Changes in diabetic retinopathy during pregnancy. Correlations with regulation of hyperglycemia.

Thirty-eight pregnancies in 35 women with insulin-dependent diabetes mellitus were monitored for changes in diabetic retinopathy during the institution of "tight" metabolic control by intensive medical management. Eye findings were scored on paired sets of retinal photographs obtained when enrolled in this study and shortly after delivery. These findings were then correlated with measurements of diabetic regulation. Intensive therapy for the diabetes mellitus resulted in improved glucose control by the time of delivery. However, retinal abnormalities worsened as gestation proceeded in 55% of the pregnancies. Deterioration of background retinopathy correlated significantly with the levels of plasma glucose at entry and with the magnitude of improvement in glycemia achieved during the first six to 14 weeks after entry (ie, "early changes") and by the final week before delivery (ie, "overall changes"). Our findings indicate that the changing retinopathy during pregnancy cannot be interpreted without assessment of concurrent changes in the regulation of maternal diabetes and that the abrupt institution of improved diabetic control during pregnancy may be one factor in the deterioration of background retinopathy sometimes seen during pregnancy.