Cesarean scar pregnancy (CSP) is a “new, manmade medical condition” of the twentieth century. It can occur only after a prior cesarean delivery or deliveries or after a prior CSP1,2; it is essentially an iatrogenic and late consequence of an earlier cesarean delivery (CD). Over the latter part of the twentieth century, and indeed in the past several decades, CDs have dramatically increased. In 1965, the total CD rate was 4.5%; by 1985, the rate rose to 22.7%, reaching a peak of 32.9% in 2009; however, during the last several years this rate has slowly decreased and the preliminary data for 2014 revealed that the overall CD is 32.2%.3,4Complications of CD include both maternal complications at the time of the first or repeat surgical procedures. In a subsequent pregnancy, complications can occur during the antenatal period such as bleeding from a placenta previa and/or abnormally adherent placenta or even uterine rupture. Regardless of the gestational age many of these complications can be catastrophic for both mother and neonate.5In the continuum, or spectrum, of placental attachment disorders CSP is a common starting point and eventually progresses to early second-trimester placenta accreta, ultimately resulting in the well-known clinical picture of morbidly adherent placenta (MAP) classically seen in the late second and third trimesters.6-8Placental adherence disorders are discussed in a separate chapter.