#185 : Embryos Derived from Prepubertal Hyperglycemic Mice Show Differential Response to Oxygen Tension In Vitro

Abstract

Background and Aims: Response of preimplantation embryos to varying oxygen tensions, when cultured in vitro, has shown conflicting results. Though physiological or low oxygen culture is gaining popularity in IVF programs, how oxygen tension influences the behavior of embryos derived from pathological conditions is unknown. Since there has been an increasing trend in the incidence of diabetes in children and young adults, this study is aimed to look at the functional ability of embryos derived from experimentally induced hyperglycemic mice at the prepubertal phase of life to varying oxygen tension in vitro. Method: The experimentally induced hyperglycemic state was monitored in the prepubertal phase (3 to 6 weeks), followed by oocyte quality assessment, in vitro maturation potential, mitochondrial status, and spindle integrity analysis. Oocytes were then fertilized and cultured at high/atmospheric ([Formula: see text] 19%) and low/physiological ([Formula: see text]5%) oxygen tension until 96 h in vitro. Embryo quality and developmental progression, blastocyst rate, apoptosis, inner cell mass (ICM) outgrowth proliferation, and expression of Hif1[Formula: see text] were assessed. Results: Prepubertal hyperglycemia did not affect the ovarian reserve significantly; however, the maturation potential (P<0.001), mitochondrial integrity (P<0.01), and meiotic spindle assembly (P<0.05–0.001) in oocytes were altered significantly. Importantly, such oocytes showed better functional ability during the preimplantation phase of development when cultured at low oxygen tension. Hif1[Formula: see text] transcripts in ICM outgrowths were significantly higher (P<0.05) in low oxygen tension compared to atmospheric oxygen tension. Conclusion: Embryo culture in low oxygen tension appears beneficial for embryos derived from hyperglycemic mothers with respect to developmental competence and retaining genetic integrity. ART clinics need to customize their embryo culture strategies based on patient’s physiological and pathological conditions.