The effect of pregnancy on the progression of diabetic retinopathy

To evaluate the progression and risk factors of diabetic retinopathy during and after pregnancy in patients with diabetes. We checked the medical records of the patients with diabetes who were referred to the Diabetes Center, Tokyo Women's Medical University Hospital (Tokyo, Japan), and were pregnant between August 2004 and September 2010. The patients whose ophthalmic examinations records could not be found (n = 15) were excluded, and thus 93 patients (type 1 = 68, type 2 = 25) were included in the analyses. Data were obtained from the medical record and evaluated. The mean pre-pregnancy HbA1c was 7.1 +/- 0.8 %. All patients were encouraged to maintain HbA1c level of under 7.4 % before pregnancy. At baseline, the percentage of patients with no retinopathy was 78 %, with nonproliferative retinopathy 14 %, and with proliferative retinopathy, 8 %. Progression of retinopathy occurred in 16 (17 %) patients. Two (2 %) had loss of visual acuity and 1 (1 %) underwent laser treatment due to progression of retinopathy. Compared with patients who did not show progression, the patients with progression were characterized by longer duration of diabetes (p < 0.00001), presence of diabetic retinopathy before pregnancy (p < 0.00001) and higher blood pressure in the second trimester (p < 0.05). Frequent ophthalmic examination, especially in patients with a long history of diabetes, is recommended, as well as for patients with presence of diabetic retinopathy before pregnancy. In contrast to previous reports, the progression of retinopathy in this study was lower. This is probably due to our patients' pre-pregnancy tight glucose control and the high ratio of patients with no retinopathy at baseline.