A controlled study of the influence of continuous subcutaneous insulin infusion treatment on diabetic retinopathy during pregnancy.

Forty consecutive pregnant patients with insulin-dependent (Type I) diabetes mellitus were randomized at the end of the first trimester for treatment with conventional insulin therapy (CIT) or continuous subcutaneous insulin infusion therapy (CSII). Nine patients randomized into the CSII group declined the pump treatment. The mean glycosylated haemoglobin (Hb AIc) decreased (p less than 0.001) both in the CIT and the CSII groups with no difference between the groups. Some deterioration in retinopathy was found in 2/18 patients in the CIT group, in 5/13 in the CSII group, and in 3/9 of those who declined the pump treatment. The proportion of patients whose retinopathy progressed did not differ significantly between the groups, and in the majority the deterioration was mild. However, two patients in the CSII group developed acute ischaemic retinopathy, which progressed to proliferative stage in spite of laser treatment. In these two cases the decrease in the Hb AIc level was among the greatest and fastest in the study. These data suggest that a rapid near normalization of glycaemic control by CSII during pregnancy can accelerate the progress of retinopathy in poorly controlled diabetic patients.