Objectives: Prenatal screening for Down syndrome has become standard practice in many western countries. In the Netherlands, however, prenatal screening tests for congenital defects are not offered routinely. The present study aims to assess test uptake in a large, unselected population of pregnant women, and to give more insight into the decision for or against prenatal screening through nuchal translucency measurement or maternal serum screening. Patients and Methods: The study is part of a randomized controlled trial with two groups, each being offered a different prenatal screening test, and a control group. Pregnant women received postal questionnaires at three stages of their pregnancy. Results: Of the women being offered the nuchal translucency measurement or the second trimester maternal serum test, 53 and 38% respectively accepted the test offer. The main reasons for accepting were 'gaining knowledge about the health of the foetus/curiosity' (50%), 'favourable characteristics of the screening test' (18%), and 'increased risk of having a child with DS' (15%). The main reasons for declining were 'unfavourable characteristics of the screening test' (42%), 'not applicable/not necessary' (35%), 'anxiety/uncertainty' (36%), 'adverse characteristics of the invasive tests' (32%), and 'being against abortion' (15%). Discussion: The uptake of prenatal screening was relatively low, and different distributions of reasons were reported, compared to other studies. These differences may be due to the specific Dutch situation in which prenatal screening is not part of standard prenatal care. The question arises as to whether informed decision-making would be reduced if prenatal screening became routinised. Copyright © 2005 John Wiley & Sons, Ltd.