The most tenacious and demanding difficulty presented by the pregnancies of diabetic women is the toll of fetal and neonatal deaths they experienced. The very high rates that prevailed in the years before the discovery of insulin continued little improved for some time after the advent of this miraculous panacea; and even appeared to worsen as the therapy enabled many diabetic women to live long enough to become pregnant. Though with the passing years these deaths steadily diminished their frequency was still manyfold increased in the late twentieth century and even in the early years of the twenty-first century (Hawthorne et al., Br Med J 315:279–281, Prospective population based survey of outcome of pregnancy in diabetic women: results of the Northern Diabetic Audit, 1994, 1997; Vääräsmäki et al., Early Hum Dev 59:61–70, Factors predicting peri- and neonatal outcome in diabetic pregnancy, 2000; Penney et al., BJOG 110:315–318, Outcomes of pregnancies in women with type 1 diabetes in Scotland: a national population-based study, 2003; Melamed and Hod, Int J Gynaecol Obstet 104(Suppl 1):20–24, Perinatal death in pregestational diabetes, 2009; Persson et al., Diabetes Care 32:205–209, Obstetric and perinatal outcomes in type 1 diabetic pregnancies: a large, population-based study, 2009). This chapter will examine their associated features. But first the general nature and attributes of such deaths will be considered.