Several of choices in maternity, such as antenatal screening for Down syndrome, have important implications for women and thus informed choice has fundamental importance. The choice to undergo screening for Down syndrome should be based on a full understanding of the likely benefits, harms and limitations of screening. Many definitions have been given for informed choice but all these definitions have two core characteristics: a) relevant, good quality information and b) consistency between attitudes and behaviour. An informed decision could be defined as a reasoned choice which is made by a reasonable individual using relevant information about the advantages and disadvantages of all possible courses of action in accord with the individuals belief. The conclusions that have been drawn from this literature review concern mainly the measurement, the determinants and the factors that may impact on informed choice. Regarding the measurement of informed choice, it could be concluded that there is a lack of standardized measures that assess the multidimensionality of informed choice because often measures of informed choice are ether single dimensioned measures or measures of self report. Concerning the knowledge which is one of the determinants of the informed choice, has been concluded that: a) level of knowledge adequate for informed decision making have not achieved, b) women’s knowledge is influenced by the way of presentation of information and by the knowledge of healthcare professional, c) a considerable amount of given information concerning the results of screening is not easily understandable by women because of the numerical approach of information and thus d) knowledge is not the same as understanding. It has been also concluded that the professional recommendation concerning the given information about screening for Down syndrome may be inadequate because they don’t include information about the condition of Down syndrome. Health care professionals (midwives and obstetricians) should dedicate more time to discussing with women and should provide information which is understandable and suitable to their learning ability. Moreover, concerning the women’s attitude which is another determinant of informed choice could be concluded that attitude is a stronger determinant of informed choice than knowledge since many women who stated that the received information from health professional was useful and adequate didn’t make an informed choice finally. Therefore, the tempt to increase attitude-behavior consistency could be more successful in increasing informed choice in screening for Down syndrome than increasing the level of knowledge.