Determining the course of diabetic retinopathy from pregnancy to the postpartum in women with pre-existing diabetes in metropolitan Melbourne

Abstract

Purpose : The effect of the postpartum on diabetic retinopathy (DR) remains unknown. Understanding this can inform whether sight-threatening DR (STDR) is best treated during pregnancy or can be deferred till after delivery. This study explores the prevalence, typical DR course and risk factors for DR progression in the postpartum.

Methods : Subgroup analysis of a prospective longitudinal cohort study of pregnant women with type 1 (T1DM) or type 2 diabetes (T2DM) attending two tertiary maternity hospitals in Melbourne, Australia (Nov 2017 – Sept 2020) who had at minimum one eye examination in pregnancy and one up to 12 months postpartum. DR severity was determined either through grading of 2-field retinal photographs or clinical assessment when fundus photographs were unavailable. Progression was defined as worsening by ≥1 step on the Airlie House classification, development of diabetic macula edema (DME) or the need for laser treatment.

Results : This analysis included 87 pregnancies from 86 women; 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). DR prevalence at ≥27 weeks postpartum was 26.3 (CI 16.6, 39.0) per 100 eyes. 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 DR at enrolment, T1DM (RR 5.03, CI 1.52-16.70) and duration of diabetes >10 years (RR 3.52, 1.38-8.21). Of the 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, 1/5 (20%) eyes with pre-existing non-proliferative DR and 0/5 (0%) eyes with proliferative DR (PDR). Eyes with DME had good vision (20/40 or better) at the majority of their exams (92%, 49/53), with 53% (9/17) resolving in the postpartum.

Conclusions : The postpartum prevalence of DR was comparable to the non-pregnant diabetic population. Progression in the postpartum was twice as common as regression, highlighting the need for adequate postpartum eye screening. In eyes that progressed during pregnancy, most did not regress in the postpartum, especially eyes with PDR. Treatment for PDR thus cannot be delayed in anticipation of resolution post-delivery. However, DME treatment can be safely delayed in most cases.

This is a 2021 ARVO Annual Meeting abstract.