P-543 Higher maternal age alters the insulin/IGF system and intracellular lipid metabolism of the endometrium and in the preimplantation embryo – insights from the rabbit model

Abstract Study question Our aim was to analyse the embryo-maternal-interaction, focusing on the insulin/IGF-system and lipid metabolism on day 6 of pregnancy in reproductive young and old rabbits. Summary answer Advanced maternal age has a decisive effect on maternal and embryonic insulin/IGF-signalling and lipid metabolism, leading to higher embryo loss already during preimplantation period. What is known already The reproductive potential in women declines with age. Molecular and biochemical mechanisms involved in age-related infertility and their impact on embryo-maternal-interaction during early pregnancy are still not completely understood. However, establishment of a successful pregnancy depends on the physiological condition of the mother and a continuous dialogue with the developing embryo. The insulin/IGF-system plays a pivotal role in this embryo-maternal crosstalk, connecting maternal insulin/IGF with embryonic metabolism, cell proliferation and differentiation. Study design, size, duration We used the rabbit as reproductive model to investigate maternal age-related alterations in embryo-maternal-interaction during preimplantation period. Compared to humans, the rabbit shares high similarities in early embryo development, gastrulation and lipid metabolism (DOI: 10.1530/REP-12-0091 and DOI: 10.1093/ajcn/62.2.458S). A total of 50 young (16-20 weeks) and 31 old (