Multiple independent factors impact the course and outcome of pregnancy. Figure 2.1 represents a schematic diagram of many of these factors and their interrelationship during the course of pregnancy. Prior to conception, a number of factors combine to provide the background environment in which subsequent pregnancies will develop. In particular, a complex interaction between the patient-related factors and environmentally related factors contributes to the likelihood of pregnancy, prenatal course, pregnancy outcomes, and postpartum complications.