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.

Diabetic   retinopathy   that   develops   during   the pregnancy’s course may demonstrate a high rate of spontaneous regression after delivery. In the Axer-Siegel et al. [5] study of patients with no retinopathy at onset who then developed mild NPDR during pregnancy, 50% had complete regression and 30%  had partial regression of their disease after delivery. Regression rates were not as high for patients with mild NPDR at onset that progressed to severe NPDR during pregnancy.  In this group,  only 17%  had total regression and 58%  had partial regression of their disease after delivery.  Diabetic macular edema may also occur during pregnancy [10,11]. Similar to retinopathy,  a high rate of spontaneous regression exists postpartum.

Disclosure
This work is supported in part by an unrestricted grant from the Research to Prevent Blindness, New York, NY.

References

1. Lapolla A, Cardone C, Negrin P, et al.: Pregnancy does not induce or worsen retinal and peripheral nerve dysfunction in insulin-dependent diabetic women. J Diabetes Complications 1998, 12:74–80.
2.   Lovestam-Adrian M, Agardh CD, Aberg A, Agardh E: Pre-eclampsia is a potent risk factor for deterioration of retinopathy during pregnancy in type 1 diabetic patients. Diabet Med 1997, 14:1059–1065.
3.   Horvat M, Maclean H, Goldberg L, Crock GW: Diabetic retinopathy in pregnancy: a 12-year prospective survey. Br J Ophthalmol 1980, 64:398–403.
4.   Sunness JS: The pregnant women’s eye. Surv Ophthalmol 1998, 32:219–238.
5.   Axer-Siegel R, Hod M, Fink-Goldman S: Diabetic retinopathy during pregnancy. Ophthalmology 1996, 103:1815–1819.
6.   Phelps RL, Sakol P, Metzger BE, et al.: Changes in diabetic retinopathy during pregnancy. Arch Ophthalmol 1986, 104:1806–1810.
7.   Best RM, Chakravarthy U: Diabetic retinopathy in pregnancy. Br J Ophthalmol 1997, 81:249–251.
8.   Moloney JB, Drury M: The effect of pregnancy on the natural course of diabetic retinopathy. Am J Ophthalmol 1982, 93:745–756.
9.   The Diabetes Control and Complications Trial Research Group: Effect of pregnancy on microvascular complications in the Diabetes Control and Complications Trial. Diabetes Care 2000, 23:1084–1091.
10. Sinclair SH, Nesler C, Foxman B, et al.: Macular edema and pregnancy in insulin-dependent diabetes. Am J Ophthalmol 1984, 97:154–167.
11. Stoessel KM, Liao PM, Thompson JT, et al.: Diabetic retinopathy and macular edema in pregnancy. Ophthalmology 1991, 98(Suppl):146.
12. Klein BE, Moss SE, Klein R: Effect of pregnancy on progression of diabetic retinopathy. Diabetes Care 1990, 13:34–40.
13. Lauszus F, Klebe JG, Bek T: Diabetic retinopathy in pregnancy during tight metabolic control. Acta Obstet Gynecol Scand 2000, 79:367–370.
14. Klein BE, Davis MD, Segal P, et al.: Diabetic retinopathy assessment of severity and progression. Ophthalmology 1984, 91:10–17.
15. Sinclair SH, Nesler CL, Schwartz S: Retinopathy in the pregnant diabetic. Clin Obstet Gynecol 1985, 28:536–552.
16. Chew EY, Mills JL, Metzger BE, et al.: Metabolic control and progression of retinopathy. Diabetes Care 1995, 18:631–637.
17. Kitzmiller JL, Main E, Ward B, et al.: Insulin lispro and the development of proliferative diabetic retinopathy during pregnancy. Diabetes Care 1999, 22:874–876.
18. Buchbinder A, Miodivnik M, McElvy S, et al.: Is insulin lispro associated with the development or progression of diabetic retinopathy during pregnancy? Am J Obstet Gynecol 2000, 183:1162–1165.
19. Loukovaara S, Immonen I, Teramo KA, Kaaja RR: Progression of retinopathy during pregnancy in type 1 diabetic women treated with insulin lispro. Diabetes Care 2003, 26:1193–1198.
20. Rosenn B, Miodovnik M, Kranias G, et al.: Progression of diabetic retinopathy in pregnancy associated with hypertension in pregnancy. Am J Obstet Gynecol 1992, 166:1214–1218.
21. Schocket LS, Grunwald JE, Tsang AF, et al.: The effects of pregnancy on retinal hemodynamics in diabetic versus non-diabetic mothers. Am J Ophthalmol 1999, 128:477–484.
22. Larsen M, Colmorn L, Bonnelycke M, et al.: Retinal artery and vein diameters during pregnancy in diabetic women. Invest Ophthalmol Vis Sci 2005, 46:709–713.
23. Chen HC, Newsom RS, Patel V, et al.: Retinal blood flow changes during pregnancy in women with diabetes. Invest Ophthalmol Vis Sci 1994, 35:3199–3208.
24. Loukovaara S, Harju M, Kaaja R, Immonen I: Retinal capillary blood flow in diabetic and nondiabetic women during pregnancy and postpartum period. Invest Ophthalmol Vis Sci 2003, 44:1486–1491.
25. Four risk factors for severe visual loss in diabetic retinopathy. The Diabetic Retinopathy Study Research Group [no authors listed]. Arch Ophthalmol 1979, 97:654–655.
26. Diabetic Retinopathy. Preferred Practice Patterns [pamphlet]. San Francisco, CA: The American Academy of Ophthalmology; 2003.

Provides American Academy of Opthalmology guidelines for monitoring acute changes in pregnant diabetic patients.

Corresponding author
Bhavna P. Sheth, MD
Eye Institute, Medical College of Wisconsin, 8701 Watertown Plank
Road, Milwaukee, WI 53226, USA.
E-mail: .(JavaScript must be enabled to view this email address)
Current Diabetes Reports 2008, 8:270–273
Current Medicine Group LLC ISSN 1534-4827

Bhavna P. Sheth, MD