Gestational diabetes mellitus in patients receiving long-term corticosteroid therapy during pregnancy.

Aim: Little data exist on the impact of chronic low dose corticosteroid therapy during pregnancy on gestational diabetes mellitus (GDM).

Method: We compared 25 pregnant women receiving long-term (>4 weeks) corticosteroid for newly diagnosed idiopathic thrombocytopenic purpura (ITP) (study group) and 108 normal pregnant women (control group) in this case-control study. Main outcome measures were 1-h, 50-g and 3-h, 100-g glucose tolerance tests (GTTs). Women in both groups were also screened with 75-g GTT 6 weeks after delivery.

Results: The mean duration of corticosteroid therapy was 9.8+/-4.9 (range 6-25) weeks. Compared with controls, study group patients had a greater prevalence of diagnosed GDM (24.0 vs. 2.8%, P=0.01). Of these patients, 83.3% were diagnosed with GDM at 16 weeks gestation. An impaired 75-g GTT was also more frequent in the study group (P=0.01).

Conclusion: Our findings suggest that long-term corticosteroid therapy may be associated with the development of diabetes in pregnant women and early GTT should be performed in pregnant women on corticosteroid therapy.