Effect of single versus grouped culture of human cumulus-oocyte complexes in PCOS women treated with biphasic in vitro maturation: A sibling oocyte pilot study.

Purpose: This study investigated the differences in the maturation rate of single versus grouped cumulus-oocyte complexes (COCs) culture methods for capacitation in vitro maturation (CAPA-IVM) in women with polycystic ovary syndrome (PCOS). Methods: This study was performed at My Duc Phu Nhuan Hospital, Vietnam from October 1, 2020 to October 24, 2021. Women aged 18-37 years with a diagnosis of PCOS were recruited. COCs from each woman were randomly divided into two groups: single or grouped culture during CAPA-IVM culture. The primary outcome was the maturation rate. Results: A total of 322 COCs from 15 eligible women included were randomly assigned to the two study groups. The maturation rate was comparable between the single and grouped culture groups (61.3% vs. 64.8%; p = 0.56). There were no significant differences in the number of 2-pronuclei fertilized oocytes, number of day-3 embryos, and number of good-quality embryos in the two culture method groups. In the single culture group, COCs morphology was associated with the day-3 embryo formation rate but not the maturation rate. Conclusions: Comparable oocyte maturation and embryology outcomes between single and grouped COCs culture utilizing sibling COCs derived from women with PCOS suggest the feasibility of both methods for CAPA-IVM culture.

Non-invasive cumulus cell analysis can be applied for oocyte ranking and is useful for countries with legal restrictions on embryo generation or freezing.

RESEARCH QUESTION: Can a strategy for scoring oocyte quality, based on cumulus cell (CC) gene expression, prioritize oocytes with the highest implantation potential, while limiting the number of embryos to be processed in culture and the number of supernumerary embryos to be vitrified? DESIGN: An interventional, blinded, prospective cohort study was retrospectively analyzed. In the original study, patients underwent a fresh Day3 single embryo transfer with embryos ranked based on morphology and CC gene expression (Aurora Test). The additional ranking of the embryos with the Aurora Test resulted in significant higher clinical pregnancy and live birth rates. Now it is investigated if the Aurora Test ranking could be applied to select oocytes. The effect of an Aurora Test based restriction to 2 and 3 2PN or MII oocytes on clinical pregnancy and other outcomes, was analyzed in two subsets of patients with all 2PN (n = 83) or all MII oocytes (n = 45) ranked. RESULTS: Considering only the top three ranked 2PN oocytes, 95% of the patients would have received a fresh SET on Day3 resulting in 65% clinical pregnancies. This was not different from the pregnancy rate obtained in a strategy using all oocytes but significantly reduced the need for vitrification of supernumerary embryos by 3-fold. Considering only top-ranked MII oocytes gave similar results. CONCLUSIONS: In countries with legal restrictions on freezing of embryos, gene expression of CC can be used for the selective processing of oocytes and would thus decrease the twin pregnancy rate and workload, especially for embryo morphology scoring and transfers as the handling and processing of lower competence oocytes is prevented, while improving the ART outcome.

First characterization of preantral follicles in the ovaries of adult alpaca / Primera caracterización de folículos preantrales de ovario de alpaca adulta

It is a fact that while even basic reproductive information on alpacas is unavailable, the normal ovarian reserve of this species in comparison to other species is also unidentified. In this study, the ovarian preantral follicles in healthy adult alpacas were characterized in order to establish a general model to in vitro studies. Ten ovaries were collected from five adult alpacas. The ovarian cortex samples were fixed with paraformaldehyde and histological analysis was done. Normal and degenerated follicles percentages were determined. The normal follicles were measured and classified in primordial, transitional, primary and secondary stages. Most of the preantral follicles present in the ovarian cortex of alpacas were primordial and transitional stages; primary (6.10%) and secondary (0.37%) follicles were rarely found. The primary and secondary follicles were larger in diameter when compared with the primordial and transitional follicles. The largest oocyte diameter was recorded in the secondary follicles (P < 0.05). This study serves to establish a biological model for future reproduction studies in Alpacas or as possible biological model for studies of folliculogenesis in humans(AU)

Es un hecho que, si bien no se dispone de información reproductiva básica sobre las alpacas, la reserva ovárica normal de esta especie en comparación con otras especies tampoco está identificada. En este estudio, se caracterizaron los folículos preantrales ováricos en alpacas adultas sanas. Se recogieron diez ovarios de cinco alpacas adultas. Las muestras de la corteza ovárica se fijaron con paraformaldehído y se realizó un análisis histológico. Se determinaron los porcentajes de folículos normales y degenerados. Los folículos normales se midieron y clasificaron en estadios: primordiales, de transición, primarios y secundarios. La mayoría de los folículos preantrales presentes en la corteza ovárica de las alpacas eran estadios primordiales y de transición; Raras veces se encontraron folículos primarios (6.10%) y secundarios (0.37%). Los folículos primarios y secundarios tenían un diámetro mayor en comparación con los folículos primordiales y de transición. El mayor diámetro de ovocitos se registró en los folículos secundarios (P <0.05). Este estudio sirve para establecer un modelo biológico para futuros estudios de reproducción en alpacas o como posible modelo biológico para estudios de foliculogénesis en humanos(AU)