The Diabetes Control and Complications Trial (DCCT) Research Group is to be congratulated on its careful analysis of the retinal changes in pregnancy in women who participated in the trial (1). This analysis was able to demonstrate both a genuine “pregnancy effect” and an “early worsening effect” of tightening glycemic control as independent contributors to the well-recognized phenomenon of deterioration in retinopathy during pregnancy. Because comparable data are unlikely to ever be accumulated, this letter will probably stand as the last word on the subject.
However, one important point was not addressed in the article: whether women who had no retinopathy immediately before or early in pregnancy ever developed in later pregnancy or postpartum retinopathy of sufficient severity to warrant intervention by an ophthalmologist. Other prospective studies have found that, although up to 33% of such women develop background changes during pregnancy, the retinopathy is mild in degree, does not require intervention, and regresses postpartum (2–8).
Thus, the injunction in the DCCT Research Group’s article, that all women with type 1 diabetes should have intensive retinal surveillance during pregnancy and postpartum (1), does not seem to have sound evidence to support it—even though it accords with the recommendations of an earlier review (9). It is important that all diabetic women have their eyes examined in early pregnancy, but the literature suggests that only those who have retinopathy detected before or early in pregnancy and those who are without retinopathy but have particularly poor glycemic control require intensive ophthalmologic surveillance.
Intensive surveillance is demanding. A recent review (9) suggests that it should involve a complete eye examination at least every trimester and within 3 months postpartum. Women with type 1 diabetes already have a lot to contend with during pregnancy. Should those that do not need intensive surveillance be burdened with resource-consuming and, arguably, unnecessary visits for retinal examination? This group is not trivial in number—more than half of the intensively treated patients in the DCCT study had no retinopathy on their first examination (1).
The American Diabetes Association’s Clinical Practice Recommendations seem ambiguous on this point. The position statement on preconception care states that follow-up ophthalmologic examinations should be “anticipated” during pregnancy for all women with diabetes (10); yet, the position statement on diabetic retinopathy states that the frequency of follow-up should depend on the result of the first trimester examination (11).
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Address correspondence to Tim Cundy, MD, Auckland Hospital, Park Rd., Auckland 1, Auckland, New Zealand. E-mail: [email protected].