Previous gestational diabetes mellitus may substantially increase future diabetic retinopathy risk in women who later develop diabetes. A nationwide register-based cohort study published in Diabetes Care evaluated whether prior GDM, GDM severity, and postpregnancy hypertension were associated with future DR risk in women with diabetes. 

The analysis included all women giving birth in Denmark between 1997 and 2018. Gestational diabetes mellitus and diabetic retinopathy were identified using ICD-10 codes, while GDM severity was estimated according to insulin treatment during pregnancy. Subsequent diabetes and hypertension were identified through diagnostic codes and medication records. Cox regression analyses were used to assess risk associations. The study included 708,250 women with a median follow-up of 12 years.

Findings

• Subsequent diabetes developed in 18,556 women, among whom 655 developed DR.
• In women who later developed diabetes, prior GDM was associated with a threefold higher DR risk (adjusted hazard ratio [aHR] 3.0; 95% confidence interval [CI] 2.6-3.6).
• DR risk was highest among women with insulin-treated GDM (aHR 5.6; 95% CI 4.5-6.9) and remained elevated in women with non–insulin-treated GDM (aHR 2.4; 95% CI 2.0-2.9), compared with women without previous GDM.
• Among women with postpregnancy hypertension, prior GDM was associated with a 2.7-fold higher DR risk (aHR 2.7; 95% CI 2.1-3.5).

Previous GDM was associated with substantially higher DR risk in women who later developed diabetes, with greater risk observed after insulin-treated GDM and postpregnancy hypertension. The findings suggest GDM history may help refine future DR risk assessment and screening strategies.