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

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.