RELATIONSHIPS BETWEEN THE DEVELOPMENTAL POTENTIAL OF HUMAN IN-VITRO FERTILIZATION EMBRYOS AND FEATURES DESCRIBING THE EMBRYO, OOCYTE AND FOLLICLE

This paper investigates the relationship of features of in-vitro ferti lization (IVF) embryos and the associated oocyte and follicle to the o utcome of transfer. It differs from previous studies in including a ra nge of features (n = 53) and in using class probability tree analysis. This is a non-parametric multivariate method which expresses relation ships as simple rules of features characterizing the 'take home baby' and 'no take home baby' (negative pregnancy test) classes of embryo ba tches, Data were analysed retrospectively. Fifty-three (embryo, oocyte and follicular) features for each of the three embryos in the transfe rred batch were collected for 200 IVF patients. Each batch of three em bryos was described by a representative value for each feature. The re lationship between features and outcome of transfer was analysed. Only four of the 53 features were identified as predictive. However, an ap propriate combination of these four (embryo grade, cell number, follic le size and follicular fluid volume) achieved satisfactory predictivit ies while offering a simplified and more quantitative basis than regul arly used criteria, The key component of the composite embryo grading allotted by embryologists turned out to be cell number. The existing p redictive use of follicular size was corroborated and an independent a dditional predictive contribution of follicular fluid volume was found . The study also suggests that the 49 remaining features have little a dditional predictive value.