Introduction

Inadequate fetal nutrient supply and the resulting intrauterine growth restriction (IUGR) and premature delivery continue to cause unacceptably high rates of infant mortality and morbidity throughout the world. Indeed in the relatively affluent UK, recent statistics reveal that the incidence of low birth weight (<2500 g) has increased from 67 per 1000 births in 1989 to 78 per 1000 births in 2006 (Fabian Society, 2006). While these figures may in part reflect both the changing ethnic makeup of UK society and the increased availability of assisted conception procedures and hence multiple births, the trend is worrying as both premature delivery and low birth weight are associated with a lifetime legacy of health issues. For the extremely small and premature baby there is an increased risk of cerebral palsy, autism, visual and aural impairment, and of experiencing developmental problems such as low IQ, poor cognitive function and learning difficulties with their obvious social, ethical and economic costs (Hack & Merkatz, 1995). In addition, there is compelling evidence from a large number of epidemiological studies that low birth weight, even within the normal range, is a major risk factor for the subsequent development of metabolic syndrome and its co-morbidities, particularly when the infant is born into a calorie-rich environment (Barker, 1998, 2006). It is axiomatic that reducing the incidence of low birth weight is a major research priority with the potential to impact immediate survival and lifelong health of the individual.