The aim of this paper was to review the literature on the biological effects of a maternal eating disorder (ED) (and relevant comorbidities) in pregnancy on mothers and in particular on the foetus. We also aimed to highlight possible mechanisms of risk for long-term consequences in the offspring. Relevant literature was searched for using PubMed, PsychInfo and Google Scholar and manually through relevant research papers. The consequences of maternal EDs in pregnancy on EDs symptoms, psychopathology and perinatal outcomes are discussed. A developmental model of possible risk mechanisms for adverse long-term nutritional and psychopathological outcomes in the offspring is proposed. Maternal EDs during pregnancy are likely to have important long-term biological effects on the foetus. Further research needs to clarify potential biological risk mechanisms highlighted in this review. Copyright © 2009 John Wiley & Sons, Ltd and Eating Disorders Association.