Background: Prenatal screening for chromosomal abnormalities is routinely offered to all pregnant women who present for care by their 20th gestational week. Not all women, however, choose to undergo one of these tests, and choice of which test(s) to undergo also vary. The reasons for variation in screening test behavior have not been fully explored. Methods: We examined the psychometric properties of scales developed to measure factors related to prenatal screening using data collected as part of a survey of 448 racial/ethnically diverse pregnant women. These women were consecutively recruited from prenatal care clinics when they were between their 12th and 20th week of pregnancy. The Theory of Reasoned Action was used to develop to measures of attitudes toward and beliefs about prenatal screening. All items were subjected to factor analysis. Scales identified in the factor analysis were then subjected to reliability analysis. All analysis was conducted for the entire study group as well as separately for each racial/ethnic group. Results: Six scales emerged: who makes medical decisions, fatalism, health care trust, value of screening, fear of screening and value of pregnancy. All scales had adequate reliability when the analysis was conducted for the entire study group; however there were differences in reliability across racial/ethnic group. Conclusions: Because of these between group differences comparisons of racial/ethnic group may be difficult to interpret and potentially lead to erroneous conclusions.