IVF success rates clearly demonstrate a dramatic decline as maternal age approaches and pass the middle 30s. Clinical data suggests the decline in embryo implantation rate with increased maternal age is an “embryo problem” and not a uterine problem since use of donated oocytes results in high implantation and pregnancy rates in the same patient population.
Secondly, it suggests that the embryo problem originates from the oocyte. The mechanisms of cytoplasmic anomalies underlying poor oocyte and embryo health are not well elucidated and present important new areas of research in IVF. Abnormalities in ooplasmic level and/or the distribution of metabolic stores, structural proteins, mitochondria, RNAs may lead to aneuploidy or genetic abnormalities or to other cellular conditions that eventuate in a poor prognosis for the embryo viability and quality.
The explanation of basic scientific mechanisms responsible for oocyte and embryo competence is crucial for the future development of novel diagnostics and therapeutics in assisted reproduction (ART).