Sight-Threatening Diabetic Retinopathy During and After Pregnancy—A Nationwide Matched-Cohort Study

Abstract

OBJECTIVE To evaluate the risk of treatment of sight-threatening diabetic retinopathy (DR) defined as panretinal photocoagulation for proliferative DR or anti–vascular endothelial growth factor injections for diabetic macular edema (DME) during and after pregnancy compared with nonpregnant control participants. RESEARCH DESIGN AND METHODS This was a matched cohort study of women with type 1 diabetes who gave birth in 2013–2022 and who had DR levels recorded in the national Danish Registry of Diabetic Retinopathy during and after pregnancy. Control participants consisted of nonpregnant women with type 1 diabetes, individually matched by baseline DR level. Data were collected from relevant national registers from 36 months before pregnancy until 36 months after. RESULTS We included 1,041 pregnant women and 1,041 matched control participants. At baseline, the median duration (interquartile range [IQR]) of diabetes was 13 (6, 19) and 10 (5, 17) years for cases and control participants. Median baseline HbA1c (IQR) was 57 (50, 67) compared with 64 (55, 79) mmol/mol (7.4% vs. 8%), and DR was present in 42.7% of both groups. During and after pregnancy, treatment of proliferative DR with panretinal photocoagulation occurred to a similar extent in both groups (pregnant women vs. control participants: during treatment: 1.2% vs. 1.1%, respectively, OR 1.18 [95% CI 0.53, 2.66]); and after treatment: 2.7% vs. 2.9%, respectively, OR 0.93 [95% CI 0.55, 1.57]). Treatment of DME was rare in both groups. Progression to proliferative DR was not higher in the pregnant group (adjusted hazard ratio 0.64 [95% CI 0.32, 1.31]). CONCLUSIONS In this nationwide register study of women with type 1 diabetes, pregnant women and retinopathy-matched, nonpregnant control participants had a similar risk of developing sight-threatening DR requiring treatment during and within 36 months after pregnancy.