The evolution of insulin requirements in 9 pregnant women with insulin-dependent diabetes mellitus (type I) was evaluated. Requirements were increased between weeks 11 and 24 and remained stable between weeks 24 and 35. Those corresponding to breakfast in the two initial connections were significantly higher, while those corresponding to breakfast, lunch and dinner became equal in the last connection (35 gestational weeks). We found a significant lineal correlation between the intravenous and the subcutaneous requirements. We conclude that the artificial pancreas is a useful instrument, which permits a detailed analysis of the time course of intravenous insulin requirements during pregnancy in the insulin-dependent pregnant woman and facilitates the adjustment of insulin therapy.