The majority of multiple pregnancies are delivered preterm. Although medical indications relate more to feto-maternal conditions, preterm premature rupture of membranes to infections and idiopathic preterm birth to lifesyle, these risk factors are identified in any category, emphasing that preterm birth has a multifactorial origin. Still, several incidences of preterm birth are not completely explained with a plausible cause for preterm premature rupture of membranes or spontaneous preterm labour suggesting that other causes have yet to be identified. In addition, preterm birth is associated with unrecognized severe congenital anomalies.