Purpose
Diabetic Retinopathy (DR) may deteriorate during pregnancy, although findings from prior studies have been conflicting and many are outdated. Here, we report DR prevalence, progression rate and associated risk factors in pregnant women with pre-existing diabetes.
Methods
Pregnant women with type 1 (T1DM) or type 2 diabetes (T2DM) were prospectively recruited from two maternity hospitals in Melbourne (November 2017-September 2019). Eye examinations were scheduled in each trimester and 3-months postpartum. DR severity was graded from retinal photographs. At least 2 examinations (in early and late pregnancy) were required to evaluate DR change. Progression was defined as worsening of DR severity, development of diabetic macular oedema, or the need for laser treatment during pregnancy.
Results
One hundred and forty-seven from 191 eligible women were recruited. At least one eye examination was performed in 130 (88.4%). Mean age was 33.7 years (range 19-47); 62 women (47.7%) had T1DM while 68 had T2DM (median duration 16.5 and 4.0 years, respectively). DR prevalence was 20.8 (95%CI 16.3-26.1) per 100 eyes, with T1DM and higher HbA1c in early pregnancy being significant risk factors. Among the 144 eyes (72 women) with >1 eye examination, 9.7% (95%CI 5.8-15.8) progressed. Elevated systolic blood pressure (risk ratio 10.36, 95%CI 3.14-34.12) and pre-existing DR in either eye (RR 5.07, 95%CI 1.90-13.49) in early pregnancy significantly increased the risk of progression. Type of diabetes was not associated with a greater risk of progression (p=0.141). Sight-threatening disease was observed in 6 eyes (5 women).
Conclusions
Nearly 1 in 10 eyes had DR progression in pregnancy, with almost half of these developing sight-threatening disease. Risk factors included hypertension and pre-existing DR in early pregnancy. Worryingly, 1 in 5 participants did not attend any eye examinations during pregnancy, highlighting the need to address barriers to adherence given the significant risk of worsening DR.