Purpose: Diabetic retinopathy (DR) in the postpartum remains poorly understood. This study explores the prevalence, typical DR course and risk factors for DR progression in the postpartum.
Methods: Subgroup analysis of a prospective cohort study of pregnant women with type 1 (T1DM) or type 2 (T2DM) diabetes attending two maternity hospitals in Melbourne. Participants had ≥1 eye examination during both pregnancy and up to 12 months postpartum. DR severity was determined through grading of retinal photographs or clinical assessment when photographs were unavailable. Progression was defined as worsening by ≥1 step on the Airlie House classification, development of diabetic macula oedema or the need for laser treatment.
Results: Eighty-seven pregnancies from 86 women were included; 48 had T1DM and 38 had T2DM (median duration 18.0 and 4.0 years respectively). Mean age was 33.4 years (range 21-47). Prevalences of DR and sight-threatening DR (STDR) at 14-26 weeks postpartum were 23.1 (CI 14.5-34.6) and 14.6 (CI 7.2-27.2) per 100 eyes, respectively. Between late pregnancy and 12 months postpartum, progression occurred in 20/160 (13%) eyes while 10/160 (6%) regressed. Progression was more common in the latter 6 months postpartum and associated with existing baseline DR, T1DM (RR 5.03, 95CI 1.52-16.70) and duration of diabetes >10 years (RR 3.52, 95CI 1.38-8.21). Of 13 eyes that progressed during pregnancy, 5 (38%) regressed in the postpartum. Regression was seen in 4/5 (80%) eyes that developed new DR in pregnancy and 0/5 (0%) eyes with proliferative DR (PDR).
Conclusion: Postpartum DR and STDR prevalence was comparable to the non-pregnant diabetic population. Postpartum progression was twice as common as regression, highlighting the importance of postpartum eye screening. Existing baseline DR, T1DM and duration of diabetes >10 years were risk factors. The majority of eyes that progressed during pregnancy did not regress in the postpartum, especially eyes with PDR.