Background: Although maternal serum screening (MSS) for Down's syndrome has become routinely available in most obstetric clinics in many countries, few studies have addressed the reasons why women agree to undergo the MSS test. Objectives: The aims of this study were to describe the circumstances in which MSS was offered to pregnant women and their reasons for undertaking it. Methods: Participant observation and in depth interviews were used in this study; specifically, the experiences of women who had a positive result for MSS and who then followed this up with amniocentesis were examined. The interviewees were twenty six mothers aged between 22 and 35 years. The interviews were audio taped and transcribed for analysis. The results were analysed by the constant comparative method. Results: This study identified the reasons on which pregnant women appeared to base their decisions when undergoing MSS. The reasons were first, the recognition that the procedure was a prenatal routine procedure; second, the need to avoid the risk of giving birth to a baby with Down's syndrome, and third, a trust in modern technology and in the professional authorities. Conclusions: This study offers insights into the informed choice made by women with a positive MSS result. The reasons for undergoing MSS might help health professionals and policy makers to reflect on their practice and this may, in turn, improve the quality of prenatal care during MSS.
