A set of 9 models illustrates the detailed stages of pregnancy development. Featuring first month embryo, second month embryo, third month embryo, fourth month fetus, fifth month fetus, fifth month twin fetuses (normal position), fifth month twin fetuses (transverse lie), and seventh month fetus (left and right position). The embryo from the third month, as well as the fetuses from months four through seven can be removed for closer examination. Each model is mounted on a stand and a corresponding key card is included.