent primordial, primary, and secondary follicles still exist in primary ovarian insufficiency (POI) patients, and techniques as in vitro activation (IVA) and drug-free IVA have recently been developed aiming to activate these follicles based on the Hippo signaling disruption that is essential in mechanotransduction. In this context, we analyze the effect of drug-free IVA in POI patients, comparing the relationship between possible resumption ovarian function and biomechanical properties of ovarian tissue. Methods Nineteen POI patients according to ESHRE criteria who underwent drug-free IVA by laparoscopy between January 2018 and December 2019 and were followed up for a year after the intervention. A sample of ovarian cortex taken during the intervention was analyzed by atomic force microscopy (AFM) in order to quantitatively measure tissue stiffness (Young’s elastic modulus, E) at the micrometer scale. Functional outcomes after drug-free were analyzed. Results Resumption of ovarian function was observed in 10 patients (52.6%) and two of them became pregnant with live births. There were no differences in clinical characteristics (age and duration of amenorrhea) and basal hormone parameters (FSH and AMH) depending on whether or not there was activation after surgery. However, ovarian cortex stiffness was significantly greater in patients with ovarian activity after drug-free IVA: median E = 5519 Pa (2260–11,296) vs 1501 (999–3474); p-value < 0.001. Conclusions Biomechanical properties of ovarian cortex in POI patients have a great variability, and higher ovarian tissue stiffness entails a more favorable status when drug-free IVA is applied in their treatment. This status is probably related to an ovary with more residual follicles, which would explain a greater possibility of ovarian follicular reactivations after treatment.