Preterm birth results from three clinical conditions: medically indicated (iatrogenic) preterm birth, preterm premature rupture of membranes and spontaneous (idiopathic) preterm birth. Medically indicated preterm birth in the absence of preterm premature rupture of membranes or spontaneous preterm labour  occurs in about 25% of all preterm births with variations from 8.75-35.2% according to reports and studied populations. Medical indications relate to maternal complications such as severe maternal hypertension, abruptio placentae, or endangered fetal well-being, such as intrauterine growth retardation, or non-reassuring fetal state (‘fetal distress’). There are still rare instances of iatrogenic prematurity, when a woman with incorrect dating in electively induced before 37 weeks.