Objective: The purpose of this study was to determine, among women without evidence of gestational diabetes mellitus during their first pregnancy, the likelihood of, and associated risk factors for, the development of gestational diabetes mellitus in the subsequent pregnancy.
Study design: This was a retrospective cohort study, with a time frame of 1991 to 1999.
Results: Of 3710 women without gestational diabetes mellitus in the first pregnancy, 1% (37 women) were subsequently diagnosed with gestational diabetes mellitus in the second pregnancy. These 37 women, when compared (by means) to women without gestational diabetes mellitus in their second pregnancy, were more likely to be older (age 21 years vs 19 years) and obese (first visit body mass index, 28 kg/m(2) vs 25 kg/m(2)) and to have an interpregnancy weight gain of >5 kg (93% vs 49%) and a longer mean interpregnancy interval (33 months vs 24 months). Regression analysis revealed that, during the first pregnancy, a first visit body mass index of >29 kg/m(2) (odds ratio, 2.2; 95% CI, 1.1-4.5) and a serum glucose screen of >101 mg/dL (odds ratio, 8.3; 95% CI, 2.5-27.9) were associated significantly with the development of gestational diabetes mellitus in the second pregnancy, as was an interpregnancy weight gain of >5 kg (odds ratio, 10.8; 95% CI, 2.5-46.3). All women who subsequently had gestational diabetes mellitus had at least one of these risk factors.
Conclusion: Among women without gestational diabetes mellitus in the first pregnancy, the risk of gestational diabetes mellitus in a second pregnancy is low. Therefore, screening all such women in the second pregnancy may not be justified.