The authors have presented their experiences on prenatal screening of fetal trisomies in this second part of a prospective study between 1988 and 1990. They gained their conclusions by processing 63,496 pregnancies during three years. The results show that maternal age plays the most important role in the prenatal screening of fetal trisomies in Hungary. They recommend fetal karyotyping for every pregnant woman aged 35 years or more. They emphasized that using of a combined screening method (i.e. maternal age, serum alpha-fetoprotein, human chorionic gonadotropin, oestriol) is only permissible if the hormonal and cytogenetic laboratory background are provided under standard circumstances. Since these are not available for the vast majority of pregnant women in Hungary they concluded that, at least for the time being, the main criteria for prenatal screening of fetal trisomies is the maternal age. By applying this recommendation 25-30 percentage of Down syndrome fetuses can be detected.