Assisted reproductive technologies (ART) are used to increase chance of pregnancy in infertile couples and increase number of offspring from valuable donor cows. However, high doses of gonadotropins used during ART to stimulate growth of large numbers of ovulatory follicles are correlated with high oocyte and embryo wastage and decrease live birth rates in women. Whether these excessive gonadotropin treatments during ART decrease ovarian function and embryo survival and the associated mechanisms are unknown. In addition, the major reason women seek ART is because they have a small ovarian reserve (total number of morphologically healthy follicles/oocytes in ovaries) which is characterized by infertility, hypersecretion of FSH during menstrual cycles, and poor response to superovulation. Although previous superovulation studies in bovine have consistently found the same results associated with increasing doses of gonadotropins, the size of the ovarian reserve was not established, and various breeds, ages and parities were utilized in a cross-sectional experimental design. Through ultrasonography, I have selected small ovarian reserve, low antral follicle count (marker for small ovarian reserve) virgin Holstein heifers to best replicate infertility seen in women. Based on these observations, I hypothesize that excessive doses of FSH during ART and the high endogenous secretion of FSH in individuals with a small ovarian reserve are detrimental to ovarian function, oocyte quality and embryo survival.
Published on September 17, 2019