Prematurity as a result of preterm birth is the major cause of perinatal mortality and morbidity in the developed world (Fig. 1). The world-wide prevalence of preterm birth (PTB) is 13 million births per year, though the incidence ranges from 5.8% in Oceania to 12% in North America. The incidence of preterm birth in Europe is 5.8%, or approximately 400,000 preterm births per year. After the exclusion of elective deliveries, contraindications to intervention and shortage of availability to good quality antenatal care, there are around 100,000 preterm births per year in Europe that are potentially preventable. Maternofetal complications are responsible for elective preterm birth in approximately 20% cases of elective preterm birth, and the remainder are due to spontaneous preterm labor (SPTL) and preterm prelabour rupture of the membranes (PPROM).2 At the time of presentation in SPTL tocolytics and glucocorticoids may be administered but at this stage it may be too late to intervene as irreversible changes in the cervix may have occurred. Medical intervention in labor may be absolutely contraindicated due to conditions such as lethal congenital malformation, fulminating pre-eclampsia or infection. Relative contraindications to intervention include ruptured membranes, antepartum haemorrhage, intrauterine growth restriction and insulin dependent diabetes.