Advancing ovarian folliculometry with selective plane illumination microscopy

6-Gingerol and Astaxanthin Mitigate the Effects of Stearic Acid in Pig Oocyte Maturation

Elevated non-esterified fatty acids (NEFAs), particularly stearic acid (SA), have a deleterious effect on oocyte maturation, leading to developmental damage and reproductive issues. High SA levels disrupt metabolic processes, inducing lipotoxicity that impairs oocyte quality and contributes to reproductive failures through early embryonic losses. This research investigates the lipotoxic effects of SA and assesses the protective potential of 6-Gingerol (6-G) and Astaxanthin (AX) on porcine oocytes during in vitro maturation (IVM). Herein, 6100 cumulus-oocyte complexes (COCs) were exposed to various concentrations of SA (25-250 μM) to elucidate the concentration-dependent effect on oocyte viability, polar body extrusion (PBE) and cumulus cell expansion index (CCEI). However, the efficacy of 6-G (5-15 μM) and AX (2.5 μM) in combination with SA at 150 μM (SA6) concentration was evaluated to mitigate these adverse effects. The results indicated that SA6 substantially reduced oocyte viability, PBE and CCEI, demonstrating its toxic impact on oocyte developmental competence (p < 0.0001). Moreover, treatment with antioxidants such as SA6 + 6-G (10 μM) and SA6 + AX showed a considerable increase in viability and PBE compared to SA6 alone (p < 0.05). These findings demonstrate the importance of lipid metabolism in oocyte health, where dysregulation impairs reproductive capacity. Both 6-G and AX protected against lipotoxicity induced by SA6 while enhancing lipid homeostasis and the anti-oxidative defences necessary for maintaining cellular integrity. This study finds substantial evidence that optimising the microenvironment with specific antioxidants can improve oocyte quality and provide invaluable knowledge in reproductive technologies and fertility treatments.

Brilliant cresyl blue enhanced optoacoustic imaging enables non-destructive imaging of mammalian ovarian follicles for artificial reproduction

In the field of reproductive biology, there is a strong need for a suitable tool capable of non-destructive evaluation of oocyte viability and function. We studied the application of brilliant cresyl blue (BCB) as an intra-vital exogenous contrast agent using multispectral optoacoustic tomography (MSOT) for visualization of porcine ovarian follicles. The technique provided excellent molecular sensitivity, enabling the selection of competent oocytes without disrupting the follicles. We further conducted in vitro embryo culture, molecular analysis (real-time and reverse transcriptase polymerase chain reaction) and DNA fragmentation analysis to comprehensively establish the safety of BCB-enhanced MSOT imaging in monitoring oocyte viability. Overall, the experimental results suggest that the method offers a significant advance in the use of contrast agents and molecular imaging for reproductive studies. Our technique improves the accurate prediction of ovarian reserve significantly and, once standardized for in vivo imaging, could provide an effective tool for clinical infertility management.

Initial ovarian sensitivity index predicts embryo quality and pregnancy potential in the first days of controlled ovarian stimulation

BACKGROUND

To determine if a modified ovarian sensitivity index (MOSI), based on initial follicular measurements and the initial follicle-stimulating hormone (FSH) dose, can predict the production of high-quality embryos for successful implantation during in vitro fertilization (IVF).

METHODS

This study consisted of two phases: 1) a retrospective study and 2) a prospective observational study. For the first phase, 363 patients charts were reviewed, of which 283 had embryos transferred. All women underwent a standardized antagonist-based IVF protocol. At the first follow-up (Day 3/4), the number and size of the follicles were determined. MOSI was calculated as ln (number follicles (≥6 mm) × 1000 / FSH initial dose). Afterward, the number and quality of the ova, embryo development, and the number and quality of the blastocysts were determined. Embryo implantation was confirmed by β-hCG. For the second phase, 337 IVF cycles were followed to determine MOSI's accuracy.

RESULTS

MOSI could predict the production of ≥4 high-quality embryos by Day 2 (AUC = 0.69, 95%CI:0.63-0.75), ≥2 blastocysts (AUC = 0.74, 95%CI:0.68-0.79), and ≥ 35% rate of blastocyst formation (AUC = 0.65, 95%CI:0.58-0.72). Using linear regression, MOSI was highly associated with the number of ova captured (β = 5.15), MII oocytes (β = 4.31), embryos produced (β = 2.90), high-quality embryos (β = 0.98), and the blastocyst formation rate (β = 0.06, p < 0.01). Using logistic regression, MOSI was highly associated with achieving ≥4 high-quality embryos (odds ratio = 2.80, 95%CI:1.90-4.13), ≥2 blastocysts (odds ratio = 3.40, 95%CI:2.33-4.95), and ≥ 35% blastocysts formation rate (odds ratio = 1.96, 95%CI:1.31-2.92). This effect was independent of age, BMI, and antral follicle count. For implantation, MOSI was significantly associated with successful implantation (odds ratio = 1.79, 95%CI:1.25-2.57). For the prospective study, MOSI was highly accurate at predicting ≥6 high-quality embryos on Day 2 (accuracy = 68.5%), ≥6 blastocysts (accuracy = 68.0%), and a blastocyst formation rate of ≥35% (accuracy = 61.4%).

CONCLUSION

MOSI was highly correlated with key IVF parameters that are associated with achieved pregnancy. Using this index with antagonist cycles, clinicians may opt to stop an IVF cycle, under the assumption that the cycle will fail to produce good blastocysts, preventing wasting the patient's resources and time.