Diabetes Care, Vol 18, Issue 5 631-637, Copyright © 1995 by American Diabetes Association
Metabolic control and progression of retinopathy. The Diabetes in Early Pregnancy Study. National Institute of Child Health and Human Development Diabetes in Early Pregnancy Study
EY Chew, JL Mills, BE Metzger, NA Remaley, L Jovanovic-Peterson, RH Knopp, M Conley, L Rand, JL Simpson, LB Holmes and al. et
Division of Biometry and Epidemiology, National Eye Institute, National Institutes of Health, Bethesda, MD 20892-2510, USA.
OBJECTIVE--To evaluate the role of metabolic control in the progression of
diabetic retinopathy during pregnancy. RESEARCH DESIGN AND METHODS--We
conducted a prospective cohort study of 155 diabetic women in the Diabetes
in Early Pregnancy Study followed from the periconceptional period to 1
month postpartum. Fundus photographs were obtained shortly after conception
(95% within 5 weeks of conception) and within 1 month postpartum.
Glycosylated hemoglobin was measured weekly during the 1st trimester and
monthly thereafter. RESULTS--In the 140 patients who did not have
proliferative retinopathy at baseline, progression of retinopathy was seen
in 10.3, 21.1, 18.8, and 54.8% of patients with no retinopathy,
microaneurysms only, mild nonproliferative retinopathy, and
moderate-to-severe nonproliferative retinopathy at baseline, respectively.
Proliferative retinopathy developed in 6.3% with mild and 29% with
moderate-to-severe baseline retinopathy. Elevated glycosylated hemoglobin
at baseline and the magnitude of improvement of glucose control through
week 14 were associated with a higher risk of progression of retinopathy
(adjusted odds ratio for progression in those with glycohemoglobin > or
= 6 SD above the control mean versus those within 2 SD was 2.7; 95%
confidence interval was 1.1-7.2; P = 0.039). CONCLUSIONS--The risk for
progression of diabetic retinopathy was increased by initial glycosylated
hemoglobin elevations as low as 6 SD above the control mean. This increased
risk may be due to suboptimal control itself or to the rapid improvement in
metabolic control that occurred in early pregnancy. Excellent metabolic
control before conception may be required to avoid this increase in risk.
Those with moderate-to-severe retinopathy at conception need more careful
ophthalmic monitoring, particularly if their diabetes was suboptimally
controlled at conception.