In a study concerned with risk factors with an impact on the success of infertility treatment by methods of in vitro fertilization (IVF) the authors present the initial results obtained in a group of 42 women: 28 of them never smoked, 6 were ex-smokers and 8 smoked also in the course of treatment. The smokers had significantly higher cadmium blood levels than non-smokers (0.58 ng.ml-1 vs.0.31 ng.ml-1) while the values of Cd residues were independent on smoking (mean 0.12 ng,ml-1).The follicular levels of different sex hormones before the onset of hormonal stimulation were similar in smokers and non-smokers and there were no differences in the application of different therapeutic procedures. The fertilization ratio was significantly lower in smokers and ex-smokers as compared with women who never smoked: while in non-smokers 61.2% oocytes could be fertilized, in ex-smokers only 40.1% and in women who smoked during IVF only 25.1% oocytes. Among smokers there were 2-3 times as many where it did not prove possible to ensure even the development of one embryo as compared with ex-smokers and women who never smoked (62.5% vs.20.0% and 28.6% resp.). Among women who became pregnant after a single cycle of IVF therapy were non-smokers only.

        Key words: assisted reproduction - in vitro fertilization - effect of smoking