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

Abstract

To evaluate the impact of pregnancy on the progression of diabetic retinopathy in women with Type 1 diabetes mellitus and to identify risk factors for the progression of retinopathy during pregnancy. One hundred and seventy-nine pregnancies in 139 women with pregestational Type 1 diabetes were studied prospectively between January 1990 and December 1998. Dilated fundal examination was performed at booking, 24 weeks and 34 weeks or 4-6 weekly if retinopathy present at booking. Data were collected on glycaemic control (HbA(1c)) throughout pregnancy. Progression to proliferative retinopathy was seen in four (2.2%) pregnancies while moderate progression was seen in a further five (2.8%) pregnancies. Progression of retinopathy was significantly increased in women with duration of diabetes 10-19 years compared with duration < 10 years (10% vs. 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 weeks was greater (1.6% vs. 1.2%; P = 0.2) in those women showing progression of retinopathy, these changes were not significant. Progression of retinopathy in pregnancy was uncommon (5.0% pregnancies) but was significantly more common in women with duration of diabetes > 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. Diabet. Med. 18, 573-577 (2001)