Recent public health concern about the Jacob-Creutzfeld disease related to administration of growth hormone in children or the "mad cow" disease in cattle fed contaminated products requires a review of the association between Jacob-Creutzfeldt disease and pregnancy. Four cases of this transmissible spongiform encephalopathy have been described in pregnant women and none of the offspring, currently 22, 10, 7 and 3 years of age, have developed the disease. Vertical transmission of Jacob-Creutzfeldt disease cannot however be excluded as it occurs in animals and since injections of cord blood and placenta extracts of women with this disease into mice brains has proven the presence of the infectious agent. The rarity of Jacob-Creutzfeldt disease in women of reproductive age and the particularly long incubation period of this type of encephalopathy would incite prudence and long-term follow-up to determine outcome in children born from disease women or who developed signs of the disease during the years following delivery.