The invention concerns the identification of proteomes of biological fluids and their use in determining the state of maternal/fetal conditions, including maternal conditions of fetal origin, chromosomal aneuploidies, and fetal diseases associated with fetal growth and maturation. In particular, the invention concerns the identification of the proteome of amniotic fluid (multiple proteins representing the composition of amniotic fluid) and the correlation of characteristic changes in the normal proteome with various pathologic maternal/fetal conditions, such as intra-amniotic infection, or chromosomal defects.