We investigated glucose tolerance after cesarean section in 24 women with gestational-onset diabetes (group A), in 18 women with an adverse pregnancy outcome (group B), and in 19 healthy pregnant women (group C). Glucose tolerance was performed within six days as well as six weeks after delivery. Eleven (45.8%) women in group A, five (27.8%) in group B and one (5.2%) in group C showed glucose intolerance immediately after delivery. Six weeks after delivery, 18 (75%) women in group. A showed normal glucose tolerance (NGT), four (16.6%) impaired glucose tolerance (IGT) and two (8.3%) diabetes according to WHO criteria. NGT showed 16 (88.8%) women in group B, and 19 (100%) in group C, while two (11.1%) women in group B presented with IGT. We conclude that a glucose tolerance test both immediately and six weeks after delivery is useful not only in women who have gestational diabetes but also in women with an adverse pregnancy outcome.