Illustrating the fascinating intersections of online media and new kinship, this book presents a study of the increasing numbers of single women and lesbian couples reproducing by using donor sperm. It explores how they connect with each other online, develop intimate digital communities and, most importantly, locate their children's hitherto unknown biological half-siblings, throughout the world. The author discusses how these new families - consisting of only mothers - engage in extended families involving large numbers of 'donor siblings'. The new families challenge previous understandings of kinship, and provide illustrations of how norms of gender, sexuality and family are challenged, negotiated and maintained in contemporary times. A crucial study of contemporary formations of family, gender and race, Mediated Kinship discusses the racial aspects of the world's largest sperm bank exporting Danish sperm (termed 'Viking sperm'), and explores the narratives of whiteness and imagined racial superiority that circulate among mothers, as well as the racialisations accompanying commercial online sperm sales. By analysing contemporary families of donor-conceived children in the context of legislation, reproduction technologies and online media, the book will appeal to scholars across the social sciences with interests in race and ethnicity, whiteness, gender, sexuality, kinship and the sociology of the family.