Impact of pregnancy on the progression of diabetic retinopathy in Type 1 diabetes

Aims To evaluate the impact of pregnancy on the progression of diabetic ret inopathy in women with Type I diabetes mellitus and to identify risk factor s for the progression of retinopathy during pregnancy. Methods One hundred and seventy-nine pregnancies in 139 women with pregesta tional Type 1 diabetes were studied prospectively between January 1990 and December 1998. Dilated fundal examination was performed at present at booki ng, 24 weeks and 34 weeks or 4-6 weekly if retinopathy booking. Data were c ollected on glycaemic control (HbA(1c)) throughout pregnancy. Results Progression to proliferative retinopathy was seen in four (2.2%) pr egnancies while moderate progression was seen in a further five (2.8%) preg nancies. Progression of retinopathy was significantly increased in women wi th duration of diabetes 10-19 years compared with duration <10 years (10% v s. 0%; P=0.007) and in women with moderate to severe background retinopathy at booking (30% vs. 3.7%; P=0.01). Although HbA(1c) at booking was higher (7.5% vs. 6.6%; P=0.08) and the fall in HbA(1c) between booking and 24 week s was greater (1.6% vs. 1.2%; P=0.2) in those women showing progression of retinopathy, these changes were not significant. Conclusions Progression of retinopathy in pregnancy was uncommon (5.0% preg nancies) but was significantly more common in women with duration of diabet es >10 years and in women with moderate to severe retinopathy at baseline. Laser therapy was needed in 2.2% pregnancies, which is much lower than that reported in earlier studies.