Although significant advances to patient care have been made in various branches of obstetrics and gynaecology, the incidence of preterm birth has not changed in the past 40 years. Indeed there are signs that factors such as low socioeconomic status of some inner city populations, the tendency for women to choose to start a family at an older age and the impact of fertility treatments are leading to an increase in the incidence of preterm delivery. Improved neonatal care over this period has significantly reduced the mortality rate due to prematurity, although it remains the primary cause of neonatal death. The morbidity rate in preterm infants, however, has not substantially changed due largely to the resuscitation of neonates at or close to the limits of gestational age viability. This has inevitably had a tremendous economic impact upon health care systems and upon society in general. Neonatal care in the USA alone cost over $5 billion annually in the 1980s – the vast majority of which was due to prematurity. When one adds the costs of chronic care for some of these infants with major motor and/or mental handicaps as well as the loss of potential earnings, prematurity ranks as one of the most costly of medical complications.