To begin this review, the overall production advantages that might result from segregated production management will be briefly considered, and from a number of perspectives may have little to do with any inherent differences in the growth potential in individual pigs, or sub-populations of pigs. However, there appears to be a substantial area of conceptual overlap, in which the advantages of adopting segregated management of sows and their off-spring may be intimately linked to growing evidence for pre-natal programming of post-natal development. The origins of these programming effects may be very different and in the second part of this review we will address this topic from a biological perspective. Finally, we will return to a consideration of segregated management systems that takes full account of recent information on the biology of pre-natal programming effects. As reviewed by Moore (2005), the origins of segregated parity management systems vary, and have initially been directed to improving the management of the gilt and first litter sow. However, this trend has also simultaneously recognized the problems of co-mingling the progeny of different parity sows, and the advantages to be gained from adopting segregated nursery systems for at least the progeny of parity 1 sows, compared to the progeny of higher parity females. Therefore, there is good reason to think that segregated management of these offspring at the nursery level will bring overall improvements to a production system. Collectively, the aspects of segregated parity management may open a Pandora’s box of functional nutrients that will be cost-effective when applied to sows at specific stages in their reproductive life cycle. However, there should be as much focus on the quality, as on the quantity, of pigs produced per sow lifetime. This review hopefully provides the reader with an understanding of the very complex interactions that determine the development of a market pig from conception to consumption. In the new era of epigenetic regulation of pre-natal development, and expanding information on the mechanisms controlling various levels of IUGR, the profound influence that the environment of the sow can have on the phenotypic characteristics of her offspring are becoming evident. Clearly, simple selection of genetically superior sows and terminal line boars will determine the potential to produce a desired genotype in their terminal line off-spring. However, inappropriate management may interact with this genetic potential to produce a very different outcome. In this review, the profound effects of sow maturity, nutritional management, and their interaction have been considered. Observations from controlled experiments and from the analysis of the reproductive and developmental characteristics of existing commercial dam-line sows indicate the diversity of possible interactions. However, these studies start to provide a better understanding of the reported benefits of segregated parity management. Innovative approaches to addressing the problems, as well as the opportunities, presented by pre-natal fetal programming of post-natal performance will likely be the benchmark of the most profitable pork production systems in the next decade.