Glucose Tolerance in Gestational Diabetic Women during and after Treatment with a Combination-Type Oral Contraceptive

Abstract

Oral glucose tolerance tests (GTT) were performed periodically in 15 women who had shown abnormal tolerance to glucose in the third trimester, but who had normal tolerance after delivery. Five received a combination of norethindrone, 1 mg, and mestranol, 0.05 mg, as an oral contraceptive cyclically; 10 who practiced other methods of contraception served as controls. Abnormal glucose tolerance recurred in all five women while they were taking the oral contraceptive agent. After cessation of contraceptive therapy, GTT remained diabetic in three cases; GTT temporarily improved, but became abnormal again in the fourth. The fifth patient was lost to follow-up observation after discontinuing contraceptive pills. Three out of the 10 controls showed deterioration of the GTT. Screening tests for diabetes should be performed in the third trimester of pregnancy, or early during contraceptive treatment, as an attempt to identify women with latent diabetes and exclude them from hormonal birth control.