Objective: Mapping of the socioeconomic background of opioid-addicted pregnant women and women included in substitution therapy. Determination of the effect of substitution on the course of pregnancy and delivery in drug-addicted pregnant women. Design of the study: A three-year prospective study. Setting: The Department of Gynecology and Obstetrics of the Teaching Hospital and the 2nd Medical Faculty of the Charles University Prague. Methods: During the 3 years we followed-up 47 heroin-addicted women and 60 women under substitution therapy for prenatal screening. Of this number, 36 pregnant women were methadonesubstituted and 24 buprenorphine-substituted. All women were screened for socioeconomic indicators, for duration of pregnancy, weight gain during pregnancy, number of visits in the prenatal centre, complications associated with intravenous application of drugs and the way of delivery. Individual groups were compared using the Kruskal-Wallis ANOVA test. Correlation of dichotomic variables was evaluated by means of longlinear models. Calculations were done by means of NCSS 2002 statistical software. Results: Statistically, the age of heroin-dependent women is significantly lower as compared to women receiving substitution therapy. Unemployment was statistically significantly higher in the group using heroin as compared to both groups of women receiving substitution therapy (p<0.001). Attending the prenatal centre were all buprenorphine-substituted women, 14 of 44 heroin-addicted women and 32 of 36 methadone-substituted women. Statistically no significant difference was found when comparing duration of pregnancy of heroin-addicted women and the buprenorphine- or methadone substituted women. Weight gain during pregnancy was statistically significantly higher in the buprenorphine users as compared to the heroin users (p<0.01) as well as with the methadone users (p<0.05). Conclusion: Clients in substitution programme stabilized in the long run often start to work, complete their education and are able to be involved in normal social activities. In these women, pregnancy is significantly more often wanted and planned, as well. As a result they have a responsible approach to the prenatal care.

        Key words: heroin, methadone, buprenorphine, substitution