Gestational diabetes screening in subsequent pregnancies of previously healthy patients

OBJECTIVE: 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. STUDY DESIGN: 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 (less than or equal to 140 mg/dL). RESULTS: 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 less than or equal to 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. CONCLUSION: 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.