Aim of the study: To identify changes in reproductive health status as a consequence of changes in the system of health care and social affairs. The aim of this part of study: To prepare the methodology of data collection and to identify changes of demographic characteristics. Type of the study: Retrospective comparative epidemiological study. Institution: Institute for the Care of Mother and Child, Praha 4 - Podolí. Methods: Two nation-wide surveys on reproductive health of representative three-stage cluster samples in 1993 and 1997. After selection of residential sites from all districts the households were selected for interview. One hundred and fifty trained interviewers asked selected women of reproductive age (4,497 in 1993 and 1,735 in 1997) questions according to a special questionnaire. The basic demographic characteristics of the two samples were compared with the 1991 Census data. The 1993 Czech Republic Reproductive Health Survey was funded by the United States Agency for international Development via a WHO agreement; the 1997 Survey was funded by the Czech Statistical Office and Ministry of Health. Results: The age structure is very similar in the 1993 sample and in the 1991 Census data, how- ever, there is a remarkably lower proportion of women 15-19 years of age in the 1997 sample. According to the marital status, the 1997 sample has a higher proportion of women living in partner-strip and divorced women. The 1997 sample has a higher proportion of women with only one child and there were fewer women with 4 and more children. Also the proportion of women with secondary education with higher school certificate was higher in the later sample. Conclusion: This part of the study evaluate a changes in four demographic characteristics of women of reproductive age, because these changes could influence the reproductive health indi- cators (contraception, induced abortions), which are the subject of further analysis.

        Key words: reproduction, epidemiology, reproductive age, probability sample, demographic char- acteristics