Figure 1: A flow-chart showing effects of maternal smoking related factors on fetal kidney development. Maternal smoking causes fetal growth retardation and underdeveloped kidney through multiple mechanisms, including fetal DNA modifications, direct impacts of chemicals in the cigarette smoke, changes in growth factors in the fetus and reduced fetal nutrition supply due to maternal under nutrition and placental blood flow restriction induced by cigarette smoke. Maternal genetic defects can also have a direct impact on fetal kidney development and the predisposition of kidney disorders later in life.