Pregnancy Rate and Pregnancy Outcome Associated with Laboratory Evaluation of Spermatozoa, Oocytes, and Pre-Embryos

Abstract

There are very few non-invasive methods currendy available for determining the quality of gametes and pre-implantation embryos. Because sperm collection is easier than oocyte collection, and because the numbers of available sperm are so far in excess of available oocytes, the opportunity to examine large populations of sperm is possible within an in vitro fertilization setting. It follows that invasive testing may be performed on sperm without fear of compromising a given patient’s chances for establishing pregnancy. Unfortunately, embryologists must rely primarily on gross morphology and developmental rate in order to make comparable assessments of the oocyte and developing conceptus; both an unreliable and uninformative means, yet the only means possible when the desire is to reduce potential danger to the oocyte and pre-embryo. Despite these limitations, various associations may be noted between the factors of gross analysis and the ability to contribute to ongoing pregnancy. While these factors may differ between sperm and oocytes, the additive effect of each factor may build a base upon which to estimate the potential for success.