Gestational diabetes screening in subsequent pregnancies of previously healthy patients

Our purpose was to evaluate women without gestational diabetes mellitus in an index pregnancy for the likelihood that gestational diabetes would develop and for risk factors for carbohydrate intolerance in a subsequent pregnancy.

A retrospective review of medical records at a teaching hospital universally screening for gestational diabetes identified multiparous women who had been delivered twice between 1994 and 1997 and who, in the first (index) pregnancy, had had a normal result on a screening test with 50 g of glucose used in a "glucola" beverage (< or =140 mg/dL).

In this population with normal glucose screening values in the index pregnancy, 352 (92.4%) of 381 women had at least one risk factor for gestational diabetes. However, none of the 381 women had gestational diabetes in the subsequent pregnancy (0/381, 95% confidence interval < or =1%), including 45 (12. 4%) who had an abnormal result on the 50-g glucose screening test. Regression analysis showed this test result in the index pregnancy (P =.001) to be the only studied variable significantly associated with the 50-g glucose value in the subsequent pregnancy.

Despite a high rate of risk factors for gestational diabetes, women in our population with a normal glucose value in an index pregnancy have a minimal risk (<1%) that gestational diabetes will develop in a subsequent singleton pregnancy within 4 years. This factor may be included in determining whether women should undergo screening for gestational diabetes.