Introduction: Examining the Many Potential Reasons Why Euploid Blastocysts Do Not Always Result in Viable Pregnancies: Part 1

The environment of the oocyte and embryo includes the metabolic effects of aging, lifestyle issues, psychological stress, nutritional supplements/replacements, cellular energy levels, endocrine and paracrine factors, the cumulus, exogenous gonadotropins and adjunctive medications, culture media, and the in vitro fertilization laboratory's conditions and manipulations. These complex factors, which will be examined in the following series of reviews, explain in part why not all euploid blastocysts result in viable pregnancies.