Does Pregnancy Accelerate the Rate of Progression of Diabetic Retinopathy?

Pregnancy may be associated with several ocular changes, including the development of new ocular conditions or modifications of existing conditions. The most common ocular condition modified by pregnancy is diabetic retinopathy. Pregnancy is associated with an increased risk of development and progression of diabetic retinopathy.

The factors associated with its progression include the pregnant state itself, duration of diabetes, amount of retinopathy at conception, blood glucose control, and the presence of coexisting hypertension. Although the rate of regression of diabetic retinopathy at the end of pregnancy or the postpartum period is high, careful monitoring of these patients is necessary to optimize the vision and pregnancy outcomes.

Introduction

Diabetic retinopathy is a common ocular condition that is modified by pregnancy. The factors that influence the development and progression of diabetic retinopathy during pregnancy are outlined in this article. These include the pregnant state itself, duration of diabetes, degree of retinopathy at conception, metabolic control, and the presence of coexisting hypertension. In addition, guidelines for monitoring the ocular status of pregnant diabetic patients are described in this article.

Progression of Diabetic Retinopathy

Several studies have examined whether pregnancy alters the initial development or subsequent progression of diabetic retinopathy. Although some studies have suggested that pregnancy does not affect the course of retinopathy [1–3], most studies do report that pregnancy adversely affects diabetic retinopathy [4–8].

An ancillary study of the DCCT (Diabetes Control and Complications Trial) evaluated pregnancy's effects on diabetic retinopathy and nephropathy [9]. The DCCT was a multicenter controlled clinical trial that compared the effects of intensive treatment with conventional diabetes therapy. A longitudinal analysis was conducted in 180 women who had 270 pregnancies and 500 women who did not become pregnant during an average of 6.5 years of follow-up. In this study, pregnant women had a higher risk of an increase in the level of retinopathy during pregnancy compared with nonpregnant women. In the conventional treatment group, the pregnant women had a 2.48-fold greater risk of worsening of retinopathy from before to during pregnancy compared with the non-pregnant women. In the intensive treatment group, the pregnant women had a 1.63-fold greater risk of worsening of retinopathy in the course of pregnancy compared with the nonpregnant women.

Other studies have supported this observation of worsening of diabetic retinopathy during pregnancy.

The rates of development and progression of diabetic retinopathy during pregnancy range from 16% to 85% [4–9]. Axer-Siegel et al. [5] examined 65 patients with insulin-dependent diabetes who became pregnant. In this study, 26% of patients with no retinopathy at conception had developed mild nonproliferative diabetic retinopathy (NPDR) during the pregnancy's course. In those patients with NPDR at the start of pregnancy, 55% had progression of their NPDR and 22.5% developed proliferative retinopathy requiring panretinal photocoagulation.