The probability of a successful treatment of infertility by in-vitro fertilization

Abstract

The objective of this study was to define several estimates of the success rate of in-vitro fertilization and embryo transfer treatment in relation to treatment outcome. The data were collected in a retrospective study of 591 patients treated during 3 years in one Belgian university hospital. Several models used for evaluating the treatment of infertility were fitted to the data (logistic model, binomial model, double binomial model, exponential model, the Speirs model. The number of oocytes retrieved and the proportion of fertilized oocytes at the first attempt can be used as prognostic factors. According to these factors, the success rate after five attempts varies from 28 to 88%.

The statistical implication of the 'number of replacements' in embryo transfer

“…The dramatic increase in multiple births at three replacements is very evident In Tables FI and HI, the very large numbers of transfers permits a valid visual interpretation of the data. However, for small data sets involving variable numbers of embryo transfers, a comprehensive statistical evaluation, perhaps using the methods of Bouckaert et al (1994) or Walters (1989), is imperative in order to guarantee reliable inferences. The very simple, albeit statistically rigorous, tests used by Azem et al (1995) are not really adequate in these circumstances.…”

“…Other factors being equal, increasing or decreasing the number of replacements per transfer in IVF has an effect which is fairly regular and can be modelled quite successfully in probabilistic terms (see Bouckaert et al, 1994;Walters, 1989). Unusual or unexpected conclusions quoted in the literature are often derived from small studies in which the absence of a statistically significant effect is taken as evidence that the effect does not exist.…”

Preretrieval predictors of pregnancy in IVF

“…Many IVF-ET programs conduct aggressive COH in order to obtain the maximum number of oocytes. The rationale for this approach is provided by observations of a positive correlation between pregnancy rates, level of estradiol on the day of administration of hCG, number of follicles, size of leading follicles, and number of retrieved oocytes (4,5,9,10). These findings, however, contrast with other reports suggesting that fertilization rates, implantation rates, and pregnancy rates decline in cycles associated with a high number of preovulatory follicles and a high number of oocytes (11)(12)(13).…”

“…Stimulation of release of endogenous gonadotropins by clomiphene citrate or the administration of exogenous gonadotropins promotes recruitment and maturation of a cohort of antral follicles (1). Thus, COH increases the probability of obtaining several oocytes and several embryos, resulting in improved pregnancy rates (2)(3)(4)(5). Over the last several years, many IVF-ET programs have performed COH by administration of gonadotropins in conjunction with "long" protocols of GnRH agonists for hypothalamic-pituitary suppression.…”

Impact of quantitative parameters, such as number of retrieved oocytes, number of transferred embryos and availability of surplus embryos for cryopreservation, on clinical pregnancy rates in ART

“…While looking through relevant scientific literature, one can find various predictive models in reproductive medicine, attributed to male, female and embryonic factors [1][2][3]. Predictive models of embryological origin are: availability of top-quality embryos [4], best quality embryo score [5,6], embryo development [5,7], embryonic morphology [5], fertilization rate [8] and number of retrieved oocytes [4,5,9] and finally the embryonic quality prediction by morphokinetics as presented by embryoscope follow-up. There is agreement in the literature that there is a correlation between the number of oocytes and the number of transferred embryos and the implantation rates [6,10].…”