Prevalence of diabetic retinopathy in women with pregestational diabetes during pregnancy and the postpartum.

BACKGROUND: Diabetic retinopathy (DR) may be affected by pregnancy. The majority of prevalence data regarding DR in pregnancy predate the advent of contemporary guidelines for diabetes management during pregnancy. This study reports DR prevalence and associated risk factors in women with pregestational diabetes during pregnancy and the postpartum in Australia. METHODS: A total of 172 pregnant women with type 1 (T1DM) or type 2 diabetes diagnosed pre-pregnancy were prospectively recruited from two obstetrics hospitals in Melbourne (November 2017-March 2020). Eye examinations were scheduled in each trimester, at 3-, 6-, and 12-months postpartum. DR severity was graded from two-field fundus photographs by an independent grader utilising the Airlie House Classification. Sight-threatening DR (STDR) was defined as the presence of diabetic macular oedema or proliferative DR. RESULTS: Overall, 146 (84.9%) women had at least one eye examination during pregnancy. The mean age was 33.8 years (range 19-51), median diabetes duration was 7.0 years (IQR 3.0-17.0), 71 women (48.6%) had T1DM. DR and STDR prevalence during pregnancy per 100 eyes was 24.3 (95% CI 19.7-29.6) and 9.0 (95% CI 6.1-12.9); while prevalence in the postpartum was 22.2 (95% CI 16.5-29.3) and 10.0 (95% CI 5.4-17.9), respectively. T1DM, longer diabetes duration, higher HbA1c in early pregnancy, and pre-existing nephropathy were significant risk factors. CONCLUSIONS: The prevalence of DR in pregnant women was similar to the non-pregnant diabetic population in Australia. One in nine participants had STDR during pregnancy and the postpartum, highlighting the need to optimise DR management guidelines in pregnancy given the significant risk of vision loss.