Original Article: Epidemiology The importance of postpartum glucose tolerance testing after pregnancies complicated by gestational diabetes

Aims To review postpartum glucose tolerance in women with gestational diabetes and evaluate the role of formal 75 g oral glucose tolerance testing vs. fasting plasma glucose in screening for persistent abnormalities. Methods Retrospective study of 985 pregnancies over a 10 year period in a mixed ethnic cohort of women who underwent follow-up glucose tolerance testing at 6 weeks postpartum. Diagnosis obtained by oral glucose tolerance test was tested against that from the fasting plasma glucose value. Results Therewere272abnormalpostpartumoralglucose tolerancetestresults(27.6%),with109womenidentifiedashaving frank diabetes. Eleven of these (10%) had fasting plasma glucose £6.0 mmol ⁄l, as did 62 of 114 cases of impaired glucose tolerance.Afastingplasmaglucoseconcentrationof ‡6.1 mmol ⁄lcorrectlyidentifiedabnormalglucosetolerancein199of272 cases (sensitivity 0.73). South Asian women were much more likely to have persistent abnormalities of glucose tolerance than were Europeans (32 vs. 15%, v 2 P < 0.0001).