Objective The study evaluated patient informed consent for the Quad screen and examined differences in IC between test acceptors and test refusers. A multidimensional model of IC was used. Methods Women seeking prenatal care at nine obstetrics clinics in a large Midwestern city completed surveys between February and December 2006. Surveys contained measures for three dimensions of IC: intention, understanding and controlling influence. Results 56.2% of women did not meet criteria for all three of our dimensions of IC and therefore (...) failed to give it. The failure rate was higher among women who choose to screen than women who choose not screen. Women who met all criteria for IC were over three times less likley to choose to screen ) than women who did not meet criteria for IC. Conclusion The decision to screen for fetal anomalies is less of a deliberated action than the decision not to screen. Women who lack a fundamental understanding of the purpose and nature of the screen may be operating on the belief that the screen is part of standard care and presents no need to deliberate. (shrink)