ABSTRACT
The adage ex ovo omni, ‘from the ovum all’, was first advanced by Harvey in the 17th century to explain the origin of life; this observation retains a measure of currency in the 21st century, as basic research findings and clinical outcomes indicate the extent to which the developmental competence of the embryo is already determined in the oocyte prior to fertilization.1-3 Two important issues related to the oocyte in contemporary infertility treatments, such as those using in vitro fertilization (IVF) are (1) whether noninvasive methods for follicular assessments can be sufficiently sensitive to distinguish between morphologically comparable oocytes with different developmental competence, and (2) when and how defects arise in the oocyte that have adverse effects on embryo development.
