evidence: A high-risk pregnancy is a pregnancy where the mother or the fetus has an increased risk of adverse outcomes compared to uncomplicated pregnancies. No concrete guidelines currently exist for distinguishing "high-risk" pregnancies from "low-risk" pregnancies; however, there are certain studied conditions that have been shown to put the mother or fetus at a higher risk of poor outcomes.[1] These conditions can be classified into three main categories: health problems in the mother that occur before she becomes pregnant, health problems in the mother that occur during pregnancy, and certain health conditions with the fetus.[2] In 2012, the CDC estimated that there are approximately 65,000 pregnancies deemed "high-risk" in the United States each year.[3] [...] Pregnancies may be considered high-risk if the mother has certain pre-existing health conditions. These include: