A REGRESSION-MODEL FOR THE RATE OF SUCCESS OF IN-VITRO FERTILIZATION

The treatment of infertility by in vitro fertilization involves severa l aspects of human reproductive physiology. Since failures are still n umerous and since improved techniques are becoming increasingly availa ble, it is important to develop a model where the components of succes s are identified, allowing estimation of the occurrence of these compo nents of success in the infertile population. The model of Speirs redu ces these components to two: uterine receptivity and embryo viability. The probabilities of uterine receptivity and embryo viability were es timated here in a retrospective study of patients in a Belgian hospita l sample. For comparison, Australian and U.S. data were used. It was s hown that the estimate of uterine receptivity for the Belgian sample i s located between the estimates for Australian and U.S. samples. In vi ew of the psychological problem of repeated unsuccessful attempts at i n vitro fertilization in some patients, it is important to be able to single out some prognostic factors that would allow more precise estim ation of the probability for success in each case. A regression method was developed for that purpose. Only the effect of age, in the Belgia n sample, was found to influence uterine receptivity significantly.