Extra-cardiac abnormalities (ECAs) are associated with congenital heart diseaseCongenital heart disease (CHD) in up to 70% of fetuses. Characteristic patterns of association may suggest an underlying geneticGenetics condition. Alternative aetiologies include maternal metabolic disordersMetabolic disorders, infectionsInfections, exposure to drugs and teratogens. The co-existence of ECAs and CHD may profoundly affect prognosis leading to significant morbidity and mortality within this group. If CHD is detected it is crucial to perform a detailed fetalFetal anatomy survey searching for ECAs. Recognition of associated abnormalities and knowledge of underlying causes is important to allow targeted investigations including geneticGenetics testing and appropriate counsellingCounselling. The aim of this chapter is to supportSupport the reader in daily practice by reviewing, with wide use of images, the most common aetiologies that must be considered for the diagnostic work-up of fetuses affected by CHD and ECAs.