The term premature is employed to define a baby delivered before 37 weeks of amenorrhea, or absence of periods, which is also called preterm birth, whereas normal pregnancy lasts for 40 weeks. Between 32 and 37 weeks, it is called preterm birth, between 28 and 32 it is severe prematurity, and before 28 the child is considered extremely premature, given that a baby born before 22 weeks of gestation is not considered as a baby. These cases represent 6% of births in the world. There are a number of causes of an increased risk of premature birth, notably maternal infection, multiple pregnancies, smoking during pregnancy, and more. Premature birth can sometimes be induced out of necessity. Depending on how premature the baby is and the surrounding circumstances, a premature child is sometimes hospitalized in the neonatal department and can be administered special medication designed to help with organ development, notably the lungs, then follow-up and particular postnatal care.