Metabolic control and serum hormone levels in relation to retinopathy in diabetic pregnancy

The occurrence and progression of retinopathy were related to the mean blood glucose levels and the serum concentrations of prolactin, human placental lactogen, oestradiol and progesterone in 57 pregnant insulin-dependent diabetic patients. Fifteen patients had frank retinopathy, of whom eight showed a marked increase in retinopathy. The initial blood glucose levels were significantly higher in patients whose retinopathy progressed, whereas during the second and third trimester similar blood glucose levels were achieved in all groups. Serum concentrations of progesterone and human placental lactogen were significantly increased in diabetic patients during the last trimester when compared with those in normal pregnancies, and during the second trimester, patients with retinopathy showed significantly higher concentrations than those without, but no significant difference was found in oestradiol values. The eight patients with progressive retinopathy showed progesterone, human placental lactogen and oestradiol levels at or above the upper limit of the normal range. Throughout gestation, serum prolactin concentrations were significantly lower in diabetic patients than in healthy subjects. No correlation was found between serum prolactin values and the occurrence of retinopathy.