In developed countries such as the United States and the United Kingdom preterm birth is a major public health problem, with the incidence rising over the past 10 years. Preterm birth is also the major cause of infant mortality in these countries. There are wide socioeconomic disparities in the incidence of spontaneous preterm birth, with substantially higher rates among women from more deprived areas both in the UK and internationally. Increases in the UK in the incidence of very preterm birth (before 33 weeks’ gestation) over the past decade have affected all deprivation groups alike, resulting in an increase in the absolute difference in numbers of very preterm births between affluent and deprived areas. Hence the burden of mortality in more deprived areas is increasing and might explain the widening inequalities in infant mortality seen in the UK.The survival rates of very preterm births are well documented, as are the detrimental effect on survival of clinical factors such as early gestation and low birth weight. Little is known, however, about how the survival of very preterm infants varies with deprivation.