Extreme preterm birth interferes with the development of the cardiovascular system. Both macro- as well as microvasculature undergoes extensive, organ specific maturation. Under normal fetal conditions, microvascular growth drives renal development and continues until 34-36 weeks of gestational age, while retinal vascular growth continues until term age. Studies show that there is association between low birth weight and cardiovascular dysfunction. According to the Barker hypothesis, this is due to nutritional shortage. In extreme preterm birth cases, this growth restriction is observed in neonatal life.