The term prenatal diagnosis has historically been synonymous with amniocentesis and the prenatal detection of Down Syndrome. In the 1970s, a woman’s choice in assessing her fetus for birth defects and chromosome or genetic conditions was limited. However, continued technical advances in fetal imaging and molecular genetics coupled with the identification of biochemical markers in maternal serum which could be associated with fetal chromosome and/or genetic disorders have drastically changed and expanded the topography of prenatal diagnosis/screening. Edith Cheng, from University of Washington obstetrics and gynecology, summarizes the history and evolution of prenatal diagnosis to its current state with examples of the myriad of choices now available to all women. From the Series:Laboratory Medicine Grand Rounds